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2023
"Plasma mirrors as a path to the Schwinger limit: theoretical and numerical developments"
Vincenti H, Clark T, Fedeli L, Martin P, Sainte-Marie A & Zaim N (2023), The European Physical Journal Special Topics., July, 2023.
Abstract: Following the advent of petawatt (PW)-class lasers already capable of achieving light intensities of 10^23W/cm^2, high-field science now aims at solving a major challenge of modern physics: can we produce extreme light intensities above 10^25W/cm^2beyond which yet unexplored strong-field quantum electrodynamics (SF-QED) regimes would dominate light-matter or even light-quantum vacuum interactions? As the required intensities are orders of magnitude higher than the present record held by a 4 PW laser, solving this major question with the current generation of lasers requires conceptual breakthroughs that we strived to address at CEA-LIDYL over the last 5 years. To break this barrier, we proposed to revive an old concept called the 'Curved Relativistic Mirror' (CRM). Assuming a perfectly reflective and aberration-free CRM, reflecting a high-power laser on such a moving mirror could in principle boost its intensities by several orders of magnitude through Doppler effect. The major obstacle with this simple concept is its actual implementation: how to produce a curved and highly reflective relativistic mirror of excellent optical quality in experiments? This has remained an open question so far, which has resisted all experimental attempts. In this article, we present the theoretical and numerical efforts that we have carried out to answer this question, starting from the development of the 3D kinetic code WarpX-PICSAR in strong collaboration with the team of Dr. Jean-Luc Vay at Berkeley Lab, up to the very first numerical experiments of CRM designs performed with the code at very large scale. Leveraging on these first results, we show that high-power PW lasers, boosted by a relativistic plasma mirror, can increase SF-QED signatures by orders of magnitude, potentially giving access to new physics at existing laser facilities.
BibTeX:
@article{Vincenti2023,
  author = {Vincenti, Henri and Clark, Thomas and Fedeli, Luca and Martin, Philippe and Sainte-Marie, Antonin and Zaim, Neil},
  title = {Plasma mirrors as a path to the Schwinger limit: theoretical and numerical developments},
  journal = {The European Physical Journal Special Topics},
  year = {2023},
  url = {https://doi.org/10.1140/epjs/s11734-023-00909-2},
  doi = {epjs/s11734-023-00909-}
}
"Absolute calibration up to 20 MeV of an online readout CMOS system suitable to detect high-power lasers accelerated protons"
Burdonov K, Lelièvre R, Forestier-Colleoni P, Ceccotti T, Cuciuc M, Lancia L, Yao W & Fuchs J, Review of Scientific Instruments. Vol. 94(8), (2023).
Abstract: We present the design and absolute calibration of a charged particle online readout CMOS system tailored for high-power laser experiments. This system equips a Thomson parabola spectrometer, which is used at the Apollon petawatt scale laser facility to measure the spectra of protons produced by high-intensity laser-target interactions. The RadEye1 CMOS matrices array detectors are paired with a custom triggering system for image grabbing. This allows us to register the proton and ion signals remotely. The repetition rate is presently 1 shot/min, but the frame grabbing enables the system to be compatible with modern high-power lasers running, e.g., at 1 Hz. We detail here the implementation, in the harsh electromagnetic environment of such interactions, of the system, and its absolute calibration, which was performed for proton energies from 4 to 20 MeV.
BibTeX:
@article{Burdonov2023,
  author = {Burdonov, K. and Lelièvre, R. and Forestier-Colleoni, P. and Ceccotti, T. and Cuciuc, M. and Lancia, L. and Yao, W. and Fuchs, J.},
  title = {Absolute calibration up to 20 MeV of an online readout CMOS system suitable to detect high-power lasers accelerated protons},
  journal = {Review of Scientific Instruments},
  year = {2023},
  volume = {94},
  number = {8},
  url = {https://doi.org/10.1063/5.0150373},
  doi = {10.1063/5.0150373}
}
"De l’ultra-rapide à l’ultra-intense : de nouveaux champs d’études"
Dobosz Dufrenoy S, Ruchon T, Vincenti H, Bresteau D, Monot P, Marroux H, Geneaux R, Hricovini K & Salieres P, Photoniques. (118), pp. 40-45. (2023).
Abstract: Le développement spectaculaire des lasers de puissance ces trente dernières années a ouvert de nouveaux champs d’études : la science attoseconde d’une part, l’optique relativiste d’autre part. Nous illustrons les nouvelles perspectives ouvertes dans divers domaines de la physique, la chimie, la médecine ou la science des matériaux à partir d’études effectuées sur les plateformes ATTOLab et UHI100 du Laboratoire Interactions, Dynamiques et Lasers (LIDYL) du CEA Paris-Saclay.
BibTeX:
@article{dufrenoy2023ultra,
  author = {Dobosz Dufrenoy, Sandrine and Ruchon, Thierry and Vincenti, Henri and Bresteau, David and Monot, Pascal and Marroux, Hugo and Geneaux, Romain and Hricovini, Karol and Salieres, Pascal},
  title = {De l’ultra-rapide à l’ultra-intense : de nouveaux champs d’études},
  journal = {Photoniques},
  year = {2023},
  number = {118},
  pages = {40--45},
  url = {https://doi.org/10.1051/photon/202311840},
  doi = {10.1051/photon/202311840}
}
"Modeling of the driver transverse profile for laser wakefield electron acceleration at APOLLON research facility"
Moulanier I, Dickson LT, Ballage C, Vasilovici O, Gremaud A, Dobosz Dufrénoy S, Delerue N, Bernardi L, Mahjoub A, Cauchois A, Specka A, Massimo F, Maynard G & Cros B, Physics of Plasmas. Vol. 30(5), (2023)
Abstract: The quality of electron bunches accelerated by laser wakefields is highly dependant on the temporal and spatial features of the laser driver. Analysis of experiments performed at APOLLON PW-class laser facility shows that spatial instabilities of the focal spot, such as shot-to-shot pointing fluctuations or asymmetry of the transverse fluence, lead to charge and energy degradation of the accelerated electron bunch. It is shown that PIC simulations can reproduce experimental results with a significantly higher accuracy when the measured laser asymmetries are included in the simulated laser's transverse profile, compared to simulations with ideal, symmetric laser profile. A method based on a modified Gerchberg-Saxton iterative algorithm is used to retrieve the laser electric field from fluence measurements in vacuum in the focal volume, and accurately reproduce experimental results using PIC simulations, leading to simulated electron spectra in close agreement with experimental results, for the accelerated charge, energy distribution, and pointing of the electron beam at the exit of the plasma.
BibTeX:
@article{Moulanier2023,
  author = {Moulanier, I. and Dickson, L. T. and Ballage, C. and Vasilovici, O. and Gremaud, A. and Dobosz Dufrénoy, S. and Delerue, N. and Bernardi, L. and Mahjoub, A. and Cauchois, A. and Specka, A. and Massimo, F. and Maynard, G. and Cros, B.},
  title = {Modeling of the driver transverse profile for laser wakefield electron acceleration at APOLLON research facility},
  journal = {Physics of Plasmas},
  year = {2023},
  volume = {30},
  number = {5},
  url = {https://doi.org/10.1063/5.0142894},
  doi = {10.1063/5.0142894}
}
"Strong-field Quantum Electrodynamics in the extremely intense light of relativistic plasma mirrors"
Sainte-Marie A, Thesis at: Université Paris-Saclay., February, 2023. (2023UPASP021), (2023).
Abstract: In the wake of steady progress in laser technology opening up to an ever wider range of physical configurations, a consistent research community developed around "ultra-high intensity" physics. During the last two decades, these works have uncovered a stable set of physical phenomena and applications, all essentially described by the classical mechanics of fields and particles at relativistic energies. The current situation is however likely to be a turning point, for radically different physical phenomena are expected in last-generation facilities, either planned or under construction, revealing the quantum aspect of particles and fields.Relying on a scheme explicitly designed to foster the ongoing transition, the present thesis fully takes ground in such context. By generating pulses exceeding forecast laser intensities by two to six orders of magnitude, relativistic plasma mirrors could allow entering the quantum-dominated regime of strong-field Quantum Electrodynamics, with fundamental and instrumental implications. Our research was devoted to try and predict some of them explicitly.Remarkably, in the most favorable case the combination of wavelength shortening and pulse amplification in the "harmonics beams" produced by relativistic plasma mirrors results in fields close to the Schwinger critical value, a landmark for the onset of coherent field decay into electron-positron pairs. This entails that quantum processes can occur in harmonics beams both in the presence of matter, or in a vacuum. In this thesis, we will be presenting the expectations derived from a closer study of these different scenarios. The self-interaction of light in a vacuum is studied first, assessing the potential of harmonics beams for a first empirical detection of this long-predicted effect. We will then display the transition from light self-interaction when no matter is there, to prolific pair creation as soon as one particle comes in. This process of pair creation occurs for different types of seed, a Schwinger pair, a dense target, copropagating electron bunches. All three cases were studied and their evolution towards a final state numerically simulated, reveling the possibility to create relativistic quantum electron-positron plasmas with exotic properties, or enter the Ritus-Narozhny regime for the first time, allowing to empirically test strong-field Quantum Electrodynamics even beyond its established theoretical framework.
BibTeX:
@phdthesis{saintemarie:tel-04057676,
  author = {Sainte-Marie, Antonin},
  title = {Strong-field Quantum Electrodynamics in the extremely intense light of relativistic plasma mirrors},
  school = {Université Paris-Saclay},
  year = {2023},
  number = {2023UPASP021},
  url = {https://theses.hal.science/tel-04057676}
}
2022
"Pushing the Frontier in the Design of Laser-Based Electron Accelerators with Groundbreaking Mesh-Refined Particle-In-Cell Simulations on Exascale-Class Supercomputers"
Fedeli L, Huebl A, Boillod-Cerneux F, Clark T, Gott K, Hillairet C, Jaure S, Leblanc A, Lehe R, Myers A, Piechurski C, Sato M, Zaim N, Zhang W, Vay J& Vincenti H, In 2022 SC22: International Conference for High Performance Computing, Networking, Storage and Analysis (SC) (SC). Los Alamitos, CA, USA, nov, 2022. , pp. 25-36. IEEE Computer Society. (2022).
Abstract: (150 word max) We present a first-of-kind meshrefined (MR) massively parallel Particle-In-Cell (PIC) code for kinetic plasma simulations optimized on the Frontier, Fugaku, Summit, and Perlmutter supercomputers. Major innovations, implemented in the WarpX PIC code, include: (i) a three level parallelization strategy that demonstrated performance portability and scaling on millions of A64FX cores and tens of thousands of AMD and Nvidia GPUs (ii) a groundbreaking mesh refinement capability that provides between 1.5* to 4* savings in computing requirements on the science case reported in this paper, (iii) an efficient load balancing strategy between multiple MR levels. The MR PIC code enabled 3D simulations of laser-matter interactions on Frontier, Fugaku, and Summit, which have so far been out of the reach of standard codes. These simulations helped remove a major limitation of compact laserbased electron accelerators, which are promising candidates for next generation high-energy physics experiments and ultra-high dose rate FLASH radiotherapy.
BibTeX:
@inproceedings{,
  author = {L. Fedeli and A. Huebl and F. Boillod-Cerneux and T. Clark and K. Gott and C. Hillairet and S. Jaure and A. Leblanc and R. Lehe and A. Myers and C. Piechurski and M. Sato and N. Zaim and W. Zhang and J. Vay and H. Vincenti},
  title = {Pushing the Frontier in the Design of Laser-Based Electron Accelerators with Groundbreaking Mesh-Refined Particle-In-Cell Simulations on Exascale-Class Supercomputers},
  booktitle = {2022 SC22: International Conference for High Performance Computing, Networking, Storage and Analysis (SC) (SC)},
  publisher = {IEEE Computer Society},
  year = {2022},
  pages = {25-36},
  url = {https://doi.ieeecomputersociety.org/}
}
"Mechanisms to control laser-plasma coupling in laser wakefield electron acceleration"
Dickson LT, Underwood CID, Filippi F, Shalloo RJ, Svensson JB, Guénot D, Svendsen K, Moulanier I, Dobisz Dufrénoy S, Murphy CD, Lopes NC, Rajeev PP, Najmudin Z, Cantono G, Persson A, Lundh O, Maynard G, Streeter MJV & Cros B, Physical Review Accelerators and Beams., Oct, 2022. Vol. 25, pp. 101301. American Physical Society. (2022).
Abstract: Experimental results, supported by precise modeling, demonstrate optimization of a plasma-based injector with intermediate laser pulse energy (< 1J), corresponding to a normalized vector potential a0=2.15, using ionization injection in a tailored plasma density profile. An increase in electron bunch quality and energy is achieved experimentally with the extension of the density downramp at the plasma exit. Optimization of the focal position of the laser pulse in the tailored plasma density profile is shown to efficiently reduce electron bunch angular deviation, leading to a better alignment of the electron bunch with the laser axis. Single peak electron spectra are produced in a previously unexplored regime by combining an early focal position and adaptive optic control of the laser wavefront by optimizing the symmetry of the prefocal laser energy distribution. Experimental results have been validated through particle-in-cell simulations using realistic laser energy, phase distribution, and temporal envelope, allowing for accurate predictions of difficult to model parameters, such as total charge and spatial properties of the electron bunches, opening the way for more accurate modeling for the design of plasma-based accelerators.
BibTeX:
@article{PhysRevAccelBeams.25.101301,
  author = {Dickson, L. T. and Underwood, C. I. D. and Filippi, F. and Shalloo, R. J. and Svensson, J. Björklund and Guénot, D. and Svendsen, K. and Moulanier, I. and Dufrénoy, S. Dobosz and Murphy, C. D. and Lopes, N. C. and Rajeev, P. P. and Najmudin, Z. and Cantono, G. and Persson, A. and Lundh, O. and Maynard, G. and Streeter, M. J. V. and Cros, B.},
  title = {Mechanisms to control laser-plasma coupling in laser wakefield electron acceleration},
  journal = {Phys. Rev. Accel. Beams},
  publisher = {American Physical Society},
  year = {2022},
  volume = {25},
  pages = {101301},
  url = {https://link.aps.org/doi/10.1103/PhysRevAccelBeams.25.101301},
  doi = {10.1103/PhysRevAccelBeams.25.101301}
}
"A hybrid nodal-staggered pseudo-spectral electromagnetic particle-in-cell method with finite-order centering"
Zoni E, Lehe R, Shapoval O, Belkin D, Zaïm N, Fedeli L, Vincenti H & Vay J-L, Computer Physics Communications., October, 2022. Vol. 279, pp. 108457. (2022).
Abstract: Electromagnetic particle-in-cell (PIC) codes are widely used to perform computer simulations of a variety of physical systems, including fusion plasmas, astrophysical plasmas, plasma wakefield particle accelerators, and secondary photon sources driven by ultra-intense lasers. In a PIC code, Maxwell's equations are solved on a grid with a numerical method of choice. This article focuses on pseudo-spectral analytical time-domain (PSATD) algorithms and presents a novel hybrid PSATD PIC scheme that combines the respective advantages of standard nodal and staggered methods. The novelty of the hybrid scheme consists in using finite-order centering of grid quantities between nodal and staggered grids, in order to combine the solution of Maxwell's equations on a staggered grid with the deposition of charges and currents and the gathering of electromagnetic forces on a nodal grid. The correctness and performance of the novel hybrid scheme are assessed by means of numerical tests that employ different classes of PSATD equations in a variety of physical scenarios, ranging from the modeling of electron-positron pair creation in vacuum to the simulation of laser-driven and particle beam-driven plasma wakefield acceleration. It is shown that the novel hybrid scheme offers significant numerical and computational advantages, compared to purely nodal or staggered methods, for all the test cases presented.
BibTeX:
@article{Zoni2022,
  author = {Zoni, Edoardo and Lehe, Remi and Shapoval, Olga and Belkin, Daniel and Zaïm, Neil and Fedeli, Luca and Vincenti, Henri and Vay, Jean-Luc},
  title = {A hybrid nodal-staggered pseudo-spectral electromagnetic particle-in-cell method with finite-order centering},
  journal = {Computer Physics Communications},
  year = {2022},
  volume = {279},
  pages = {108457},
  url = {https://www.sciencedirect.com/science/article/pii/S001046552200176X},
  doi = {10.1016/j.cpc.2022.108457}
}
"Optical coherent manipulation of alkaline-earth circular Rydberg states"
Muni A, Lachaud L, Couto A, Poirier M, Teixeira RC, Raimond J-M, Brune M & Gleyzes S, Nature Physics. Vol. 18, pp. 502-505. (2022).
Abstract: Owing to their large size, Rydberg atoms are promising tools for quantum technologies,
as they exhibit long-range dipole-dipole interactions and strong coupling to external fields.
Recent experiments have demonstrated their appeal for quantum simulation purposes, even though
the relatively short lifetime of optically accessible Rydberg levels imposes limitations.
Long-lived circular Rydberg states may provide a solution. However, the detection of circular
states involves either destructive6 or complex7 measurement techniques. Moreover, so far, alkali
circular states have been manipulated only by microwave fields, which are unable to address
individual atoms. The use of circular states of a different group of atoms, the alkaline-earth
metals, which have an optically active second valence electron, can circumvent these problems.
Here we show how to use the electrostatic coupling between the two valence electrons of
strontium to coherently manipulate a circular Rydberg state with optical pulses. We also exploit
this coupling to map the state of the Rydberg electron onto that of the ionic core. This
experiment opens the way to a state-selective spatially resolved non-destructive detection of
circular states and to the realization of a hybrid optical-microwave platform for quantum
technology.
BibTeX:
@article{Muni2022,
  author = {Muni, Andrea and Lachaud, Léa and Couto, Angelo and Poirier, Michel and Teixeira, Raul Celistrino and Raimond, Jean-Michel and Brune, Michel and Gleyzes, Sébastien},
  title = {Optical coherent manipulation of alkaline-earth circular Rydberg states},
  journal = {Nature Physics},
  year = {2022},
  volume = {18},
  pages = {502--505},
  url = {https://doi.org/10.1038/s41567-022-01519-w},
  doi = {10.1038/s41567-022-01519-w}
}
"PICSAR-QED: a Monte Carlo module to simulate strong-field quantum electrodynamics in particle-in-cell codes for exascale architectures"
Fedeli L, Zaïm N, Sainte-Marie A, Thévenet M, Huebl A, Myers A, Vay J-L & Vincenti H, New Journal of Physics., February, 2022. Vol. 24(2), pp. 025009. IOP Publishing., (2022).
Abstract: Physical scenarios where the electromagnetic fields are so strong that quantum electrodynamics (QED) plays a substantial role are one of the frontiers of contemporary plasma physics research. Investigating those scenarios requires state-of-the-art particle-in-cell (PIC) codes able to run on top high-performance computing (HPC) machines and, at the same time, able to simulate strong-field QED processes. This work presents the PICSAR-QED library, an open-source, portable implementation of a Monte Carlo module designed to provide modern PIC codes with the capability to simulate such processes, and optimized for HPC. Detailed tests and benchmarks are carried out to validate the physical models in PICSAR-QED, to study how numerical parameters affect such models, and to demonstrate its capability to run on different architectures (CPUs and GPUs). Its integration with WarpX, a state-of-the-art PIC code designed to deliver scalable performance on upcoming exascale supercomputers, is also discussed and validated against results from the existing literature.
BibTeX:
@article{Fedeli2022,
  author = {Fedeli, Luca and Zaïm, Neïl and Sainte-Marie, Antonin and Thévenet, Maxence and Huebl, Axel and Myers, Andrew and Vay, Jean-Luc and Vincenti, Henri},
  title = {PICSAR-QED: a Monte Carlo module to simulate strong-field quantum electrodynamics in particle-in-cell codes for exascale architectures},
  journal = {New Journal of Physics},
  publisher = {IOP Publishing},
  year = {2022},
  volume = {24},
  number = {2},
  pages = {025009},
  url = {http://dx.doi.org/10.1088/1367-2630/ac4ef1}
}
"Sub-laser-cycle control of relativistic plasma mirrors"
Chopineau L, Blaclard G, Denoeud A, Vincenti H, Quéré F & Haessler S, "Sub-laser-cycle control of relativistic plasma mirrors", Physical Review Research., Mar, 2022. Vol. 4, pp. L012030. American Physical Society. (2022).
Abstract: We present measurements of high-order harmonics and relativistic electrons emitted into the vacuum from a plasma mirror driven by temporally shaped ultraintense laser wave forms, produced by collinearly combining the main laser field with its second harmonic. We experimentally show how these observables are influenced by the phase delay between these two frequencies at the attosecond timescale, and relate these observations to the underlying physics through an advanced analysis of 1D/2D particle-in-cell simulations. These results demonstrate that subcycle shaping of the driving laser field provides fine control on the properties of the relativistic electron bunches responsible for harmonic and particle emission from plasma mirrors.
BibTeX:
@article{PhysRevResearch.4.L012030,
  author = {Chopineau, L. and Blaclard, G. and Denoeud, A. and Vincenti, H. and Quéré, F. and Haessler, S.},
  title = {Sub-laser-cycle control of relativistic plasma mirrors},
  journal = {Phys. Rev. Research},
  publisher = {American Physical Society},
  year = {2022},
  volume = {4},
  pages = {L012030},
  url = {https://link.aps.org/doi/10.1103/PhysRevResearch.4.L012030},
  doi = {10.1103/PhysRevResearch.4.L012030}
}
"Survey of spatio-temporal couplings throughout high-power ultrashort lasers"
Jeandet A, Jolly SW, Borot A, Bussière B, Dumont P, Gautier J, Gobert O, Goddet J-P, Gonsalves A, Irman A, Leemans WP, Lopez-Martens R, Mennerat G, Nakamura K, Ouillé M, Pariente G, Pittman M, Püschel T, Sanson F, Sylla F, Thaury C, Zeil K & Quéré F, Optics Express., January, 2022. Vol. 30(3), pp. 3262-3288. Optica Publishing Group. (2022).
Abstract: The investigation of spatio-temporal couplings (STCs) of broadband light beams is becoming a key topic for the optimization as well as applications of ultrashort laser systems. This calls for accurate measurements of STCs. Yet, it is only recently that such complete spatio-temporal or spatio-spectral characterization has become possible, and it has so far mostly been implemented at the output of the laser systems, where experiments take place. In this survey, we present for the first time STC measurements at different stages of a collection of high-power ultrashort laser systems, all based on the chirped-pulse amplification (CPA) technique, but with very different output characteristics. This measurement campaign reveals spatio-temporal effects with various sources, and motivates the expanded use of STC characterization throughout CPA laser chains, as well as in a wider range of types of ultrafast laser systems. In this way knowledge will be gained not only about potential defects, but also about the fundamental dynamics and operating regimes of advanced ultrashort laser systems.
BibTeX:
@article{Jeandet2022,
  author = {Jeandet, Antoine and Jolly, Spencer W. and Borot, Antonin and Bussière, Benoît and Dumont, Paul and Gautier, Julien and Gobert, Olivier and Goddet, Jean-Philippe and Gonsalves, Anthony and Irman, Arie and Leemans, Wim P. and Lopez-Martens, Rodrigo and Mennerat, Gabriel and Nakamura, Kei and Ouillé, Marie and Pariente, Gustave and Pittman, Moana and Püschel, Thomas and Sanson, Fabrice and Sylla, François and Thaury, Cédric and Zeil, Karl and Quéré, Fabien},
  title = {Survey of spatio-temporal couplings throughout high-power ultrashort lasers},
  journal = {Opt. Express},
  publisher = {Optica Publishing Group},
  year = {2022},
  volume = {30},
  number = {3},
  pages = {3262--3288},
  url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-30-3-3262},
  doi = {10.1364/OE.444564}
}
2021
"Exact expressions for the number of levels in single-j orbits for three, four, and five fermions"
Poirier M & Pain J-C, "Exact expressions for the number of levels in single-j orbits for three, four, and five fermions", Physical Review C., Dec, 2021. Vol. 104, pp. 064324. American Physical Society, (2021).
Abstract: We propose closed-form expressions of the distributions of magnetic quantum number M and total angular momentum J for three and four fermions in single-j orbits. The latter formulas consist of polynomials with coefficients satisfying congruence properties. Such results, derived using doubly recursive relations over j and the number of fermions, enable us to deduce explicit expressions for the total number of levels in the case of three-, four-, and five-fermion systems. We present applications of these formulas, such as sum rules for six-j and nine-j symbols, obtained from the connection with fractional-parentage coefficients, an alternative proof of the Ginocchio-Haxton relation, or cancellation properties of the number of levels with a given angular momentum.
BibTeX:
@article{Poirier2021a,
  author = {Poirier, Michel and Pain, Jean-Christophe},
  title = {Exact expressions for the number of levels in single-j orbits for three, four, and five fermions},
  journal = {Phys. Rev. C},
  publisher = {American Physical Society},
  year = {2021},
  volume = {104},
  pages = {064324},
  url = {https://link.aps.org/doi/10.1103/PhysRevC.104.064324},
  doi = {10.1103/PhysRevC.104.064324}
}
"Characterization and performance of the Apollon short-focal-area facility following its commissioning at 1 PW level"
Burdonov K, Fazzini A, Lelasseux V, Albrecht J, Antici P, Ayoul Y, Beluze A, Cavanna D, Ceccotti T, Chabanis M, Chaleil A, Chen SN, Chen Z, Consoli F, Cuciuc M, Davoine X, Delaneau JP, d’Humières E, Dubois J-L, Evrard C, Filippov E, Freneaux A, Forestier-Colleoni P, Gremillet L, Horny V, Lancia L, Lecherbourg L, Lebas N, Leblanc A, Ma W, Martin L, Negoita F, Paillard J-L, Papadopoulos D, Perez F, Pikuz S, Qi G, Quéré F, Ranc L, Söderström P-A, Scisciò M, Sun S, Vallières S, Wang P, Yao W, Mathieu F, Audebert P & Fuchs J, Matter and Radiation at Extremes., November, 2021. Vol. 6(6), pp. 064402. American Institute of Physics, (2021).
Abstract: We present the results of the first commissioning phase of the short-focal-length area of the Apollon laser facility (located in Saclay, France), which was performed with the first available laser beam (F2), scaled to a nominal power of 1 PW. Under the conditions that were tested, this beam delivered on-target pulses of 10 J average energy and 24 fs duration. Several diagnostics were fielded to assess the performance of the facility. The on-target focal spot and its spatial stability, the temporal intensity profile prior to the main pulse, and the resulting density gradient formed at the irradiated side of solid targets have been thoroughly characterized, with the goal of helping users design future experiments. Emissions of energetic electrons, ions, and electromagnetic radiation were recorded, showing good laser-to-target coupling efficiency and an overall performance comparable to that of similar international facilities. This will be followed in 2022 by a further commissioning stage at the multi-petawatt level.
BibTeX:
@article{Burdonov2021,
  author = {Burdonov, K. and Fazzini, A. and Lelasseux, V. and Albrecht, J. and Antici, P. and Ayoul, Y. and Beluze, A. and Cavanna, D. and Ceccotti, T. and Chabanis, M. and Chaleil, A. and Chen, S. N. and Chen, Z. and Consoli, F. and Cuciuc, M. and Davoine, X. and Delaneau, J. P. and d’Humières, E. and Dubois, J.-L. and Evrard, C. and Filippov, E. and Freneaux, A. and Forestier-Colleoni, P. and Gremillet, L. and Horny, V. and Lancia, L. and Lecherbourg, L. and Lebas, N. and Leblanc, A. and Ma, W. and Martin, L. and Negoita, F. and Paillard, J.-L. and Papadopoulos, D. and Perez, F. and Pikuz, S. and Qi, G. and Quéré, F. and Ranc, L. and Söderström, P.-A. and Scisciò, M. and Sun, S. and Vallières, S. and Wang, P. and Yao, W. and Mathieu, F. and Audebert, P. and Fuchs, J.},
  title = {Characterization and performance of the Apollon short-focal-area facility following its commissioning at 1 PW level},
  journal = {Matter and Radiation at Extremes},
  publisher = {American Institute of Physics},
  year = {2021},
  volume = {6},
  number = {6},
  pages = {064402},
  url = {https://doi.org/10.1063/5.0065138},
  doi = {10.1063/5.0065138}
}
"Porting WarpX to GPU-accelerated platforms"
Myers A, Almgren A, Amorim LD, Bell J, Fedeli L, Ge L, Gott K, Grote DP, Hogan M, Huebl A, Jambunathan R, Lehe R, Ng C, Rowan M, Shapoval O, Thévenet M, Vay J-L, Vincenti H, Yang E, Zaïm N, Zhang W, Zhao Y & Zoni E, Parallel Computing., December, 2021. Vol. 108, pp. 102833, (2021).
Abstract: WarpX is a general purpose electromagnetic particle-in-cell code that was originally designed to run on many-core CPU architectures. We describe the strategy, based on the AMReX library, followed to allow WarpX to use the GPU-accelerated nodes on OLCF’s Summit supercomputer, a strategy we believe will extend to the upcoming machines Frontier and Aurora. We summarize the challenges encountered, lessons learned, and give current performance results on a series of relevant benchmark problems.
BibTeX:
@article{Myers2021,
  author = {Myers, A. and Almgren, A. and Amorim, L. D. and Bell, J. and Fedeli, L. and Ge, L. and Gott, K. and Grote, D. P. and Hogan, M. and Huebl, A. and Jambunathan, R. and Lehe, R. and Ng, C. and Rowan, M. and Shapoval, O. and Thévenet, M. and Vay, J.-L. and Vincenti, H. and Yang, E. and Zaïm, N. and Zhang, W. and Zhao, Y. and Zoni, E.},
  title = {Porting WarpX to GPU-accelerated platforms},
  journal = {Parallel Computing},
  year = {2021},
  volume = {108},
  pages = {102833},
  url = {https://www.sciencedirect.com/science/article/pii/S0167819121000818},
  doi = {10.1016/j.parco.2021.102833}
}
"Probing Strong-Field QED with Doppler-Boosted Petawatt-Class Lasers"
Fedeli L, Sainte-Marie A, Zaim N, Thévenet M, Vay JL, Myers A, Quéré F & Vincenti H, Physical Review Letters., Sep, 2021. Vol. 127, pp. 114801. American Physical Society, (2021).
Abstract: We propose a scheme to explore regimes of strong-field quantum electrodynamics (SF QED) otherwise unattainable with the currently available laser technology. The scheme relies on relativistic plasma mirrors curved by radiation pressure to boost the intensity of petawatt-class laser pulses by Doppler effect and focus them to extreme field intensities. We show that very clear SF QED signatures could be observed by placing a secondary target where the boosted beam is focused.
BibTeX:
@article{PhysRevLett.127.114801,
  author = {Fedeli, L. and Sainte-Marie, A. and Zaim, N. and Thévenet, M. and Vay, J. L. and Myers, A. and Quéré, F. and Vincenti, H.},
  title = {Probing Strong-Field QED with Doppler-Boosted Petawatt-Class Lasers},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2021},
  volume = {127},
  pages = {114801},
  url = {https://link.aps.org/doi/10.1103/PhysRevLett.127.114801},
  doi = {10.1103/PhysRevLett.127.114801}
}
"Distribution of the total angular momentum in relativistic configurations"
Poirier M & Pain J-C, Journal of Physics B: Atomic, Molecular and Optical Physics.., jul, 2021. IOP Publishing, vol 54, page 145006. (2021).
Abstract: This paper is devoted to the analysis of the distribution of the total angular momentum in a relativistic configuration. Using cumulants and generating function formalism this analysis can be reduced to the study of individual subshells with N equivalent electrons of momentum j. An expression as a nth-derivative is provided for the generating function of the J distribution and efficient recurrence relations are established. It is shown that this distribution may be represented by a Gram-Charlier-like series which is derived from the corresponding series for the magnetic quantum number distribution. The numerical efficiency of this expansion is fair when the configuration consists of several subshells, while the accuracy is less good when only one subshell is involved. An analytical expression is given for the odd-order momenta while the even-order ones are expressed as a series which provides an acceptable accuracy though being not convergent. Such expressions may be used to obtain approximate values for the number of transitions in a spin-orbit split array: it is shown that the approximation is often efficient when few terms are kept, while some complex cases require to include a large number of terms.
BibTeX:
@article{Poirier_2021,
  author = {Michel Poirier and Jean-Christophe Pain},
  title = {Distribution of the total angular momentum in relativistic configurations},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  publisher = {IOP Publishing},
  year = {2021},
  page = {145006},
  vol  = {54},
  url = {https://doi.org/10.1088/1361-6455/ac17cb},
  doi = {10.1088/1361-6455/ac17cb}
}
"Angular momentum distribution in a relativistic configuration: magnetic quantum number analysis"
Poirier M & Pain J-C, Journal of Physics B: Atomic, Molecular and Optical Physics., jul, 2021. Vol. 54(14), pp. 145002. IOP Publishing. (2021).
Abstract: This paper is devoted to the analysis of the distribution of the total magnetic quantum number M in a relativistic subshell with N equivalent electrons of momentum j. This distribution is analyzed through its cumulants and through their generating function, for which an analytical expression is provided. This function also allows us to get the values of the cumulants at any order. Such values are useful to obtain the moments at various orders. Since the cumulants of the distinct subshells are additive this study directly applies to any relativistic configuration. Recursion relations on the generating function are given. It is shown that the generating function of the magnetic quantum number distribution may be expressed as an nth derivative of a polynomial. This leads to recurrence relations for this distribution which are very efficient even in the case of large j or N. The magnetic quantum number distribution is numerically studied using the Gram-Charlier and Edgeworth expansions. The inclusion of high-order terms may improve the accuracy of the Gram-Charlier representation for instance when a small and a large angular momenta coexist in the same configuration. However such series does not exhibit convergence when high orders are considered and the account for the first two terms often provides a fair approximation of the magnetic quantum number distribution. The Edgeworth series offers an interesting alternative though this expansion is also divergent and of asymptotic nature.
BibTeX:
@article{Poirier2021,
  author = {Michel Poirier and Jean-Christophe Pain},
  title = {Angular momentum distribution in a relativistic configuration: magnetic quantum number analysis},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  publisher = {IOP Publishing},
  year = {2021},
  volume = {54},
  number = {14},
  pages = {145002},
  url = {https://doi.org/10.1088/1361-6455/ac10f9},
  doi = {10.1088/1361-6455/ac10f9}
}
"Spatio-temporal characterization of attosecond pulses from plasma mirrors"
Chopineau L, Denoeud A, Leblanc A, Porat E, Martin P, Vincenti H & Quéré F, Nature Physics., June, 2021.
Abstract: Reaching light intensities above 1025 W cm-2 and up to the Schwinger limit of order 1029 W cm-2 would enable the testing of fundamental predictions of quantum electrodynamics. A promising--yet challenging--approach to achieve such extreme fields consists in reflecting a high-power femtosecond laser pulse off a curved relativistic mirror. This enhances the intensity of the reflected beam by simultaneously compressing it in time down to the attosecond range, and focusing it to submicrometre focal spots. Here we show that such curved relativistic mirrors can be produced when an ultra-intense laser pulse ionizes a solid target and creates a dense plasma that specularly reflects the incident light. This is evidenced by measuring the temporal and spatial effects induced on the reflected beam by this so-called plasma mirror. The all-optical measurement technique demonstrated here will be instrumental for the use of relativistic plasma mirrors with the upcoming generation of petawatt lasers that recently reached intensities of 5 x 1022 W cm-2, and therefore constitutes a viable experimental path to the Schwinger limit.
BibTeX:
@article{Chopineau2021,
  author = {Chopineau, Ludovic and Denoeud, Adrien and Leblanc, Adrien and Porat, Elkana and Martin, Philippe and Vincenti, Henri and Quéré, Fabien},
  title = {Spatio-temporal characterization of attosecond pulses from plasma mirrors},
  journal = {Nature Physics},
  year = {2021},
  url = {https://doi.org/10.1038/s41567-021-01253-9},
  doi = {10.1038/s41567-021-01253-9}
}
"Modeling of a chain of three plasma accelerator stages with the WarpX electromagnetic PIC code on GPUs"
Vay J-L, Huebl A, Almgren A, Amorim LD, Bell J, Fedeli L, Ge L, Gott K, Grote DP, Hogan M, Jambunathan R, Lehe R, Myers A, Ng C, Rowan M, Shapoval O, Thévenet M, Vincenti H, Yang E, Zaïm N, Zhang W, Zhao Y & Zoni E, Physics of Plasmas., February, 2021. Vol. 28(2), pp. 023105. American Institute of Physics, (2021).
Abstract: The fully electromagnetic particle-in-cell code WarpX is being developed by a team of the U.S. DOE Exascale Computing Project (with additional non-U.S. collaborators on part of the code) to enable the modeling of chains of tens to hundreds of plasma accelerator stages on exascale supercomputers, for future collider designs. The code is combining the latest algorithmic advances (e.g., Lorentz boosted frame and pseudo-spectral Maxwell solvers) with mesh refinement and runs on the latest computer processing unit and graphical processing unit (GPU) architectures. In this paper, we summarize the strategy that was adopted to port WarpX to GPUs, report on the weak parallel scaling of the pseudo-spectral electromagnetic solver, and then present solutions for decreasing the time spent in data exchanges from guard regions between subdomains. In Sec. IV, we demonstrate the simulations of a chain of three consecutive multi-GeV laser-driven plasma accelerator stages.
BibTeX:
@article{Vay2021,
  author = {Vay, J.-L. and Huebl, A. and Almgren, A. and Amorim, L. D. and Bell, J. and Fedeli, L. and Ge, L. and Gott, K. and Grote, D. P. and Hogan, M. and Jambunathan, R. and Lehe, R. and Myers, A. and Ng, C. and Rowan, M. and Shapoval, O. and Thévenet, M. and Vincenti, H. and Yang, E. and Zaïm, N. and Zhang, W. and Zhao, Y. and Zoni, E.},
  title = {Modeling of a chain of three plasma accelerator stages with the WarpX electromagnetic PIC code on GPUs},
  journal = {Physics of Plasmas},
  publisher = {American Institute of Physics},
  year = {2021},
  volume = {28},
  number = {2},
  pages = {023105},
  url = {https://aip.scitation.org/doi/abs/10.1063/5.0028512},
  doi = {10.1063/5.0028512}
}
"Reflecting petawatt lasers off relativistic plasma mirrors: a realistic path to the Schwinger limit"
Quéré F & Vincenti H, High Power Laser Science and Engineering. Vol. 9, pp. e6. Cambridge University Press, (2021).
Abstract: The quantum vacuum plays a central role in physics. Quantum electrodynamics (QED) predicts that the properties of the fermionic quantum vacuum can be probed by extremely large electromagnetic fields. The typical field amplitudes required correspond to the onset of the ‘optical breakdown’ of this vacuum, expected at light intensities >4.7×1029 W/cm2. Approaching this ‘Schwinger limit’ would enable testing of major but still unverified predictions of QED. Yet, the Schwinger limit is seven orders of magnitude above the present record in light intensity achieved by high-power lasers. To close this considerable gap, a promising paradigm consists of reflecting these laser beams off a mirror in relativistic motion, to induce a Doppler effect that compresses the light pulse in time down to the attosecond range and converts it to shorter wavelengths, which can then be focused much more tightly than the initial laser light. However, this faces a major experimental hurdle: how to generate such relativistic mirrors? In this article, we explain how this challenge could nowadays be tackled by using so-called ‘relativistic plasma mirrors’. We argue that approaching the Schwinger limit in the coming years by applying this scheme to the latest generation of petawatt-class lasers is a challenging but realistic objective.
BibTeX:
@article{Quere2021,
  author = {Quéré, Fabien and Vincenti, Henri},
  title = {Reflecting petawatt lasers off relativistic plasma mirrors: a realistic path to the Schwinger limit},
  journal = {High Power Laser Science and Engineering},
  publisher = {Cambridge University Press},
  year = {2021},
  volume = {9},
  pages = {e6},
  edition = {2021/01/19},
  url = {https://www.cambridge.org/core/article/reflecting-petawatt-lasers-off-relativistic-plasma-mirrors-a-realistic-path-to-the-schwinger-limit/40D400C997846AE24EA48411BF9222E0},
  doi = {10.1017/hpl.2020.46}
}
2020
"Spatio-spectral metrology at focus of ultrashort lasers: a phase-retrieval approach: erratum"
Borot A & Quéré F, Optics Express., September, 2020. Vol. 28(20), pp. 30233-30233. OSA, (2020).
Abstract: This is an erratum on the manuscript entitled 'Spatio-spectral metrology at focus of ultrashort lasers: a phase-retrieval approac', by A. Borot and F. Quéré [Opt. Express26, 26444 (2018)].
BibTeX:
@article{Borot2020,
  author = {Borot, A. and Quéré, F.},
  title = {Spatio-spectral metrology at focus of ultrashort lasers: a phase-retrieval approach: erratum},
  journal = {Opt. Express},
  publisher = {OSA},
  year = {2020},
  volume = {28},
  number = {20},
  pages = {30233--30233},
  url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-28-20-30233}
}
"Ultra-High Intense Laser on Dense Plasmas : from Periodic to Chaotic Dynamics"
Blaclard G . Thesis at: Université Paris-Saclay., July, 2020. (2020UPASS133), (2020).
Abstract: The advent of high power femtosecond lasers has paved the way to a promising and still largely unexplored branch of physics called Ultra-High Intensity physics (UHI). Once such a laser is focused on a solid target, the laser intensity I₀ can reach values as large as 10¹⁸⁻²⁰ W.cm⁻², for which matter is fully ionized. The plasma thus formed expands towards vacuum on a spatial scale characterized by a quantity Lg called the density gradient scale length. When Lg << λ₀ (laser wavelength), the dense plasma therefore acts as an optical mirror that specularly reflects the incident light: it is a plasma mirror. This remarkable physical system can be used in many scientific applications as compact source of high-energy and high-charge particle beams (electrons, ions) or bright source of radiations ranging from extreme ultraviolet-rays to X-rays through high harmonic generation processes. In order to finely control these sources, it is required to properly identify the different coupling mechanisms between light and matter at play during the interaction. In this manuscript, this has been made possible by performing accurate Particle-In-Cell (PIC) simulations with the WARP+PXR code. This recently developed code advances Maxwell’s equations in Fourier space, which proves to correctly model harmonic/electron emissions that standard codes fail to accurate describe even at high resolution. Based on WARP+PXR PIC simulations, we investigate the influence of Lg on the experimentally observed emission of light and particles, when a high-power laser pulse (I₀ = 10¹⁹ W.cm⁻²) reflects off a dense plasma. Our study reveals an unambiguous transition from a temporally periodic mechanism to a chaotic process as the interface becomes smoother. In particular, the latter mechanism, named stochastic heating, is fully characterized as well as its domain of validity in terms of laser-plasma parameters. In this regime, electrons in the underdense part of the gradient are exposed to the standing wave formed in front of the overcritical part of the plasma by superposition of incidence and reflected beams. While evolving in the two waves, electrons behave chaotically and absorb an important fraction of the laser energy. The nature of the interaction is revealed by reducing the equations of motion of particles in two waves to physical systems, such Kapitza’s pendulum, well-known to exhibit chaos. That correspondence gives deep physical intuitions on how electrons behave in different laser configurations, which allows us to predict major features of stochastic heating.
BibTeX:
@phdthesis{blaclard:tel-03131619,
  author = {Blaclard, Guillaume},
  title = {Ultra-High Intense Laser on Dense Plasmas : from Periodic to Chaotic Dynamics},
  school = {Université Paris-Saclay},
  year = {2020},
  number = {2020UPASS133},
  url = {https://theses.hal.science/tel-03131619}
}
"Analytical and numerical expressions for the number of atomic configurations contained in a supershell"
Pain J-C & Poirier M, Journal of Physics B: Atomic, Molecular and Optical Physics. Vol. 53, pp. 115002. IOP Publishing, (2020).
Abstract: We present three explicit formulas for the number of electronic configurations in an atom, i.e. the number of ways to distribute Q electrons in N subshells of respective degeneracies g 1, g 2, ..., g N. The new expressions are obtained using the generating-function formalism. The first one contains sums involving multinomial coefficients. The second one relies on the idea of gathering subshells having the same degeneracy. A third one also collects subshells with the same degeneracy and leads to the definition of a two-variable generating function, allowing the derivation of recursion relations. All these formulas can be expressed as summations of products of binomial coefficients. Concerning the distribution of population on N distinct subshells of a given degeneracy g, analytical expressions for the first moments of this distribution are given. The general case of subshells with any degeneracy is analysed through the computation of cumulants. A fairly simple expression for the cumulants at any order is provided, as well as the cumulant generating function. Using Gram-Charlier expansion, simple approximations of the analysed distribution in terms of a normal distribution multiplied by a sum of Hermite polynomials are given. These Gram-Charlier expansions are tested at various orders and for various examples of supershells. When few terms are kept they are shown to provide simple and efficient approximations of the distribution, even for moderate values of the number of subshells, though such expansions diverge when higher order terms are accounted for. The Edgeworth expansion has also been tested. Its accuracy is equivalent to the Gram-Charlier accuracy when few terms are kept, but it is much more rapidly divergent when the truncation order increases. While this analysis is illustrated by examples in atomic supershells it also applies to more general combinatorial problems such as fermion distributions.
BibTeX:
@article{Pain2020,
  author = {Jean-Christophe Pain and Michel Poirier},
  title = {Analytical and numerical expressions for the number of atomic configurations contained in a supershell},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  publisher = {IOP Publishing},
  year = {2020},
  volume = {53},
  pages = {115002},
  url = {https://doi.org/10.1088/1361-6455/ab81ea},
  doi = {10.1088/1361-6455/ab81ea}
}
"Controlling the velocity of a femtosecond laser pulse using refractive lenses"
Jolly SW, Gobert O, Jeandet A & Quéré F, Optics Express., February, 2020. Vol. 28(4), pp. 4888-4897. OSA, (2020).
Abstract: The combination of temporal chirp with a simple chromatic aberration known as longitudinal chromatism leads to extensive control over the velocity of laser intensity in the focal region of an ultrashort laser beam. We present the first implementation of this effect on a femtosecond laser. We demonstrate that by using a specially designed and characterized lens doublet to induce longitudinal chromatism, this velocity control can be implemented independent of the parameters of the focusing optic, thus allowing for great flexibility in experimental applications. Finally, we explain and demonstrate how this spatiotemporal phenomenon evolves when imaging the ultrashort pulse focus with a magnification different from unity.
BibTeX:
@article{Jolly2020,
  author = {Jolly, Spencer W. and Gobert, Olivier and Jeandet, Antoine and Quéré, Fabien},
  title = {Controlling the velocity of a femtosecond laser pulse using refractive lenses},
  journal = {Opt. Express},
  publisher = {OSA},
  year = {2020},
  volume = {28},
  number = {4},
  pages = {4888--4897},
  url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-28-4-4888},
  doi = {10.1364/OE.384512}
}
"Interaction of Ultraintense Radially-Polarized Laser Pulses with Plasma Mirrors"
Zaïm N, Guénot D, Chopineau L, Denoeud A, Lundh O, Vincenti H, Quéré F & Faure J, Physical Review X., Dec, 2020. Vol. 10, pp. 041064. American Physical Society, (2020).
Abstract: We present experimental results of vacuum laser acceleration (VLA) of electrons using radially polarized laser pulses interacting with a plasma mirror. Tightly focused, radially polarized laser pulses have been proposed for electron acceleration because of their strong longitudinal electric field, making them ideal for VLA. However, experimental results have been limited until now because injecting electrons into the laser field has remained a considerable challenge. Here, we demonstrate experimentally that using a plasma mirror as an injector solves this problem and permits us to inject electrons at the ideal phase of the laser, resulting in the acceleration of electrons along the laser propagation direction while reducing the electron beam divergence compared to the linear polarization case. We obtain electron bunches with few-MeV energies and a 200-pC charge, thus demonstrating, for the first time, electron acceleration to relativistic energies using a radially polarized laser. High-harmonic generation from the plasma surface is also measured, and it provides additional insight into the injection of electrons into the laser field upon its reflection on the plasma mirror. Detailed comparisons between experimental results and full 3D simulations unravel the complex physics of electron injection and acceleration in this new regime: We find that electrons are injected into the radially polarized pulse in the form of two spatially separated bunches emitted from the p-polarized regions of the focus. Finally, we leverage on the insight brought by this study to propose and validate a more optimal experimental configuration that can lead to extremely peaked electron angular distributions and higher energy beams.
BibTeX:
@article{PhysRevX.10.041064,
  author = {Zaïm, N. and Guénot, D. and Chopineau, L. and Denoeud, A. and Lundh, O. and Vincenti, H. and Quéré, F. and Faure, J.},
  title = {Interaction of Ultraintense Radially-Polarized Laser Pulses with Plasma Mirrors},
  journal = {Phys. Rev. X},
  publisher = {American Physical Society},
  year = {2020},
  volume = {10},
  pages = {041064},
  url = {https://link.aps.org/doi/10.1103/PhysRevX.10.041064},
  doi = {10.1103/PhysRevX.10.041064}
}
"Temporal metrology for advanced ultrashort XUV sources"
Sinyakova T, Bomme C, Bourassin-Bouchet C, Chopineau L, Cubaynes D, Dakroub L, Garcia G, Pandey A, Papagiannouli E, Guilbaud O, Quéré F & Klisnick A, Journal of Physics: Conference Series., January, 2020. Vol. 1412, pp. 072022. IOP Publishing, (2020)
Abstract: A new VMI spectrometer has been developed in order to enable the single-shot characterization of different ultrashort XUV sources through laser-dressed photoionization. The instrument has been commissioned with a plasma-based XUV laser and, then, implemented on a high harmonics source based on a plasma mirror.
BibTeX:
@article{Sinyakova2020,
  author = {Sinyakova, T. and Bomme, C. and Bourassin-Bouchet, C. and Chopineau, L. and Cubaynes, D. and Dakroub, L. and Garcia, G. and Pandey, A. and Papagiannouli, E. and Guilbaud, O. and Quéré, F. and Klisnick, A.},
  title = {Temporal metrology for advanced ultrashort XUV sources},
  journal = {Journal of Physics: Conference Series},
  publisher = {IOP Publishing},
  year = {2020},
  volume = {1412},
  pages = {072022},
  url = {http://dx.doi.org/10.1088/1742-6596/1412/7/072022},
  doi = {10.1088/1742-6596/1412/7/072022}
}
"Techniques to generate intense isolated attosecond pulses from relativistic plasma mirrors"
Kallala H, Quéré F & Vincenti H, Physical Review Research., Oct, 2020. Vol. 2, pp. 043007. American Physical Society, (2020).
Abstract: Doppler harmonic generation of a high-power laser on a relativistic plasma mirror is a promising path to produce bright attosecond light bursts. However, a major challenge has been to find a way to generate isolated attosecond pulses, better suited to timed-resolved experiments, rather than trains of pulses. A promising technique is the attosecond lighthouse effect, which consists in imprinting different propagation directions to successive attosecond pulses of the train, and then spatially filtering one pulse in the far field. However, in the relativistic regime, plasma mirrors get curved by the radiation pressure of the incident laser and thus focus the generated harmonic beams. This increases the harmonic beam divergence and makes it difficult to separate the attosecond pulses angularly. In this article, we propose two novel techniques readily applicable in experiments to significantly reduce the divergence of Doppler harmonics, and achieve the generation of isolated attosecond pulses from the lighthouse effect without requiring few-cycle laser pulses. Their validity is demonstrated using state-of-the-art simulations, which show that isolated attosecond pulses with 10 TW peak power in the XUV range can be generated with PW-class lasers. These techniques can equally be applied to other generation mechanisms to alleviate the constraints on the duration on the laser pulses needed to generate isolated attosecond pulses.
BibTeX:
@article{PhysRevResearch.2.043007,
  author = {Kallala, H. and Quéré, F. and Vincenti, H.},
  title = {Techniques to generate intense isolated attosecond pulses from relativistic plasma mirrors},
  journal = {Phys. Rev. Research},
  publisher = {American Physical Society},
  year = {2020},
  volume = {2},
  pages = {043007},
  url = {https://link.aps.org/doi/10.1103/PhysRevResearch.2.043007},
  doi = {10.1103/PhysRevResearch.2.043007}
}
"Quantifying Decoherence in Attosecond Metrology"
Bourassin-Bouchet C, Barreau L, Gruson V, Hergott J-F, Quéré F, Salières P and Ruchon T, Physical Review X., Aug, 2020. Vol. 10, pp. 031048. American Physical Society, (2020)
Abstract: Laser-dressed photoemission spectroscopy has established itself as the gold standard of attosecond temporal metrology. In this technique, the attosecond structure of an extreme-ultraviolet pulse is retrieved from the wave function of the electron wave packet released during photoionization. Here, we show that this electron wave packet should rather be described using the density matrix formalism, thus allowing one to account for all processes that can affect its coherence, from the attosecond pulse generation to the photoemission and the measurement processes. Using this approach, we reconstruct experimentally a partially coherent electron wave packet with a purity of 0.11 (1 for full coherence). Comparison with theoretical models then allows us to identify the origins of this decoherence and to overcome several limitations such as beam-line instabilities or spectrometer resolution. Furthermore, we show numerically how this method gives access to the coherence and eigencomponents of complex photoelectron wave packets. It thus goes beyond the current measurement of photoionization time delays and provides a general framework for the analysis and understanding of complex photoemission processes.
BibTeX:
@article{PhysRevX.10.031048,
  author = {Bourassin-Bouchet, C. and Barreau, L. and Gruson, V. and Hergott, J.-F. and Quéré, F. and Salières, P. and Ruchon, T.},
  title = {Quantifying Decoherence in Attosecond Metrology},
  journal = {Phys. Rev. X},
  publisher = {American Physical Society},
  year = {2020},
  volume = {10},
  pages = {031048},
  url = {https://link.aps.org/doi/10.1103/PhysRevX.10.031048},
  doi = {10.1103/PhysRevX.10.031048}
}
"Non-invasive characterisation of a laser-driven positron beam"
Alejo A, Samarin GM, Warwick J, McCluskey C, Cantono G, Ceccotti T, Dobosz Dufrénoy S, Monot P & Sarri G, Plasma Physics and Controlled Fusion., April, 2020. Vol. 62(5), pp. 055013. IOP Publishing, (2020).
Abstract: We report on an indirect and non-invasive method to simultaneously characterise the energy-dependent emittance and source size of ultra-relativistic positron beams generated during the propagation of a laser-wakefield accelerated electron beam through a high-Z converter target. The strong correlation of the geometrical emittance of the positrons with that of the scattered electrons allows the former to be inferred, with high accuracy, from monitoring the latter. The technique has been tested in a proof-of-principle experiment where, for 100 MeV positrons, we infer geometrical emittances and source sizes of the order of 3 m and 150 m, respectively. This is consistent with the numerically predicted possibility of achieving sub-m geometrical emittances and micron-scale source sizes at the GeV level.
BibTeX:
@article{Alejo2020,
  author = {Alejo, A. and Samarin, G. M. and Warwick, J. and McCluskey, C. and Cantono, G. and Ceccotti, T. and Dobosz Dufrénoy, S. and Monot, P. and Sarri, G.},
  title = {Non-invasive characterisation of a laser-driven positron beam},
  journal = {Plasma Physics and Controlled Fusion},
  publisher = {IOP Publishing},
  year = {2020},
  volume = {62},
  number = {5},
  pages = {055013},
  url = {http://dx.doi.org/10.1088/1361-6587/ab7e81},
  doi = {10.1088/1361-6587/ab7e81}
}
"Multipass cells: 1D numerical model and investigation of spatio-spectral couplings at high nonlinearity"
Daher N, Guichard F, Jolly SW, Délen X, Quéré F, Hanna M & Georges P, Journal of the Optical Society of America B, April, 2020. Vol. 37(4), pp. 993-999. OSA, (2020).
Abstract: Multipass cells (MPCs) are used nowadays as nonlinear tools to perform spectral broadening and temporal manipulation of laser pulses while maintaining a good spatial quality and spatio-spectral homogeneity. However, intensive 3D nonlinear spatio-temporal simulations are required to fully capture the physics associated with pulse propagation inside these systems. In addition, the limitations of such a scheme are still under investigation. In this study, we first establish a 1D model as a useful design tool to predict the temporal and spectral properties of the output pulse for nearly Gaussian beams, in a wide range of cavity configurations and nonlinearity levels. This model allows us to drastically reduce the computation time associated with MPC design. The validity of the 1D model is first checked by comparing it to 3D simulations. The results of the 1D model are then compared with experimental data collected from a near-concentric gas-filled multipass cell presenting a high level of nonlinearity, enabling the observation of wave breaking. In a second part, we experimentally characterize the spatio-spectral profile at the output of this experimental setup, both with an imaging spectrometer and with a complete 3D characterization method known as INSIGHT. The results show that gas-filled multipass cells can be used at peak power levels close to the critical power without inducing significant spatio-spectral couplings in intensity or phase.
BibTeX:
@article{Daher2020,
  author = {Daher, Nour and Guichard, Florent and Jolly, Spencer W. and Délen, Xavier and Quéré, Fabien and Hanna, Marc and Georges, Patrick},
  title = {Multipass cells: 1D numerical model and investigation of spatio-spectral couplings at high nonlinearity},
  journal = {J. Opt. Soc. Am. B},
  publisher = {OSA},
  year = {2020},
  volume = {37},
  number = {4},
  pages = {993--999},
  url = {http://josab.osa.org/abstract.cfm?URI=josab-37-4-993},
  doi = {10.1364/JOSAB.386049}
}
  
"Massively parallel algorithms for realistic PIC simulations of ultra high intensity laser-plasma interaction, application to attosecond pulses separation of Doppler harmonics"
Kallala H, Thesis at: Université Paris-Saclay., February, 2020. (2020UPASS052), (2020).
Abstract: The complexity of the physical mechanisms involved in ultra-high intensity laser-plasma interaction requires the use of particularly heavy PIC simulations. At the heart of these computational codes, high-order pseudo-spectral Maxwell solvers have many advantages in terms of numerical accuracy. This numerical approach comes however with an expensive computational cost. Indeed, existing parallelization methods for pseudo-spectral solvers are only scalable to few tens of thousands of cores, or induce an important memory footprint, which also hinders the scaling of the method at large scales. In this thesis, we developed a novel, arbitrarily scalable, parallelization strategy for pseudo-spectral Maxwell's equations solvers which combines the advantages of existing parallelization techniques. This method proved to be more scalable than previously proposed approaches, while ensuring a significant drop in the total memory use.By capitalizing on this computational work, we conducted an extensive numerical and theoretical study in the field of high order harmonics generation on solid targets. In this context, when an ultra-intense (I>10¹⁶W.cm⁻²) ultra-short (few tens of femtoseconds) laser pulse irradiates a solid target, a reflective overdense plasma mirror is formed at the target-vacuum interface. The subsequent laser pulse non linear reflection is accompanied with the emission of coherent high order laser harmonics, in the form of attosecond X-UV light pulses (1 attosecond = 10⁻¹⁸s). For relativistic laser intensities (I>10¹⁹ W.cm⁻²), the plasma surface is curved under the laser radiation pressure. And the plasma mirror acts as a focusing optics for the radiated harmonic beam. In this thesis, we investigated feasible ways for producing isolated attosecond light pulses from relativistic plasma-mirror harmonics, with the so called attosecond lighthouse effect. This effect relies introducing a wavefront rotation on the driving laser pulse in order to send attosecond pulses emitted during different laser optical cycles along different directions. In the case of high order harmonics generated in the relativistic regime, the plasma mirror curvature significantly increases the attosecond pulses divergence and prevents their separation with the attosecond lighthouse scheme. For this matter, we developed two harmonic divergence reduction techniques, based on tailoring the laser pulse phase or amplitude profiles in order to significantly inhibit the plasma mirror focusing effect and allow for a clear separation of attosecond light pulses by reducing the harmonic beam divergence. Furthermore, we developed an analytical model to predict optimal interaction conditions favoring attosecond pulses separation. This model was fully validated with 2D and 3D PIC simulations over a broad range of laser and plasma parameters. In the end, we show that under realistic laser and plasma conditions, it is possible to produce isolated attosecond pulses from Doppler harmonics.
BibTeX:
@phdthesis{kallala:tel-02910065,
  author = {Kallala, Haithem},
  title = {Massively parallel algorithms for realistic PIC simulations of ultra high intensity laser-plasma interaction, application to attosecond pulses separation of Doppler harmonics},
  school = {Université Paris-Saclay},
  year = {2020},
  number = {2020UPASS052},
  url = {https://theses.hal.science/tel-02910065}
}
"Étude théorique et numérique de la génération d'harmoniques XUV à l'aide de lasers ultra-intenses sur feuilles minces"
Bouchard G., Thesis at: Université Paris-Saclay., February, 2020. (2020UPASS037), (2020).
Abstract: Lors de la focalisation d’un laser femto seconde ultra-intense (Iλ0² > 10¹⁶ W.cm⁻ ²) sur un solide, le champ laser incident est suffisamment intense pour ioniser presque totalement la cible dès le début de l’impulsion. Ainsi la plus grande partie du laser est réfléchis dans la direction spéculaire par le plasma dense créé jusqu’alors : C’est un miroir plasma. Le champ laser ultra-intense accélère les électrons à la surface alors qu’ils sont extraits du plasma à des vitesses proche de c. À chaque période laser, les électrons sont ainsi la source d’un rayonnement de très haute fréquence, pouvant s’étendre jusqu’à l’extrême ultraviolet voir jusqu’au domaine X. Cette périodicité dans la génération se traduit par l’apparition d’un spectre d’harmoniques de la fréquence laser ω₀. Les électrons sont finalement renvoyés dans le plasma avec des vitesses très proche de la vitesse de la lumière. Bien que les mécanismes de génération dans le domaine XUV soient bien identifiés en réflexion aujourd’hui peu d’études ont été menées pour comprendre d’où pouvait provenir le rayonnement émis dans la direction de transmission. L’objectif de cette thèse est de mieux comprendre l’interaction laser-plasma dans le cas où l’épaisseur de la cible est de l’ordre de la longueur d’onde. En particulier, on étudiera dans l’émission le rôle des jets d’électrons relativistes, renvoyés dans le plasma, lorsque ces derniers traversent la face arrière de la cible. La première partie de ce manuscrit s’intéresse aux mécanismes déjà identifiés pour expliquer la génération d’impulsions XUV dans la direction spéculaire. On se demande alors dans quelles mesures ces modèles sont insuffisants pour décrire le rayonnement émis dans la direction de transmission. La seconde partie de ce manuscrit s’intéresse aux méthodes FDTD (Finite Difference Time Domain) utilisées dans les codes "Particle-in-Cell", en particulier à deux effets numériques induits par cette méthode et potentiellement néfastes pour les simulations : La dispersion numérique et l’instabilité Cherenkov numérique. On essayera ici d’apporter une amélioration aux algorithmes classiques diminuant l’impact de la dispersion et de l’instabilité Cherenkov sur les résultats. Enfin on identifiera un tout nouveau mécanisme de rayonnement XUV cohérent : Le rayonnement cohérent par freinage plasma. Lorsque les électrons quittent le plasma, un champ de charge espace de plusieurs TV apparait sur la surface arrière. Ce champ de freinage longitudinal accélère transversalement les jets d’électrons relativistes créés par les cycles optiques suivants. Ces jets émettent alors des impulsions lumineuses d’une centaine d’attoseconde.
BibTeX:
@phdthesis{bouchard:tel-02967252,
  author = {Bouchard, Guillaume},
  title = {Étude théorique et numérique de la génération d'harmoniques XUV à l'aide de lasers ultra-intenses sur feuilles minces},
  school = {Université Paris-Saclay},
  year = {2020},
  number = {2020UPASS037},
  url = {https://theses.hal.science/tel-02967252}
}
"Spatio-temporal characterization of femtosecond laser pulses using self-referenced Fourier transform spectroscopy"
Jeandet A, Thesis at: Université Paris-Saclay., July, 2020. (2020UPASS089), (2020).
Abstract: Current ultrashort laser technology makes it possible to generate pulses lasting a few tens of femtoseconds, with energies of up to tens of joules. Strongly focusing such pulses produces ultra-intense fields that are notably used to generate relativistic particle beams. Proper operation of ultra-intense laser facilities requires to control the temporal and spatial properties of ultrashort pulses. Until now, measurement devices used for this purpose have neglected an important aspect of ultrashort pulses structure, which is linked to spatio-temporal couplings. Spatio-temporal couplings are a particular kind of defects in ultrashort pulses, of which the influence on ultra-intense experiments has been largely overlooked until recently. The rare instruments capable of measuring spatio-temporal couplings are hardly scalable to high-energy laser beams. This thesis is dedicated to TERMITES, a device for the full characterization of ultrashort laser beam, which is used to provide their three dimensional shape in space and time. TERMITES is a self-referenced technique based on spatially-resolved Fourier-Transform Spectroscopy. The first part of this work presents the detailed study of TERMITES, as well as the optimization of its design. Multiple laser systems are then characterized using the instrument. The obtained results are used to establish the first experimental review of spatio-temporal couplings origins in ultrashort lasers.
BibTeX:
@phdthesis{jeandet:tel-03018886,
  author = {Jeandet, Antoine},
  title = {Spatio-temporal characterization of femtosecond laser pulses using self-referenced Fourier transform spectroscopy},
  school = {Université Paris-Saclay},
  year = {2020},
  number = {2020UPASS089},
  url = {https://theses.hal.science/tel-03018886}
}
2019
"Proton acceleration by collisionless shocks using a supersonic H2 gas-jet target and high-power infrared laser pulses"
Puyuelo-Valdes P, Henares JL, Hannachi F, Ceccotti T, Domange J, Ehret M, d'Humieres E, Lancia L, Marquès J-R, Ribeyre X, Santos JJ, Tikhonchuk V & Tarisien M, Physics of Plasmas., December, 2019. Vol. 26(12), pp. 123109. American Institute of Physics,(2019).
Abstract: For most laser-driven ion acceleration applications, a well-characterized intense ion beam with a low divergence and a controllable energy spectrum produced at a high repetition rate is needed. Gas-jet targets have given promising results in simulations, and they have several technical advantages for high-repetition-rate lasers. In this work, we report on proton acceleration to energies up to 6 MeV using a supersonic H2 gas-jet target at the LULI PICO2000 laser facility. The experimental results are compared with the plasma hydrodynamics and the particle-in-cell simulations to identify the acceleration mechanisms at play
BibTeX:
@article{Puyuelo-Valdes2019,
  author = {Puyuelo-Valdes, P. and Henares, J. L. and Hannachi, F. and Ceccotti, T. and Domange, J. and Ehret, M. and d'Humieres, E. and Lancia, L. and Marquès, J.-R. and Ribeyre, X. and Santos, J. J. and Tikhonchuk, V. and Tarisien, M.},
  title = {Proton acceleration by collisionless shocks using a supersonic H2 gas-jet target and high-power infrared laser pulses},
  journal = {Physics of Plasmas},
  publisher = {American Institute of Physics},
  year = {2019},
  volume = {26},
  number = {12},
  pages = {123109},
  url = {https://doi.org/10.1063/1.5116337},
  doi = {10.1063/1.5116337}
}
"Achieving Extreme Light Intensities using Optically Curved Relativistic Plasma Mirrors"
Vincenti H, Physical Review Letters., Sep, 2019. Vol. 123, pp. 105001. American Physical Society. (2019).
Abstract: This Letter proposes a realistic implementation of the curved relativistic mirror concept to reach unprecedented light intensities in experiments. The scheme is based on relativistic plasma mirrors that are optically curved by laser radiation pressure. Its validity is supported by cutting-edge three-dimensional particle-in-cell simulations and a theoretical model, which show that intensities above 1025 W cm-2 could be reached with a 3 PetaWatt (PW) laser. Its very high robustness to laser and plasma imperfections is shown to surpass all previous schemes and should enable its implementation on existing PW laser facilities.
BibTeX:
@article{PhysRevLett.123.105001,
  author = {Vincenti, Henri},
  title = {Achieving Extreme Light Intensities using Optically Curved Relativistic Plasma Mirrors},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2019},
  volume = {123},
  pages = {105001},
  url = {https://link.aps.org/doi/10.1103/PhysRevLett.123.105001},
  doi = {10.1103/PhysRevLett.123.105001}
}
"Physique attoseconde relativiste sur miroirs plasmas"
Chopineau L, Thesis at: Université Paris Saclay (COmUE)., September, 2019. (2019SACLS132), (2019).
Abstract: Lors de la réflexion d’un laser femtoseconde ultra-intense [IL 1016 W/cm²] sur une cible solide, celle-ci est ionisée dès les premiers cycles de l’impulsion. Un plasma se détend alors vers le vide avec un profil exponentiel de longueur caractéristique Lg. Pour de faibles longueurs de gradient Lg < λLsub>, le gradient plasma est considéré comme raide, il réfléchit spéculairement l’impulsion incidente : c’est un miroir plasma. De tels plasmas, réfléchissant pour la lumière, sont aujourd’hui exploités dans différentes applications scientifiques, comme l’accélération de particules par laser ou encore la génération d’harmoniques d’ordre élevé, associées dans le domaine temporel à un train d’impulsions attosecondes. Néanmoins, pour favoriser ces émissions de lumière ou de particules, le transfert d’énergie entre l’impulsion laser incidente et le plasma est essentiel. L’objectif de cette thèse est de mieux comprendre ces interactions à l’aide de la caractérisation de ces deux observables physiques qui en sont issues : les émissions d’électrons relativistes et d’harmoniques d’ordre élevé. Tout d’abord, nous reportons dans ce manuscrit la première étude expérimentale et numérique détaillée des mécanismes de couplage laser-plasma dense impliqués en régime relativiste [IL 10¹⁸ W/cm²] en fonction notamment de la longueur caractéristique de gradient Lg. Cette étude a notamment permis d’identifier deux régimes distincts en fonction des conditions d’interaction, éclaircissant ainsi la physique régissant ces systèmes. Par ailleurs, au delà de cet aspect fondamental, le contrôle de ces sources est également essentiel pour de futures expériences. Pour cela, différentes approches permettant de mettre en forme spatialement et temporellement ces impulsions de lumière ultra-brèves ont été étudiées au cours de ce doctorat, ouvrant ainsi de nouvelles perspectives pour l’utilisation de ces sources. En particulier, nous démontrons qu’il est possible d’introduire un moment angulaire orbital aux impulsions XUV attosecondes via la mise en forme spatiale du faisceau IR femtoseconde incident ou bien de plasma dense créé à la surface de la cible mais également de contrôler la dynamique des électrons de surface du plasma à l’échelle attoseconde à l’aide d’un champ incident à deux couleurs. Finalement, une méthode novatrice basée sur des mesures de ptychographie dynamique a été développée afin de caractériser spatio-temporellement ces impulsions de lumière ultra-brèves, constituant un enjeu majeur pour la communauté.
BibTeX:
@phdthesis{chopineau:tel-02413406,
  author = {Chopineau, Ludovic},
  title = {Physique attoseconde relativiste sur miroirs plasmas},
  school = {Université Paris Saclay (COmUE)},
  year = {2019},
  number = {2019SACLS132},
  url = {https://theses.hal.science/tel-02413406}
}
"A generalized massively parallel ultra-high order FFT-based Maxwell solver"
Kallala H, Vay J-L et Vincenti H, Computer Physics Communications., July, (2019).
Abstract: Dispersion-free ultra-high order FFT-based Maxwell solvers have recently proven to be paramount to a large range of applications, including the high-fidelity modeling of high-intensity laser-matter interactions with Particle-In-Cell (PIC) codes. To enable a massively parallel scaling of these solvers, a novel parallelization technique was recently proposed, which consists in splitting the simulation domain into several processor sub-domains, with guard regions appended at each sub-domain boundary. Maxwell's equations are advanced independently on each sub-domain using local shared-memory FFTs (instead of a single distributed global FFT). This implies small truncation errors at sub-domain boundaries, the amplitude of which depends on guard regions sizes and order of the Maxwell solver. For moderate guard region sizes, this 'local' technique proved to be highly scalable on up to a million cores and notably enabled the 3D modelingof so-called plasma mirrors, for which 8 guard cells only were enough to prevent truncation error growth. Yet, for other applications, the required number of guard cells might be much higher, which would severely limit the parallel efficiency of this technique due to the large volume of guard cells to be exchanged between sub-domains. In this context, we propose a novel parallelization technique that ensures very good scaling of FFT-based solvers with an arbitrarily high number of guard cells. Our 'hybrid' technique consists in performing distributed FFTs on local groups of processors with guard regions now appended to boundaries of each group of processors. It uses a dual domain decomposition method for the Maxwell solver and other parts of the PIC cycle to keep the simulation load-balanced. This 'hybrid' technique was implemented in the open source exascale library PICSAR. Benchmarks show that for a large number of guard cells (>16), the 'hybrid' technique offers up to *3 speed-up and *8 memory savings compared to the 'local' one.
BibTeX:
@article{Kallala2019,
  author = {Kallala, Haithem and Vay, Jean-Luc and Vincenti, Henri},
  title = {A generalized massively parallel ultra-high order FFT-based Maxwell solver},
  journal = {Computer Physics Communications},
  year = {2019},
  url = {http://www.sciencedirect.com/science/article/pii/S0010465519302206},
  doi = {10.1016/j.cpc.2019.07.009}
}
"Extreme high field plasmonics: Electron acceleration and XUV harmonic generation from ultrashort surface plasmons"
Macchi A, Cantono G, Fedeli L, Pisani F & Ceccotti T, Physics of Plasmas., April, 2019. Vol. 26(4), pp. 042114. American Institute of Physics, (2019).
Abstract: Experiments on the excitation of propagating surface plasmons (SPs) by an ultrashort, high intensity laser interaction with grating targets are reviewed. At intensities exceeding 101019 W cm−2 on target, i.e., in the strongly relativistic regime of electron dynamics, multi-megaelectronvolt electrons are accelerated by the SP field as dense bunches collimated in a near-tangent direction. By the use of a suitable blazed grating, the bunch charge can be increased up to ≈660 pC. Intense extreme ultraviolet high harmonics (HHs) diffracted by the grating are observed when a plasma with a submicrometer scale is produced at the target surface by a controlled prepulse. When the SP is excited, the HHs are strongly enhanced in a direction quasi-parallel to the electrons. Simulations suggest that the HHs are boosted by nanobunching in the SP field of the electrons which scatter the laser field. Besides the static and dynamic tailoring of the target density profile, further control of electron and HH emission might be achieved by changing the SP duration using a laser pulse with a rotating wavefront. The latter technique may allow the production of nearly single-cycle SPs.
BibTeX:
@article{Macchi2019,
  author = {Macchi, A. and Cantono, G. and Fedeli, L. and Pisani, F. and Ceccotti, T.},
  title = {Extreme high field plasmonics: Electron acceleration and XUV harmonic generation from ultrashort surface plasmons},
  journal = {Physics of Plasmas},
  publisher = {American Institute of Physics},
  year = {2019},
  volume = {26},
  number = {4},
  pages = {042114},
  url = {https://doi.org/10.1063/1.5086537},
  doi = {10.1063/1.5086537}
}
"Influence of longitudinal chromatism on vacuum acceleration by intense radially polarized laser beams"
Jolly SW, Optics Letters, April, 2019. Vol. 44(7), pp. 1833-1836. OSA, (2019).
Abstract: We report with single-particle simulations that longitudinal chromatism, a commonly occurring spatio-temporal coupling in ultrashort laser pulses, can have a significant influence in the longitudinal acceleration of electrons via high-power, tightly-focused, and radially polarized laser beams. This effect can be advantageous, and even more so when combined with small values of temporal chirp. However, the effect can also be highly destructive when the magnitude and sign of the longitudinal chromatism is not ideal, even at very small magnitudes. This motivates the characterization and understanding of the driving laser pulses and further study of the influence of similar low-order spatial-temporal couplings on such acceleration.
BibTeX:
@article{Jolly2019,
  author = {Jolly, Spencer W.},
  title = {Influence of longitudinal chromatism on vacuum acceleration by intense radially polarized laser beams},
  journal = {Opt. Lett.},
  publisher = {OSA},
  year = {2019},
  volume = {44},
  number = {7},
  pages = {1833--1836},
  url = {http://ol.osa.org/abstract.cfm?URI=ol-44-7-1833}
}
"Identification of Coupling Mechanisms between Ultraintense Laser Light and Dense Plasmas"
Chopineau L, Leblanc A, Blaclard G, Denoeud A, Thévenet M, Vay J-L, Bonnaud G, Martin P, Vincenti H et Quéré F, Physical Review X., Mar, 2019. Vol. 9, pp. 011050. American Physical Society, (2019).
Abstract: The interaction of intense laser beams with plasmas created on solid targets involves a rich nonlinear physics. Because such dense plasmas are reflective for laser light, the coupling with the incident beam occurs within a thin layer at the interface between plasma and vacuum. One of the main paradigms used to understand this coupling, known as the Brunel mechanism, is expected to be valid only for very steep plasma surfaces. Despite innumerable studies, its validity range remains uncertain, and the physics involved for smoother plasma-vacuum interfaces is unclear, especially for ultrahigh laser intensities. We report the first comprehensive experimental and numerical study of the laser-plasma coupling mechanisms as a function of the plasma interface steepness, in the relativistic interaction regime. Our results reveal a clear transition from the temporally periodic Brunel mechanism to a chaotic dynamic associated to stochastic heating. By revealing the key signatures of these two distinct regimes on experimental observables, we provide an important landmark for the interpretation of future experiments.
BibTeX:
@article{PhysRevX.9.011050,
  author = {Chopineau, L. and Leblanc, A. and Blaclard, G. and Denoeud, A. and Thévenet, M. and Vay, J-L. and Bonnaud, G. and Martin, Ph. and Vincenti, H. and Quéré, F.},
  title = {Identification of Coupling Mechanisms between Ultraintense Laser Light and Dense Plasmas},
  journal = {Phys. Rev. X},
  publisher = {American Physical Society},
  year = {2019},
  volume = {9},
  pages = {011050},
  url = {https://link.aps.org/doi/10.1103/PhysRevX.9.011050},
  doi = {10.1103/PhysRevX.9.011050}
}
"High-order harmonic generation in an active grating"
Chappuis C, Bresteau D, Auguste T, Gobert O et Ruchon T , Physical Review A., Mar, 2019. Vol. 99, pp. 033806. American Physical Society, (2019).
Abstract: We study theoretically and experimentally high-order harmonic generation (HHG) using two noncollinear driving fields focused in gases. We show that these two fields form a nonstationary blazed active grating in the generation medium. The intensity and phase structure of this grating rule the far-field properties of the emission, such as the relative amplitude of the diffraction orders. Full macroscopic calculations and experiments support this wave-based picture of the process, complementing and extending its standard "photon" picture. This insight into the HHG process allows us to envision structuration schemes to convert femtosecond lasers to attosecond pulses with increased efficiency.
BibTeX:
@article{PhysRevA.99.033806,
  author = {Chappuis, C. and Bresteau, D. and Auguste, T. and Gobert, O. and Ruchon, T.},
  title = {High-order harmonic generation in an active grating},
  journal = {Phys. Rev. A},
  publisher = {American Physical Society},
  year = {2019},
  volume = {99},
  pages = {033806},
  url = {https://link.aps.org/doi/10.1103/PhysRevA.99.033806},
  doi = {10.1103/PhysRevA.99.033806}
}
2018
"Optical Control of the Topology of Laser-Plasma Accelerators"
Vieira J, Mendonça JT et Quéré F, Physical Review Letters., Jul, 2018. Vol. 121, pp. 054801. American Physical Society, (2018).
Abstract: We propose a twisted plasma accelerator capable of generating relativistic electron vortex beams with helical current profiles. The angular momentum of these vortex bunches is quantized, dominates their transverse motion, and results in spiraling particle trajectories around the twisted wakefield. We focus on a laser wakefield acceleration scenario, driven by a laser beam with a helical spatiotemporal intensity profile, also known as a light spring. We find that these light springs can rotate as they excite the twisted plasma wakefield, providing a new mechanism to control the twisted wakefield phase velocity and enhance energy gain and trapping efficiency beyond planar wakefields.
BibTeX:
@article{PhysRevLett.121.054801,
  author = {Vieira, J. and Mendonça, J. T. and Quéré, F.},
  title = {Optical Control of the Topology of Laser-Plasma Accelerators},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2018},
  volume = {121},
  pages = {054801},
  url = {https://link.aps.org/doi/10.1103/PhysRevLett.121.054801},
  doi = {10.1103/PhysRevLett.121.054801}
}
"Spatio-spectral metrology at focus of ultrashort lasers: a phase-retrieval approach"
Borot A et Quéré F, Opt. Express., October, 2018. Vol. 26(20), pp. 26444-26461. OSA, (2018).
Abstract: The complete characterization of an ultrashort laser beam ultimately requires the determination of its spatio-temporal electric field E(xyt), or its spatio-spectral counterpart (xy, ω). We describe a new measurement technique called INSIGHT, which determines (xyω), up to an unknown spatially-homogeneous spectral phase. Combining this information with a temporal measurement at a single point of the beam then enables the determination of the spatio-temporal field E(xyt). This technique is based on the combination of spatially-resolved Fourier-transform spectroscopy with an alternate-projection phase-retrieval algorithm. It can be applied to any reproducible laser source with a repetition rate higher than about 0.1 Hz, relies on a very simple device, does not require any reference beam, and circumvents the difficulty associated with the manipulation of large beam diameters by working in the vicinity of the beam focus. We demonstrate INSIGHT on a 100 TW-25 fs laser, and use the measurement results to introduce new representations for the analysis of spatio-temporal/spectral couplings of ultrashort lasers.
BibTeX:
@article{Borot2018,
  author = {Borot, Antonin and Quéré, Fabien},
  title = {Spatio-spectral metrology at focus of ultrashort lasers: a phase-retrieval approach},
  journal = {Opt. Express},
  publisher = {OSA},
  year = {2018},
  volume = {26},
  number = {20},
  pages = {26444--26461},
  url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-26-20-26444},
  doi = {10.1364/OE.26.026444}
}
"Two-step perfectly matched layer for arbitrary-order pseudo-spectral analytical time-domain methods"
Shapoval O, Vay J-L et Vincenti H, Computer Physics Communications., February, 2019. Vol. 235, pp. 102-110, (2018).
Abstract: Numerical simulation of an electrodynamic system in empty space requires the implementation of open boundary conditions (BC) to terminate the solution of Maxwell's equations on the boundaries of the computational domain. The Perfectly Matched Layer (PML) has become the method of choice for open BC with wave equations, as it is straightforward and relatively easy to implement, and offers very efficient and user-adjustable absorption rates. PMLs are most often employed with the Finite-Difference Time-Domain (FDTD) algorithm, which in its most common implementation offers second-order accuracy in space and time on Cartesian grids. Yet, simulations (including some class of electromagnetic Particle-In-Cell simulations) that require higher precision may resort to higher-order Maxwell solvers employing extended finite-difference stencils, or even to pseudo-spectral Maxwell solvers, for which a general, versatile and efficient formulation of the PML has been missing so far. In this paper, we propose a novel "two-step" formulation of the PML that is simple, very versatile and can be used as is with any Maxwell solver. In particular, it is applicable to a large class of Maxwell solvers including the arbitrary-order Pseudo-Spectral Analytical Time-Domain (PSATD) solver, which offers arbitrarily low numerical dispersion when increasing solver order and becomes dispersion-free at infinite order. Analysis and numerical simulations demonstrate that the new formulation is as efficient as the standard PML formulation, both for the FDTD and the PSATD implementations.
BibTeX:
@article{Shapoval2019,
  author = {Shapoval, Olga and Vay, Jean-Luc and Vincenti, Henri},
  title = {Two-step perfectly matched layer for arbitrary-order pseudo-spectral analytical time-domain methods},
  journal = {Computer Physics Communications},
  year = {2019},
  volume = {235},
  pages = {102--110},
  url = {http://www.sciencedirect.com/science/article/pii/S0010465518303291},
  doi = {10.1016/j.cpc.2018.09.015}
}
"Transport and analysis of electron beams from a laser wakefield accelerator in the 100 MeV energy range with a dedicated magnetic line"
Maitrallain A, Audet TL, Dobosz Dufrénoy S, Chancé A, Maynard G, Lee P, Mosnier A, Schwindling J, Delferrière O, Delerue N, Specka A, Monot P et Cros B, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment., November, 2018. Vol. 908, pp. 159-166, (2018).
Abstract: Electron bunches generated by laser driven wakefield acceleration are transported and analyzed using a magnetic line composed of a triplet of quadrupoles and a dipole. Short pulse bunches with a total charge of ≈130pC, and broad band energy spectra in the range 45 to 150MeV are generated by ionization assisted injection in a gas cell. The electron source is imaged about one meter away from the exit of the gas cell by the magnetic line, delivering electron bunches at a stable position in the image plane where a charge density of ≈2.9pC/mm2 at an energy of 69.4±0.6MeV is achieved. This magnetic line improves dramatically the accuracy of energy determination of this electron source, leading to an energy error as low as 8.6‰ in the 70MeV range for 5mrad divergence electron bunch and considering the resolution of the entire detection system. The transport of bunches with improved stability and energy selection paves the way to various applications including multi-stage laser plasma acceleration.
BibTeX:
@article{Maitrallain2018,
  author = {Maitrallain, A. and Audet, T. L. and Dobosz Dufrénoy, S. and Chancé, A. and Maynard, G. and Lee, P. and Mosnier, A. and Schwindling, J. and Delferrière, O. and Delerue, N. and Specka, A. and Monot, P. and Cros, B.},
  title = {Transport and analysis of electron beams from a laser wakefield accelerator in the 100 MeV energy range with a dedicated magnetic line},
  journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  year = {2018},
  volume = {908},
  pages = {159--166},
  url = {http://www.sciencedirect.com/science/article/pii/S0168900218309501},
  doi = {10.1016/j.nima.2018.08.004}
}
"Extreme Ultraviolet Beam Enhancement by Relativistic Surface Plasmons"
Cantono G, Fedeli L, Sgattoni A, Denoeud A, Chopineau L, Réau F, Ceccotti T et Macchi A (2018), Phys. Rev. Lett., Jun, 2018. Vol. 120, pp. 264803. American Physical Society, (2018).
Abstract: The emission of high-order harmonics in the extreme ultraviolet range from the interaction of a short, intense laser pulse with a grating target is investigated experimentally. When resonantly exciting a surface plasmon, both the intensity and the highest order observed for the harmonic emission along the grating surface increase with respect to a flat target. Harmonics are obtained when a suitable density gradient is preformed at the target surface, demonstrating the possibility to manipulate the grating profile on a nanometric scale without preventing the surface plasmon excitation. In support of this, the harmonic emission is spatiotemporally correlated to the acceleration of multi-MeV electron bunches along the grating surface. Particle-in-cell simulations reproduce the experimental results and give insight on the mechanism of high harmonic generation in the presence of surface plasmons.
BibTeX:
@article{PhysRevLett.120.264803,
  author = {Cantono, G. and Fedeli, L. and Sgattoni, A. and Denoeud, A. and Chopineau, L. and Réau, F. and Ceccotti, T. and Macchi, A.},
  title = {Extreme Ultraviolet Beam Enhancement by Relativistic Surface Plasmons},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2018},
  volume = {120},
  pages = {264803},
  url = {https://link.aps.org/doi/10.1103/PhysRevLett.120.264803},
  doi = {10.1103/PhysRevLett.120.264803}
}
"Ultrahigh-order Maxwell solver with extreme scalability for electromagnetic PIC simulations of plasmas"
Vincenti H et Vay J-L, Computer Physics Communications., Vol. 228, pp. 22-29, (2018).
Abstract: The advent of massively parallel supercomputers, with their distributed-memory technology using many processing units, has favored the development of highly-scalable local low-order solvers at the expense of harder-to-scale global very high-order spectral methods. Indeed, FFT-based methods, which were very popular on shared memory computers, have been largely replaced by finite-difference (FD) methods for the solution of many problems, including plasmas simulations with electromagnetic Particle-In-Cell methods. For some problems, such as the modeling of so-called "plasma mirrors" for the generation of high-energy particles and ultra-short radiations, we have shown that the inaccuracies of standard FD-based PIC methods prevent the modeling on present supercomputers at sufficient accuracy. We demonstrate here that a new method, based on the use of local FFTs, enables ultrahigh-order accuracy with unprecedented scalability, and thus for the first time the accurate modeling of plasma mirrors in 3D.
BibTeX:
@article{Vincenti2018,
  author = {Vincenti, Henri and Vay, Jean-Luc},
  title = {Ultrahigh-order Maxwell solver with extreme scalability for electromagnetic PIC simulations of plasmas},
  journal = {Computer Physics Communications},
  year = {2018},
  volume = {228},
  pages = {22--29},
  url = {http://www.sciencedirect.com/science/article/pii/S0010465518300900},
  doi = {10.1016/j.cpc.2018.03.018}
}
"Surface plasma attosource beamlines at ELI-ALPS"
Mondal S, Shirozhan M, Ahmed N, Bocoum M, Boehle F, Vernier A, Haessler S, Lopez-Martens R, Sylla F, Sire C, Quéré F, Nelissen K, Varjú K, Charalambidis D et Kahaly S (2018), Journal of the Optical Society of America B, Vol. 35(5), pp. A93-A102. OSA, 2018.
Abstract: ELI-ALPS, one of the three pillars of the Extreme Light Infrastructure (ELI) project, will be in a unique position to offer dedicated experimental platforms for ultrashort time-resolved investigations of strongly excited dynamical systems. The state-of-the-art surface plasma attosource (SPA) beamlines at ELI-ALPS are being designed and developed to enable new directions in plasma-based attoscience research. The SPA beamlines will be driven by ultrashort, high peak power, high repetition rate lasers based on the latest technology and are aimed to develop previously unavailable attoscience experimental platforms employing surface high-harmonic generation process. This endeavor involves research and development challenges and careful considerations. Here we discuss the physics of plasma attosources and their characteristics under such extreme conditions and the beamline functionalities that would facilitate these objectives. Finally, we delineate the initial research possibilities with these sophisticated instruments.
BibTeX:
@article{Mondal2018,
  author = {Mondal, Sudipta and Shirozhan, Mojtaba and Ahmed, Naveed and Bocoum, Maïmouna and Boehle, Frederik and Vernier, Aline and Haessler, Stefan and Lopez-Martens, Rodrigo and Sylla, François and Sire, Cedric and Quéré, Fabien and Nelissen, Kwinten and Varjú, Katalin and Charalambidis, Dimitris and Kahaly, Subhendu},
  title = {Surface plasma attosource beamlines at ELI-ALPS},
  journal = {J. Opt. Soc. Am. B},
  publisher = {OSA},
  year = {2018},
  volume = {35},
  number = {5},
  pages = {A93--A102},
  url = {http://josab.osa.org/abstract.cfm?URI=josab-35-5-A93},
  doi = {10.1364/JOSAB.35.000A93}
}
"Effects of the dopant concentration in laser wakefield and direct laser acceleration of electrons"
González IG, Ekerfelt H, Hansson M, Audet TL, Aurand B, Desforges FG, Dobosz Dufrénoy S, Persson A, Davoine X, Wahlström C-G, Cros B et Lundh O, New Journal of Physics. Vol. 20(5), pp. 053011, (2018).
Abstract: In this work, we experimentally study the effects of the nitrogen concentration in laser wakefield acceleration of electrons in a gas mixture of hydrogen and nitrogen. A 15 TW peak power laser pulse is focused to ionize the gas, excite a plasma wave and accelerate electrons up to 230 MeV. We find that at dopant concentrations above 2% the total divergence of the electrons is increased and the high energy electrons are emitted preferentially with an angle of ±6 mrad, leading to a forked spatio-spectral distribution associated to direct laser acceleration (DLA). However, electrons can gain more energy and have a divergence lower than 4 mrad for concentrations below 0.5% and the same laser and plasma conditions. Particle-in-cell simulations show that for dopant concentrations above 2%, the amount of trapped charge is large enough to significantly perturb the plasma wave, reducing the amplitude of the longitudinal wakefield and suppressing other trapping mechanisms. At high concentrations the number of trapped electrons overlapping with the laser fields is increased, which rises the amount of charge affected by DLA. We conclude that the dopant concentration affects the quantity of electrons that experience significant DLA and the beam loading of the plasma wave driven by the laser pulse. These two mechanisms influence the electrons final energy, and thus the dopant concentration should be considered as a factor for the optimization of the electron beam parameters.
BibTeX:
@article{Gonzalez2018,
  author = {González, I. Gallardo and Ekerfelt, H. and Hansson, M. and Audet, T. L. and Aurand, B. and Desforges, F. G. and Dobosz Dufrénoy, S. Dobosz and Persson, A. and Davoine, X. and Wahlström, C.-G. and Cros, B. and Lundh, O.},
  title = {Effects of the dopant concentration in laser wakefield and direct laser acceleration of electrons},
  journal = {New Journal of Physics},
  year = {2018},
  volume = {20},
  number = {5},
  pages = {053011},
  url = {http://stacks.iop.org/1367-2630/20/i=5/a=053011},
  doi = {10.1088/1367-2630/aabe14}
}
"Attosecond metrology of partially coherent photoelectron wavepackets"
Bourassin-Bouchet C, Barreau L, Gruson V, Quéré F, Ruchon T et Salières P (2018), High-Brightness Sources and Light-driven Interactions., In High-Brightness Sources and Light-driven Interactions. Strasbourg, March, 2018. , pp. EW3B.3. Optical Society of America.
Abstract: We developed a novel experimental technique named Mixed-FROG for the metrology of attosecond XUV pulses. This method provides information on both the coherent and incoherent phenomena that take place during the pulse characterization.
BibTeX:
@inproceedings{Bourassin-Bouchet2018,
  author = {Bourassin-Bouchet, C. and Barreau, L. and Gruson, V. and Qur, F. and Ruchon, T. and Salires, P.},
  title = {Attosecond metrology of partially coherent photoelectron wavepackets},
  booktitle = {High-Brightness Sources and Light-driven Interactions},
  journal = {High-Brightness Sources and Light-driven Interactions},
  publisher = {Optical Society of America},
  year = {2018},
  pages = {EW3B.3},
  url = {http://www.osapublishing.org/abstract.cfm?URI=EUVXRAY-2018-EW3B.3},
  doi = {10.1364/EUVXRAY.2018.EW3B.3}
}
"Extensive study of electron acceleration by relativistic surface plasmons"
Cantono G, Sgattoni A, Fedeli L, Garzella D, Réau F, Riconda C, Macchi A et Ceccotti T (2018), Physics of Plasmas., March, 2018. Vol. 25(3), pp. 031907. American Institute of Physic,(2018).
Abstract: The excitation of surface plasmons with ultra-intense(I~ 5 × 1019 W/cm2), high contrast (~1012) laser pulses on periodically modulated solid targets has been recently demonstrated to produce collimated bunches of energetic electrons along the target surface [Fedeli et al., Phys. Rev. Lett. 116, 015001 (2016)]. Here, we report an extensive experimental and numerical study aimed to a complete characterization of the acceleration mechanism, demonstrating its robustness and promising characteristics for an electron source. By comparing different grating structures, we identify the relevant parameters to optimize the acceleration and obtain bunches of ~650 pC of charge at several MeV of energy with blazed gratings.
BibTeX:
@article{Cantono2018,
  author = {Cantono, G. and Sgattoni, A. and Fedeli, L. and Garzella, D. and Rau, F. and Riconda, C. and Macchi, A. and Ceccotti, T.},
  title = {Extensive study of electron acceleration by relativistic surface plasmons},
  journal = {Physics of Plasmas},
  publisher = {American Institute of Physics},
  year = {2018},
  volume = {25},
  number = {3},
  pages = {031907},
  url = {https://doi.org/10.1063/1.5017706},
  doi = {10.1063/1.5017706}
}
"Gas cell density characterization for laser wakefield acceleration"
Audet TL, Lee P, Maynard G, Dobosz Dufrénoy S, Maitrallain A, Bougeard M, Monot P et Cros B, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment., January, (2018).
Abstract: In the design of laser plasma electron injectors for multi-stage laser driven wakefield accelerators, the control of plasma density is a key element to stabilize the acceleration process. A cell with variable parameters is used to confine the gas and tailor the density profile. The gas filling process was characterized both experimentally and by fluid simulations. Results show a good agreement between experiments and simulations. Simulations were also used to study the effect of each of the gas cell parameters on the density distribution and show the possibility to finely control the density profile.
BibTeX:
@article{Audet2018,
  author = {Audet, T. L. and Lee, P. and Maynard, G. and Dobosz Dufrénoy, S. and Maitrallain, A. and Bougeard, M. and Monot, P. and Cros, B.},
  title = {Gas cell density characterization for laser wakefield acceleration},
  journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  year = {2018},
  url = {http://www.sciencedirect.com/science/article/pii/S0168900218300706},
  doi = {10.1016/j.nima.2018.01.053}
}
2017
"Isochoric heating and strong blast wave formation driven by fast electrons in solid-density targets"
Santos JJ, Vauzour B, Touati M, Gremillet L, Feugeas J-L, Ceccotti T, Bouillaud R, Deneuville F, Floquet V, Fourment C, Hadj-Bachir M, Hulin S, Morace A, Nicolaï P, d’Oliveira P, Reau F, Samaké A, Tcherbakoff O, Tikhonchuk VT, Veltcheva M et Batani D, New Journal of Physics. Vol. 19(10), pp. 103005, (2017)
Abstract: We experimentally investigate the fast ($\lt 1\,\mathrm{ps}$) isochoric heating of multi-layer metallic foils and subsequent high-pressure hydrodynamics induced by energetic electrons driven by high-intensity, high-contrast laser pulses. The early-time temperature profile inside the target is measured from the streaked optical pyrometry of the target rear side. This is further characterized from benchmarked simulations of the laser-target interaction and the fast electron transport. Despite a modest laser energy ($\lt 1\,{\rm{J}}$), the early-time high pressures and associated gradients launch inwards a strong compression wave developing over $\gtrsim 10\,$ ps into a $\approx 140\,\mathrm{Mbar}$ blast wave, according to hydrodynamic simulations, consistent with our measurements. These experimental and numerical findings pave the way to a short-pulse-laser-based platform dedicated to high-energy-density physics studies.
BibTeX:
@article{Santos2017,
  author = {Santos, J. J. and Vauzour, B. and Touati, M. and Gremillet, L. and Feugeas, J.-L. and Ceccotti, T. and Bouillaud, R. and Deneuville, F. and Floquet, V. and Fourment, C. and Hadj-Bachir, M. and Hulin, S. and Morace, A. and Nicolaï, Ph and d’Oliveira, P. and Reau, F. and Samaké, A. and Tcherbakoff, O. and Tikhonchuk, V. T. and Veltcheva, M. and Batani, D.},
  title = {Isochoric heating and strong blast wave formation driven by fast electrons in solid-density targets},
  journal = {New Journal of Physics},
  year = {2017},
  volume = {19},
  number = {10},
  pages = {103005},
  url = {http://stacks.iop.org/1367-2630/19/i=10/a=103005}
}
"High-contrast 10 fs OPCPA-based front end for multi-PW laser chains"
Papadopoulos DN, Ramirez P, Genevrier K, Ranc L, Lebas N, Pellegrina A, Le Blanc C, Monot P, Martin L, Zou JP, Mathieu F, Audebert P, Georges P et Druon F, Opt. Lett., September, 2017. Vol. 42(18), pp. 3530-3533. OSA, (2017).
Abstract: pplications using multi-PW lasers necessitate high temporal pulse quality with a tremendous contrast ratio (CR). The first crucial prerequisite to achieve multi-PW peak power is the generation of ultrashort pulses with good spectral phase quality. Second, to avoid any deleterious pre-ionization effect on targets, nanosecond contrast better than 10 12 is also targeted. In the framework of the Apollon 10 PW French laser program, we present a high-contrast 10 fs front-end design study to inject highly energetic Ti:sapphire PW lasers. The CR has been measured and analyzed in different time ranges highlighting the different major contributions for each scale.
BibTeX:
@article{Papadopoulos2017,
  author = {Papadopoulos, D. N. and Ramirez, P. and Genevrier, K. and Ranc, L. and Lebas, N. and Pellegrina, A. and Le Blanc, C. and Monot, P. and Martin, L. and Zou, J. P. and Mathieu, F. and Audebert, P. and Georges, P. and Druon, F.},
  title = {High-contrast 10 fs OPCPA-based front end for multi-PW laser chains},
  journal = {Opt. Lett.},
  publisher = {OSA},
  year = {2017},
  volume = {42},
  number = {18},
  pages = {3530--3533},
  url = {http://ol.osa.org/abstract.cfm?URI=ol-42-18-3530},
  doi = {10.1364/OL.42.003530}
}
"Progress on the TRIPOLI-4®-Geant4 coupling"
Mancusi D, Bringer O et Monot P, EPJ Web Conf. Vol. 153, (2017).
Abstract: The capability to simulate the transport of charged and/or high-energy hadrons (especially protons) is indispensable for a number of applications. This includes, among others, simulation studies concerned with radiation protection and decommissioning around accelerators and high-intensity laser facilities, as well as beam characterisation in spallation neutron sources. In the context of Monte-Carlo particle transport codes, solving these problems often requires the use of advanced variance-reduction techniques. TRIPOLI-4® is a reference Monte-Carlo particle transport code for the simulation of low-energy (<~  20 MeV) neutrons and photons and offers a wide range of sophisticated variance-reduction schemes; however, it cannot be applied to the problems mentioned above because it lacks the capability to transport charged, high-energy hadrons.
This limitation can be circumvented by coupling TRIPOLI-4r with the Geant4 particle-transport toolkit. We present here the first results of this coupling.
BibTeX:
@article{Mancusi2017,
  author = {Mancusi, Davide and Bringer, Olivier and Monot, Pascal},
  title = {Progress on the TRIPOLI-4-Geant4 coupling},
  journal = {EPJ Web Conf.},
  year = {2017},
  volume = {153},
  url = {https://doi.org/10.1051/epjconf/201715306002},
  doi = {10.1051/epjconf/201715306002}
}
"Interaction of Ultraintense Laser Vortices with Plasma Mirrors"
Denoeud A, Chopineau L, Leblanc A et Quéré F, Phys. Rev. Lett., January, 2017. Vol. 118(3), pp. 033902-. American Physical Society, (2017).
Abstract: Laser beams carrying orbital angular momentum (OAM) have found major applications in a variety of scientific fields, and their potential for ultrahigh-intensity laser-matter interactions has since recently been considered theoretically. We present an experiment where such beams interact with plasma mirrors up to laser intensities such that the motion of electrons in the laser field is relativistic. By measuring the spatial intensity and phase profiles of the high-order harmonics generated in the reflected beam, we obtain evidence for the helical wavefronts of the high-intensity laser at focus, and study the conservation of OAM in highly nonlinear optical processes at extreme laser intensities. The physical effects determining the field mode content of the twisted harmonic beams are elucidated.
BibTeX:
@article{denoeud2017,
  author = {Denoeud, A. and Chopineau, L. and Leblanc, A. and Quéré, F.},
  title = {Interaction of Ultraintense Laser Vortices with Plasma Mirrors},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2017},
  volume = {118},
  number = {3},
  pages = {033902--},
  url = {http://link.aps.org/doi/10.1103/PhysRevLett.118.033902},
  doi = {10.1103/PhysRevLett.118.033902}
}
"Plasma holograms for ultrahigh-intensity optics"
Leblanc A, Denoeud A, Chopineau L, Mennerat G, Martin P et Quere F, Nat Phys., January, 2017. Vol. advance online publication, pp. -. Nature Publishing Group. (2017).
Abstract: The manipulation of ultraintense laser beams gets increasingly challenging with growing laser peak power, as the breakdown of conventional optics imposes ever larger beam diameters. Using compact plasma-based optical elements to control or even generate such beams is a promising approach, since plasmas can sustain considerable light intensities. We introduce a new type of plasma optics, called plasma holograms, by initiating plasma expansion on a flat solid target with a holographic prepulse beam focus. A modulated plasma surface then grows out of the target after ionization, which can be used for several picoseconds to diffract and spatially shape ultraintense laser beams. On the basis of this concept, we demonstrate the generation of fork plasma gratings, which we use to induce optical vortices on a femtosecond laser beam as well as its high-order harmonics, at intensities exceeding 1019Wcm-2. These plasma holograms open up a whole new range of possibilities for the manipulation of ultraintense lasers and the generation of structured coherent short-wavelength sources.
BibTeX:
@article{leblanc2017,
  author = {Leblanc, A. and Denoeud, A. and Chopineau, L. and Mennerat, G. and Martin, Ph. and Quere, F.},
  title = {Plasma holograms for ultrahigh-intensity optics},
  journal = {Nat Phys},
  publisher = {Nature Publishing Group},
  year = {2017},
  volume = {advance online publication},
  pages = {--},
  url = {http://dx.doi.org/10.1038/nphys4007},
  doi = {10.1038/nphys4007}
}
"Dynamic wavefront rotation in the attosecond lighthouse"
Balogh E, Zhang C, Ruchon T, Hergott J-F, Quere F, Corkum P, Nam CH et Kim KT , Optica., In Optica. Vol. 4(1), pp. 48-53. OSA, (2017).
Abstract: Attosecond pulses propagating in different directions, generated in a rotating wavefront of a driving laser field, can provide a source of multiple isolated attosecond pulses. Clear spatial separation of the attosecond pulses is attained if the divergence of the individual attosecond pulse is smaller than their angular separation, which is limited by the bandwidth of the driving laser pulse. Here we demonstrate both experimentally and numerically that an additional wavefront rotation is imposed during the propagation of the driving laser pulse in a highly ionizing medium. This dynamic wavefront rotation enables the generation of the isolated attosecond pulse even in the case when the conditions derived from a linear diffraction theory do not permit the angular separation. The described nonlinear phenomenon has its roots in the half-cycle ionization events, and may open up new ways to study strong field processes in highly ionizing media.
BibTeX:
@article{Balogh2017,
  author = {Balogh, Emeric and Zhang, Chunmei and Ruchon, Thierry and Hergott, Jean-Francois and Quere, Fabien and Corkum, Paul and Nam, Chang Hee and Kim, Kyung Taec},
  title = {Dynamic wavefront rotation in the attosecond lighthouse},
  booktitle = {Optica},
  journal = {Optica},
  publisher = {OSA},
  year = {2017},
  volume = {4},
  number = {1},
  pages = {48--53},
  url = {http://www.osapublishing.org/optica/abstract.cfm?URI=optica-4-1-48},
  doi = {10.1364/OPTICA.4.000048}
}
2016
"The Apollon 10 PW laser: experimental and theoretical investigation of the temporal characteristics"
Papadopoulos DN, Zou JP, Le Blanc C, Chériaux G, Georges P, Druon F, Mennerat G, Ramirez P, Martin L, Fréneaux A, Beluze A, Lebas N, Monot P, Mathieu F et Audebert P, High Power Laser Science and Engineering. Vol. 4, pp. e34. Cambridge University Press, (2016).
Abstract: The objective of the Apollon 10 PW project is the generation of 10 PW peak power pulses of 15 fs at 1 shot min -1 . In this paper a brief update on the current status of the Apollon project is presented, followed by a more detailed presentation of our experimental and theoretical investigations of the temporal characteristics of the laser. More specifically the design considerations as well as the technological and physical limitations to achieve the intended pulse duration and contrast are discussed.
BibTeX:
@article{Papadopoulos2016,
  author = {Papadopoulos, D. N. and Zou, J. P. and Le Blanc, C. and Chriaux, G. and Georges, P. and Druon, F. and Mennerat, G. and Ramirez, P. and Martin, L. and Frneaux, A. and Beluze, A. and Lebas, N. and Monot, P. and Mathieu, F. and Audebert, P.},
  title = {The Apollon 10PW laser: experimental and theoretical investigation of the temporal characteristics},
  journal = {High Power Laser Science and Engineering},
  publisher = {Cambridge University Press},
  year = {2016},
  volume = {4},
  pages = {e34},
  edition = {2016/09/28},
  url = {https://www.cambridge.org/core/article/apollon-10-pw-laser-experimental-and-theoretical-investigation-of-the-temporal-characteristics/CE8AD98E9CC9D424F9B43C51BB01913A},
  doi = {10.1017/hpl.2016.34}
}
"High field plasmonics and laser-plasma acceleration in solid targets"
Sgattoni A, Fedeli L, Cantono G, Ceccotti T et Macchi A, Plasma Physics and Controlled Fusion. Vol. 58(1), pp. 014004-, (2016).
Abstract: The interaction of low intensity laser pulses with metal nano-structures is at the basis of plasmonics and the excitation of surface plasmon polaritons (SP) is one of its building blocks. Some of the configurations adopted in classical plasmonics can be explored considering high intensity lasers interacting with properly structured targets. SP excitation at intensities such that the electrons quiver at relativistic velocities, poses new questions and might open new frontiers for manipulation and amplification of high power laser pulses. Here we discuss two configurations which show evidence of the resonant coupling between relativistically intense laser pulses with the SPs on plasma targets with surface modulations. Evidences of SP excitation were observed in a recent experiment when a high contrast (1012), high intensity laser pulse ($I=5\centerdot {{10}^{19}}$ W cm−2) was focussed on a grating target (engraved surface at sub-micron scale); a strong emission of multi-MeV electron bunches accelerated by SPs was observed only in conditions for the resonant SP excitation. Theoretical and numerical analysis of the Light-Sail (LS) Radiation Pressure Acceleration (RPA) regime show how the plasmonic resonant coupling of the laser light with the target rippling, affects the growth of Rayleigh Taylor Instability (RTI) driven by the radiation pressure.
BibTeX:
@article{Sgattoni2016,
  author = {Sgattoni, A and Fedeli, L and Cantono, G and Ceccotti, T and Macchi, A},
  title = {High field plasmonics and laser-plasma acceleration in solid targets},
  journal = {Plasma Physics and Controlled Fusion},
  year = {2016},
  volume = {58},
  number = {1},
  pages = {014004--},
  url = {http://stacks.iop.org/0741-3335/58/i=1/a=014004},
  doi = {10.1088/0741-3335/58/1/014004}
}
"Ion acceleration in the transparent regime and the critical influence of the plasma density scale length"
Loch RA, Ceccotti T, Quéré F, George H, Bonnaud G, Réau F, D'Oliveira P, Luttikhof MJH, Bijkerk F, Boller K-J, Blaclard G et Combis P, Physics of Plasmas., In Physics of Plasmas., September, 2016. Vol. 23(9), pp. 093117-. American Institute of Physics, (2016).
Abstract: The influence of a plasma density gradient on ions accelerated along the specular (back reflection) direction in the transparent Target Normal Sheath Acceleration regime is investigated. Enhanced acceleration of ions is experimentally observed in this regime using high-intensity and ultra-high contrast laser pulses and extremely thin foils of few nanometer thicknesses. The experimental trend for the maximum proton energy appeared quite different from the already published numerical results in this regime where an infinitely steep plasma gradient was assumed. We showed that for a realistic modelling, a finite density gradient has to be taken into account. By means of particle-in-cell (PIC) simulations, we studied for the first time the influence of the plasma density scale length on ion acceleration from these nanofoil targets. Through a qualitative agreement between our numerical particle-in-cell simulations and our experiments, the main conclusion with regard to the experimental requirements is that, in the transparent regime evidenced with nanofoils as compared to the opaque regime, the plasma expansion has to be taken into account and both the pulse contrast and the damage threshold of the material are essential parameters.
The influence of a plasma density gradient on ions accelerated along the specular (back reflection) direction in the transparent Target Normal Sheath Acceleration regime is investigated. Enhanced acceleration of ions is experimentally observed in this regime using high-intensity and ultra-high contrast laser pulses and extremely thin foils of few nanometer thicknesses. The experimental trend for the maximum proton energy appeared quite different from the already published numerical results in this regime where an infinitely steep plasma gradient was assumed. We showed that for a realistic modelling, a finite density gradient has to be taken into account. By means of particle-in-cell (PIC) simulations, we studied for the first time the influence of the plasma density scale length on ion acceleration from these nanofoil targets. Through a qualitative agreement between our numerical particle-in-cell simulations and our experiments, the main conclusion with regard to the experimental requirements is that, in the transparent regime evidenced with nanofoils as compared to the opaque regime, the plasma expansion has to be taken into account and both the pulse contrast and the damage threshold of the material are essential parameters.
BibTeX:
@article{Loch2016,
  author = {Loch, R. A. and Ceccotti, T. and Quéré, F. and George, H. and Bonnaud, G. and Réau, F. and D'Oliveira, P. and Luttikhof, M. J. H. and Bijkerk, F. and Boller, K.-J. and Blaclard, G. and Combis, P.},
  title = {Ion acceleration in the transparent regime and the critical influence of the plasma density scale length},
  booktitle = {Physics of Plasmas},
  journal = {Physics of Plasmas},
  publisher = {American Institute of Physics},
  year = {2016},
  volume = {23},
  number = {9},
  pages = {093117--},
  url = {http://dx.doi.org/10.1063/1.4962571},
  doi = {10.1063/1.4962571}
}
"Electron injector for compact staged high energy accelerator"
Audet T, Desforges F, Maitrallain A, Dobosz Dufrénoy S, Bougeard M, Maynard G, Lee P, Hansson M, Aurand B, Persson A, González IG, Monot P, Wahlström C-G, Lundh O et Cros B, ScienceDirect, in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment., In 2nd European Advanced Accelerator Concepts Workshop - EAAC 2015., September, 2016. Vol. 829, pp. 304-308 , (2016).
Abstract: An electron injector for multi-stage laser wakefield experiments is presented. It consists of a variable length gas cell of small longitudinal dimension (View the MathML source <= 10mm). The gas filling process in this cell was characterized both experimentally and with fluid simulation. Electron acceleration experiments were performed at two different laser facilities. Results show low divergence and low pointing fluctuation electron bunches suitable for transport to a second stage, and a peaked energy distribution suitable for injection into the second stage wakefield accelerator.
BibTeX:
@article{,
  author = {Audet, T.L. and Desforges, F.G. and Maitrallain, A. and Dufrénoy, S Dobosznoy, S. and Bougeard, M. and Maynard, G. and Lee, P. and Hansson, M. and Aurand, B. and Persson, A. and González, I. Gallardo and Monot, P. and Wahlström, C-G and Lundh, O. and Cros, B.},
  title = {Electron injector for compact staged high energy accelerator},
  booktitle = {2nd European Advanced Accelerator Concepts Workshop - EAAC 2015},
  journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  year = {2016},
  volume = {829},
  pages = {304--308},
  url = {http://www.sciencedirect.com/science/article/pii/S0168900216000516},
  doi = {10.1016/j.nima.2016.01.035}
}
"Space-time characterization of ultra-intense femtosecond laser beams"
Pariente G, Gallet V, Borot A, Gobert O et Quéré F, Nat Photon., August, 2016. Vol. 10(8), pp. 547-553. Nature Publishing Group, (2016).
Abstract: Femtosecond lasers can now deliver ultrahigh intensities at focus, making it possible to induce relativistic motion of charged particles with light and opening the way to new generations of compact particle accelerators and X-ray sources. With diameters of up to tens of centimetres, ultra-intense laser beams tend to suffer from spatiotemporal distortions, that is, a spatial dependence of their temporal properties that can dramatically reduce their peak intensities. At present, however, these intense electromagnetic fields are characterized and optimized in space and time separately. Here, we present the first complete spatiotemporal experimental reconstruction of the field E(t,r) for a 100 TW peak-power laser, and reveal the spatiotemporal distortions that can affect such beams. This new measurement capability opens the way to in-depth characterization and optimization of ultra-intense lasers and ultimately to the advanced control of relativistic motion of matter with femtosecond laser beams structured in space-time.
BibTeX:
@article{Pariente2016,
  author = {Pariente, G. and Gallet, V. and Borot, A. and Gobert, O. and Quéré, F.},
  title = {Space-time characterization of ultra-intense femtosecond laser beams},
  journal = {Nat Photon},
  publisher = {Nature Publishing Group},
  year = {2016},
  volume = {10},
  number = {8},
  pages = {547--553},
  url = {http://dx.doi.org/10.1038/nphoton.2016.140},
  doi = {10.1038/nphoton.2016.140}
}
"Attosecond lighthouses in gases: A theoretical and numerical study"
Auguste T, Gobert O, Ruchon T et Quere F, Phys. Rev. A., Mar, 2016. Vol. 93, pp. 033825. American Physical Society, (2016).
Abstract: We present an extensive theoretical and numerical study of the attosecond lighthouse effect in gases. We study how this scheme impacts the spatiotemporal structure of the driving laser field all along the generation medium, and show that this can modify the phase matching relation governing high-harmonic generation (HHG) in gases. We then present a set of numerical simulations performed to test the robustness of the effect against variations of HHG parameters, and to identify possible solutions for relaxing the constraint on the driving laser pulse duration. We thus demonstrate that the lighthouse effect can actually be achieved with laser pulses consisting of up to ~8 optical periods available from current lasers without postcompression, for instance by using an appropriate combination of 800- and 1600-nm wavelength fields.
BibTeX:
@article{PhysRevA.93.033825,
  author = {Auguste, T. and Gobert, O. and Ruchon, T. and Quere, F.},
  title = {Attosecond lighthouses in gases: A theoretical and numerical study},
  journal = {Phys. Rev. A},
  publisher = {American Physical Society},
  year = {2016},
  volume = {93},
  pages = {033825},
  url = {http://link.aps.org/doi/10.1103/PhysRevA.93.033825},
  doi = {10.1103/PhysRevA.93.033825}
}
"Vacuum laser acceleration of relativistic electrons using plasma mirror injectors"
Thevenet M, Leblanc A, Kahaly S, Vincenti H, Vernier A, Quere F et Faure J, Nat Phys., April, 2016. Vol. 12(4), pp. 355-360. Nature Publishing Group, (2016).
Abstract: Accelerating particles to relativistic energies over very short distances using lasers has been a long-standing goal in physics. Among the various schemes proposed for electrons, vacuum laser acceleration has attracted considerable interest and has been extensively studied theoretically because of its appealing simplicity: electrons interact with an intense laser field in vacuum and can be continuously accelerated, provided they remain at a given phase of the field until they escape the laser beam. But demonstrating this effect experimentally has proved extremely challenging, as it imposes stringent requirements on the conditions of injection of electrons in the laser field. Here, we solve this long-standing experimental problem by using a plasma mirror to inject electrons in an ultraintense laser field, and obtain clear evidence of vacuum laser acceleration. With the advent of petawatt lasers, this scheme could provide a competitive source of very high charge (nC) and ultrashort relativistic electron beams.
BibTeX:
@article{Thevenet2016,
  author = {Thevenet, M. and Leblanc, A. and Kahaly, S. and Vincenti, H. and Vernier, A. and Quere, F. and Faure, J.},
  title = {Vacuum laser acceleration of relativistic electrons using plasma mirror injectors},
  journal = {Nat Phys},
  publisher = {Nature Publishing Group},
  year = {2016},
  volume = {12},
  number = {4},
  pages = {355--360},
  url = {http://www.nature.com/nphys/journal/v12/n4/full/nphys3597.html},
  doi = {10.1038/nphys3597}
}
"Localization of ionization-induced trapping in a laser wakefield accelerator using a density down-ramp"
Hansson, M., Audet, T. L., Ekerfelt, H., Aurand, B., González, I. G., Desforges, F. G., Davoine, X., Maitrallain, A., Reymond, S., Monot, P., Persson, A., Dobosz Dufrénoy, S. D., Wahlström, C., Cros, B. & Lundh, O , Plasma Physics and Controlled Fusion. vol. 58(5) p. 055009 , (2016).
Abstract: We report on a study on controlled trapping of electrons, by field ionization of nitrogen ions, in laser wakefield accelerators in variable length gas cells. In addition to ionization-induced trapping in the density plateau inside the cells, which results in wide, but stable, electron energy spectra, a regime of ionization-induced trapping localized in the density down-ramp at the exit of the gas cells, is found. The resulting electron energy spectra are peaked, with 10% shot-to-shot fluctuations in peak energy. Ionization-induced trapping of electrons in the density down-ramp is a way to trap and accelerate a large number of electrons, thus improving the efficiency of the laser-driven wakefield acceleration.
BibTeX:
@ARTICLE{Hansson2016,
  author = {Hansson, M and Audet, T L and Ekerfelt, H and Aurand, B and González,
	I Gallardo and Desforges, F G and Davoine, X and Maitrallain, A and
	Reymond, S and Monot, P and Persson, A and Dufrénoy, S Dobosz and
	Wahlström, C-G and Cros, B and Lundh, O},
  title = {Localization of ionization-induced trapping in a laser wakefield
	accelerator using a density down-ramp},
  journal = {Plasma Physics and Controlled Fusion},
  year = {2016},
  volume = {58},
  pages = {055009--},
  number = {5},
  abstract = {We report on a study on controlled trapping of electrons, by field
	ionization of nitrogen ions, in laser wakefield accelerators in variable
	length gas cells. In addition to ionization-induced trapping in the
	density plateau inside the cells, which results in wide, but stable,
	electron energy spectra, a regime of ionization-induced trapping
	localized in the density down-ramp at the exit of the gas cells,
	is found. The resulting electron energy spectra are peaked, with
	10% shot-to-shot fluctuations in peak energy. Ionization-induced
	trapping of electrons in the density down-ramp is a way to trap and
	accelerate a large number of electrons, thus improving the efficiency
	of the laser-driven wakefield acceleration.},
  issn = {0741-3335},
  owner = {jubera},
  timestamp = {2016.03.25},
  url = {http://stacks.iop.org/0741-3335/58/i=5/a=055009}
}
"Investigation of ionization-induced electron injection in a wakefield driven by laser inside a gas cell"
Audet TL, Hansson M, Lee P, Desforges FG, Maynard G, Dobosz Dufrénoy S, Lehe R, Vay J-L, Aurand B, Persson A, Gallardo González I, Maitrallain A, Monot P, Wahlström C-G, Lundh O et Cros B, , Physics of Plasmas. Vol. 23(2), pp. 023110, (2016).
Abstract: Ionization-induced electron injection was investigated experimentally by focusing a driving laser pulse with a maximum normalized potential of 1.2 at different positions along the plasma density profile inside a gas cell, filled with a gas mixture composed of . Changing the laser focus position relative to the gas cell entrance controls the accelerated electron bunch properties, such as the spectrum width, maximum energy, and acceleratedcharge. Simulations performed using the 3D particle-in-cell code WARP with a realistic density profile give results that are in good agreement with the experimental ones. The interest of this regime for optimizing the bunch charge in a selected energy window is discussed.
BibTeX:
@article{Audet2016,
  author = {Audet, T. L. and Hansson, M. and Lee, P. and Desforges, F. G. and Maynard, G. and Dobosz Dufrenoy, S. and Lehe, R. and Vay, J.-L. and Aurand, B. and Persson, A. and Gallardo González, I. and Maitrallain, A. and Monot, P. and Wahlström, C.-G. and Lundh, O. and Cros, B.},
  title = {Investigation of ionization-induced electron injection in a wakefield driven by laser inside a gas cell},
  journal = {Physics of Plasmas},
  year = {2016},
  volume = {23},
  number = {2},
  pages = {023110},
  url = {http://scitation.aip.org/content/aip/journal/pop/23/2/10.1063/1.4942033}
}
"Electron Acceleration by Relativistic Surface Plasmons in Laser-Grating Interaction"
Fedeli L, Sgattoni A, Cantono G, Garzella D, Réau F, Prencipe I, Passoni M, Raynaud M, Květoň M, Proska J, Macchi A et Ceccotti T, Phys. Rev. Lett., Jan, 2016. Vol. 116, pp. 015001. American Physical Society - (2016).
Abstract: The generation of energetic electron bunches by the interaction of a short, ultraintense (I>1019 W/cm2) laser pulse with “grating” targets has been investigated in a regime of ultrahigh pulse-to-prepulse contrast (1012). For incidence angles close to the resonant condition for surface plasmon excitation, a strong electron emission was observed within a narrow cone along the target surface, with energy spectra peaking at 5-8 MeV and total charge of ~ 100 pC . Both the energy and the number of emitted electrons were strongly enhanced with respect to simple flat targets. The experimental data are closely reproduced by three-dimensional particle-in-cell simulations, which provide evidence for the generation of relativistic surface plasmons and for their role in driving the acceleration process. Besides the possible applications of the scheme as a compact, ultrashort source of MeV electrons, these results are a step forward in the development of high-field plasmonics.
BibTeX:
@article{PhysRevLett.116.015001,
  author = {Fedeli, L. and Sgattoni, A. and Cantono, G. and Garzella, D. and Reau, F. and Prencipe, I. and Passoni, M. and Raynaud, M. and Kveton, M. and Proska, J. and Macchi, A. and Ceccotti, T.},
  title = {Electron Acceleration by Relativistic Surface Plasmons in Laser-Grating Interaction},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2016},
  volume = {116},
  pages = {015001},
  url = {http://link.aps.org/doi/10.1103/PhysRevLett.116.015001},
  doi = {10.1103/PhysRevLett.116.015001}
}
"Detailed analysis of the effects of stencil spatial variations with arbitrary high-order finite-difference Maxwell solver"
Vincenti H et Vay J-L, Computer Physics Communications., March, 2016. Vol. 200, pp. 147-167, (2016).
Abstract: Very high order or pseudo-spectral Maxwell solvers are the method of choice to reduce discretization effects (e.g. numerical dispersion) that are inherent to low order Finite-Difference Time-Domain (FDTD) schemes. However, due to their large stencils, these solvers are often subject to truncation errors in many electromagnetic simulations. These truncation errors come from non-physical modifications of Maxwell’s equations in space that may generate spurious signals affecting the overall accuracy of the simulation results. Such modifications for instance occur when Perfectly Matched Layers (PMLs) are used at simulation domain boundaries to simulate open media. Another example is the use of arbitrary order Maxwell solver with domain decomposition technique that may under some condition involve stencil truncations at subdomain boundaries, resulting in small spurious errors that do eventually build up. In each case, a careful evaluation of the characteristics and magnitude of the errors resulting from these approximations, and their impact at any frequency and angle, requires detailed analytical and numerical studies. To this end, we present a general analytical approach that enables the evaluation of numerical errors of fully three-dimensional arbitrary order finite-difference Maxwell solver, with arbitrary modification of the local stencil in the simulation domain. The analytical model is validated against simulations of domain decomposition technique and PMLs, when these are used with very high-order Maxwell solver, as well as in the infinite order limit of pseudo-spectral solvers. Results confirm that the new analytical approach enables exact predictions in each case. It also confirms that the domain decomposition technique can be used with very high-order Maxwell solvers and a reasonably low number of guard cells with negligible effects on the whole accuracy of the simulation.
BibTeX:
@article{,
  author = {Vincenti, H. and Vay, J.-L.},
  title = {Detailed analysis of the effects of stencil spatial variations with arbitrary high-order finite-difference Maxwell solver},
  journal = {Computer Physics Communications},
  year = {2016},
  volume = {200},
  pages = {147--167},
  url = {http://www.sciencedirect.com/science/article/pii/S0010465515004208}
}
"An efficient and portable SIMD algorithm for charge/current deposition in Particle-In-Cell codes"
Vincenti H., Lehe R, Sasanka R et Vay J-L. ArXiv e-prints., (2016).
Abstract: In current computer architectures, data movement (from die to network) is by far the most energy consuming part of an algorithm (10pJ/word on-die to 10,000pJ/word on the network). To increase memory locality at the hardware level and reduce energy consumption related to data movement, future exascale computers tend to use more and more cores on each compute nodes ("fat nodes") that will have a reduced clock speed to allow for efficient cooling. To compensate for frequency decrease, machine vendors are making use of long SIMD instruction registers that are able to process multiple data with one arithmetic operator in one clock cycle. SIMD register length is expected to double every four years. As a consequence, Particle-In-Cell (PIC) codes will have to achieve good vectorization to fully take advantage of these upcoming architectures. In this paper, we present a new algorithm that allows for efficient and portable SIMD vectorization of current/charge deposition routines that are, along with the field gathering routines, among the most time consuming parts of the PIC algorithm. Our new algorithm uses a particular data structure that takes into account memory alignement constraints and avoids gather/scatter instructions that can significantly affect vectorization performances on current CPUs. The new algorithm was successfully implemented in the 3D skeleton PIC code PICSAR and tested on Haswell Xeon processors (AVX2-256 bits wide data registers). Results show a factor of ×2 to ×2.5 speed-up in double precision for particle shape factor of order 1 to 3. The new algorithm can be applied as is on future KNL (Knights Landing) architectures that will include AVX-512 instruction sets with 512 bits register lengths (8 doubles/16 singles).
BibTeX:
@article{Vincenti2016Bis,
  author = {VVincenti, H., and Lehe, R. and Sasanka, R. and  Vay, J-L.},
  title = {An efficient and portable SIMD algorithm for charge/current deposition in Particle-In-Cell codes},
  journal = {ArXiv e-prints},
  year = {2016},
  url = {http://adsabs.harvard.edu/abs/2016arXiv160102056V}
}
"Ptychographic measurements of ultrahigh-intensity laser-plasma interactions"
Leblanc A, Monchoce S, Bourassin-Bouchet C, Kahaly S et Quere F, Nat Phys., December, 2015. Vol. advance online publication, pp. -. Nature Publishing Group. (2016)
Abstract: The extreme intensities now delivered by femtosecond lasers make it possible to drive and control relativistic motion of charged particles with light, opening a path to compact particle accelerators and coherent X-ray sources. Accurately characterizing the dynamics of ultrahigh-intensity laser-plasma interactions as well as the resulting light and particle emissions is an essential step towards such achievements. This remains a considerable challenge, as the relevant scales typically range from picoseconds to attoseconds in time, and from micrometres to nanometres in space. In these experiments, owing to the extreme prevalent physical conditions, measurements can be performed only at macroscopic distances from the targets, yielding only partial information at these microscopic scales. This letter presents a major advance by applying the concepts of ptychography to such measurements, and thus retrieving microscopic information hardly accessible until now. This paves the way to a general approach for the metrology of extreme laser-plasma interactions on very small spatial and temporal scales.
BibTeX:
@article{Leblanc2015,
  author = {Leblanc, A. and Monchoce, S. and Bourassin-Bouchet, C. and Kahaly, S. and Quere, F.},
  title = {Ptychographic measurements of ultrahigh-intensity laser-plasma interactions},
  journal = {Nat Phys},
  publisher = {Nature Publishing Group},
  year = {2015},
  volume = {advance online publication},
  pages = {--},
  url = {http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3596.html},
  doi = {10.1038/nphys3596}
}
2015
"Enhanced electron acceleration via ultra-intense laser interaction with structured targets"
Fedeli L, Sgattoni A, Cantono G, Prencipe I, Passoni M, Klimo O, Proska J, Macchi A et Ceccotti T, SPIE Vol. 9514, pp. 95140R-95140R-8, (2015).
Abstract: The generation of energetic electrons by the interaction of a short laser pulse with solid “grating” targets, having a periodic groove on the irradiated surface, has been investigated in a regime of ultrahigh contrast (1012) and relativistically strong intensity (> 1019W/cm2). A strong enhancement of both the energy and number of electrons emitted from the target, with respect to at targets, has been observed for incidence angles close to the resonant condition for surface wave excitation. In particular we identified bunches of electrons with energies exceeding 10 MeV which are emitted in a direction close to the target surface. The experimental results are well reproduced by a three-dimensional particle-in-cell simulation, which confirms the dominant role of the surface wave in accelerating the electrons. These results are a step forward the development of high field plasmonics for a number of applications. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
BibTeX:
@inproceedings{Fideli2015,
  author = {Fedeli, Luca and Sgattoni, Andrea and Cantono, Giada and Prencipe, I. and Passoni, M. and Klimo, O. and Proska, J. and Macchi, Andrea and Ceccotti, T.},
  title = {Enhanced electron acceleration via ultra-intense laser interaction with structured targets},
  year = {2015},
  volume = {9514},
  pages = {95140R--95140R-8},
  url = {http://dx.doi.org/10.1117/12.2178816},
  doi = {10.1117/12.2178816}
}
"Spatio-temporal light springs: extended encoding of orbital angular momentum in ultrashort pulses"
Pariente G and Quéré F, In Optics Letters. Vol. 40(9), pp. 2037-2040. OSA. (2015).
Abstract: We introduce a new class of spatio-temporally coupled ultrashort laser beams, which are obtained by superimposing Laguerre-Gauss beams whose azimuthal mode index is correlated to their frequency. These beams are characterized by helical structures for their phase and intensity profiles, which both encode the orbital angular momentum carried by the light. They can easily be engineered in the optical range, and are naturally produced at shorter wavelengths when attosecond pulses are generated by intense femtosecond Laguerre-Gauss laser beams. These spatio-temporal "light springs" will allow for the transfer of the orbital angular momentum to matter by stimulated Raman scattering.
BibTeX:
@article{Pariente2015,
  author = {Pariente, G. and Quéré, F.},
  title = {Spatio-temporal light springs: extended encoding of orbital angular momentum in ultrashort pulses},
  booktitle = {Optics Letters},
  journal = {Opt. Lett.},
  publisher = {OSA},
  year = {2015},
  volume = {40},
  number = {9},
  pages = {2037--2040},
  url = {http://ol.osa.org/abstract.cfm?URI=ol-40-9-2037},
  doi = {10.1364/OL.40.002037}
}
"Analysis of electron injection in Laser Wakefield Acceleration using betatron emission in capillary tubes"
Desforges FG, Paradkar BS, Hansson M, Audet TL, Ju J, Gallardo-González I, Aurand B, Lee P, Senje L, Persson A, Dobosz Dufrénoy S, Lundh O, Maynard G, Monot P, Vay JL, Wahlström C-G and Cros B, Proc. SPIE 9514, Laser Acceleration of Electrons, Protons, and Ions III; and Medical Applications of Laser-Generated Beams of Particles III, 95140Z (May 14, 2015).
Abstract: The dynamics of ionization-induced electron injection in the high density (~ 1:2 * 1019cm-3) regime of Laser Wakefield Acceleration (LWFA) was investigated by analyzing betatron X-ray emission inside dielectric capillary tubes. A comparative study of the electron and betatron X-ray properties was performed for both self-injection and ionization-induced injection. Direct experimental evidence of early onset of ionization-induced injection into the plasma wave was obtained by mapping the X-ray emission zone inside the plasma. Particle-In-Cell (PIC) simulations showed that the early onset of ionization-induced injection, due to its lower trapping threshold, suppresses self-injection of electrons. An increase of X-ray fluence by at least a factor of two was observed in the case of ionization-induced injection due to an increased trapped charge compared to self-injection mechanism.
BibTeX:
@inproceedings{Desforges2015,
  author = {Desforges, F. G. and Paradkar, B. S. and Hansson, M. and Audet, T. L. and Ju, J. and Gallardo-González , I. and Aurand, B. and Lee, P. and Senje, L. and Persson, A. and Dobosz Dufrénoy, S. and Lundh, O. and Maynard, G. and Monot, P. and Vay, J. L. and Wahlström , C.-G. and Cros, B.},
  title = {Analysis of  electron injection in Laser Wakefield Acceleration using betatron emission in capillary tubes},
  year = {2015},
  volume = {9514},
  pages = {95140Z--95140Z-11},
  url = {http://dx.doi.org/10.1117/12.2178654},
  doi = {10.1117/12.2178654}
}
"Design and current progress of the Apollon 10 PW project"
Zou JP, Le Blanc C, Papadopoulos DN, Chériaux G, Georges P, Mennerat G, Druon F, Lecherbourg L, Pellegrina A, Ramirez P, Giambruno F, Fréneaux A, Leconte F, Badarau D, Boudenne JM, Fournet D, Valloton T, Paillard JL, Veray JL, Pina M, Monot P, Chambaret JP, Martin P, Mathieu F, Audebert P et Amiranoff F, High Power Laser Science and Engineering. Vol. 3, pp. e2. Cambridge University Press, (2015).
Abstract: The objective of the Apollon project is the generation of 10 PW peak power pulses of 15 fs at 1 shot/minute. In this paper the Apollon facility design, the technological challenges and the current progress of the project will be presented.
BibTeX:
@article{Zou2015,
  author = {Zou, J. P. and Le Blanc, C. and Papadopoulos, D. N. and Chriaux, G. and Georges, P. and Mennerat, G. and Druon, F. and Lecherbourg, L. and Pellegrina, A. and Ramirez, P. and Giambruno, F. and Frneaux, A. and Leconte, F. and Badarau, D. and Boudenne, J. M. and Fournet, D. and Valloton, T. and Paillard, J. L. and Veray, J. L. and Pina, M. and Monot, P. and Chambaret, J. P. and Martin, P. and Mathieu, F. and Audebert, P. and Amiranoff, F.},
  title = {Design and current progress of the Apollon10PWproject},
  journal = {High Power Laser Science and Engineering},
  publisher = {Cambridge University Press},
  year = {2015},
  volume = {3},
  pages = {e2},
  edition = {2015/01/23},
  url = {https://www.cambridge.org/core/article/design-and-current-progress-of-the-apollon-10-pw-project/1595DB33A434A0BE420BD042D7C2D725},
  doi = {10.1017/hpl.2014.41}
}
2014
"Dual spectral-band interferometry for spatio-temporal characterization of high-power femtosecond lasers"
Gallet V, Kahaly S, Gobert O and Quéré F, In Optics Letters. Vol. 39(16), pp. 4687-4690. OSA. (2014).
Abstract: We present and demonstrate a technique called RED-SEA TADPOLE for the spatio-temporal characterization of high peak power femtosecond lasers. It retains the basic principle of an existing method, where a scanning monomode fiber is utilized in an interferometric scheme to measure the spectral amplitude and phase at all points across an ultrashort laser beam. We combine this approach with dual spectral-band interferometry, to correct for all phase errors occurring in this interferometer, thus allowing for the simultaneous measurement of the beam wavefront and pulse front in a collimated beam of large diameter. The generic phase correction procedure implemented here can also be extended to other fiber optic device applications sensitive to phase fluctuations.
BibTeX:
@article{Gallet2014,
  author = {Gallet, V. and Kahaly, S. and Gobert, O. and Quéré, F.},
  title = {Dual spectral-band interferometry for spatio-temporal characterization of high-power femtosecond lasers},
  booktitle = {Optics Letters},
  journal = {Opt. Lett.},
  publisher = {OSA},
  year = {2014},
  volume = {39},
  number = {16},
  pages = {4687--4690},
  url = {http://ol.osa.org/abstract.cfm?URI=ol-39-16-4687},
  doi = {10.1364/OL.39.004687}
}
Fuchs J, Gonoskov A, Nakatsutsumi M, Nazarov W, Quéré F, Sergeev A et Yan X (2014), "Plasma devices for focusing extreme light pulses", The European Physical Journal Special Topics. Vol. 223(6), pp. 1169-1173.
Abstract: Since the inception of the laser, there has been a constant push toward increasing the laser peak intensity, as this has lead to opening the exploration of new territories, and the production of compact sources of particles and radiation with unprecedented characteristics. However, increasing the peak laser intensity is usually performed by enhancing the produced laser properties, either by lowering its duration or increasing its energy, which involves a great level of complexity for the laser chain, or comes at great cost. Focusing tightly is another possibility to increase the laser intensity, but this comes at the risk of damaging the optics with target debris, as it requires their placement in close proximity to the interaction region. Plasma devices are an attractive, compact alternative to tightly focus extreme light pulses and further increase the final laser intensity.
BibTeX:
@article{Fuchs2014,
  author = {Fuchs, J. and Gonoskov, A.A. and Nakatsutsumi, M. and Nazarov, W. and Quéré, F. and Sergeev, A.M. and Yan, X.Q.},
  title = {Plasma devices for focusing extreme light pulses},
  journal = {The European Physical Journal Special Topics},
  year = {2014},
  volume = {223},
  number = {6},
  pages = {1169--1173},
  url = {http://dx.doi.org/10.1140/epjst/e2014-02169-y},
  doi = {10.1140/epjst/e2014-02169-y}
}
"Optically Controlled Solid-Density Transient Plasma Gratings"
Monchocé S, Kahaly S, Leblanc A, Videau L, Combis P., Réau F, Garzella D, D'Oliveira P, Martin P and Quéré F, Phys. Rev. Lett., Vol. 112(14), pp. 145008-. American Physical Society. April, (2014).
Abstract: A general approach for optically controlled spatial structuring of overdense plasmas generated at the surface of initially plain solid targets is presented. We demonstrate it experimentally by creating sinusoidal plasma gratings of adjustable spatial periodicity and depth, and study the interaction of these transient structures with an ultraintense laser pulse to establish their usability at relativistically high intensities. We then show how these gratings can be used as a "spatial ruler" to determine the source size of the high-order harmonic beams produced at the surface of an overdense plasma. These results open new directions both for the metrology of laser-plasma interactions and the emerging field of ultrahigh intensity plasmonics.
BibTeX:
@article{Monchocé2014,
  author = {Monchocé, S. and Kahaly, S. and Leblanc, A. and Videau, L. and Combis,P., and Réau, F. and Garzella, D. and D'Oliveira, P. and Martin, Ph. and Quéré, F.},
  title = {Optically Controlled Solid-Density Transient Plasma Gratings},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2014},
  volume = {112},
  number = {14},
  pages = {145008--},
  url = {http://link.aps.org/doi/10.1103/PhysRevLett.112.145008},
  doi = {10.1103/PhysRevLett.112.145008}
}
"Enhanced stability of laser wakefield acceleration using dielectric capillary tubes"
Hansson M, Senje L, Persson A, Lundh O, Wahlström C-G, Desforges FG, Ju J, Audet TL, Cros B, Dobosz Dufrénoy S et Monot P, Phys. Rev. ST Accel. Beams., Mar, 2014. Vol. 17, pp. 031303. American Physical Society, (2014).
Abstract: The stability of beams of laser wakefield accelerated electrons in dielectric capillary tubes is experimentally investigated. These beams are found to be more stable in charge and pointing than the corresponding beams of electrons accelerated in a gas jet. Electron beams with an average charge of 43 pC and a standard deviation of 14% are generated. The fluctuations in charge are partly correlated to fluctuations in laser pulse energy. The pointing scatter of the electron beams is measured to be as low as 0.8 mrad (rms). High laser beam pointing stability improved the stability of the electron beams.
BibTeX:
@article{PhysRevSTAB.17.031303,
  author = {Hansson, M. and Senje, L. and Persson, A. and Lundh, O. and Wahlström, C-G. and Desforges, F. G. and Ju, J. and Audet, T. L. and Cros, B. and Dobosz Dufrénoy, S. and Monot, P.},
  title = {Enhanced stability of laser wakefield acceleration using dielectric capillary tubes},
  journal = {Phys. Rev. ST Accel. Beams},
  publisher = {American Physical Society},
  year = {2014},
  volume = {17},
  pages = {031303},
  url = {http://link.aps.org/doi/10.1103/PhysRevSTAB.17.031303},
  doi = {10.1103/PhysRevSTAB.17.031303}
}
"Applications of ultrafast wavefront rotation in highly nonlinear optics"
Quéré F, Vincenti H, Borot A, Monchocé S., Hammond TJ, Kim KT, Wheeler JA, Zhang C, Ruchon T, Auguste T, Hergott JF, Villeneuve DM, Corkum PB and Lopez-Martens R, Journal of Physics B: Atomic, Molecular and Optical Physics. Vol. 47(12), pp. 124004-. (2014).
Abstract: This paper provides an overview of ultrafast wavefront rotation of femtosecond laser pulses and its various applications in highly nonlinear optics, focusing on processes that lead to the generation of high-order harmonics and attosecond pulses. In this context, wavefront rotation can be exploited in different ways, to obtain new light sources for time-resolved studies, called 'attosecond lighthouses', to perform time-resolved measurements of nonlinear optical processes, using 'photonic streaking', or to track changes in the carrier-envelope relative phase of femtosecond laser pulses. The basic principles are explained qualitatively from different points of view, the experimental evidence obtained so far is summarized, and the perspectives opened by these effects are discussed.
BibTeX:
@article{Quéré2014,
  author = {Quéré, F and Vincenti, H and Borot, A and Monchocé, S., and Hammond, T J and Kim, Kyung Taec and Wheeler, J A and Zhang, Chunmei and Ruchon, T and Auguste, T and Hergott, J F and Villeneuve, D M and Corkum, P B and Lopez-Martens, R},
  title = {Applications of ultrafast wavefront rotation in highly nonlinear optics},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  year = {2014},
  volume = {47},
  number = {12},
  pages = {124004--},
  url = {http://stacks.iop.org/0953-4075/47/i=12/a=124004},
  doi = {10.1088/0953-4075/47/12/124004}
}
"Dynamics of ionization-induced electron injection in the high density regime of laser wakefield acceleration"
Desforges FG, Paradkar BS, Hansson M, Ju J, Senje L, Audet TL, Persson A, Dobosz-Dufrénoy S, Lundh O, Maynard G, Monot P, Vay J-L, Wahlström C-G and Cros B, Physics of Plasmas (1994-present). Vol. 21(12), pp. (2014).
Abstract: The dynamics of ionization-induced electron injection in high density (~1.2 * 1019 cm-3) regime of laser wakefield acceleration is investigated by analyzing the betatron X-ray emission. In such high density operation, the laser normalized vector potential exceeds the injection-thresholds of both ionization-injection and self-injection due to self-focusing. In this regime, direct experimental evidence of early on-set of ionization-induced injection into the plasma wave is given by mapping the X-ray emission zone inside the plasma. Particle-In-Cell simulations show that this early on-set of ionization-induced injection, due to its lower trapping threshold, suppresses the trapping of self-injected electrons. A comparative study of the electron and X-ray properties is performed for both self-injection and ionization-induced injection. An increase of X-ray fluence by at least a factor of two is observed in the case of ionization-induced injection due to increased trapped charge compared to self-injection mechanism.
BibTeX:
@article{:/content/aip/journal/pop/21/12/10.1063/1.4903845,
  author = {Desforges, F. G. and Paradkar, B. S. and Hansson, M. and Ju, J. and Senje, L. and Audet, T. L. and Persson, A. and Dobosz-Dufrénoy, S. and Lundh, O. and Maynard, G. and Monot, P. and Vay, J.-L. and Wahlström, C.-G. and Cros, B.},
  title = {Dynamics of ionization-induced electron injection in the high density regime of laser wakefield acceleration},
  journal = {Physics of Plasmas (1994-present)},
  year = {2014},
  volume = {21},
  number = {12},
  pages = {-},
  url = {http://scitation.aip.org/content/aip/journal/pop/21/12/10.1063/1.4903845},
  doi = {10.1063/1.4903845}
}
"Energetic ions at moderate laser intensities using foam-based multi-layered targets"
Passoni M, Zani A, Sgattoni A, Dellasega D, Macchi A, Prencipe I, Floquet V, Martin P, Liseykina TV and Ceccotti T, Plasma Physics and Controlled Fusion. Vol. 56(4), pp. 045001 - (2014).
Abstract: The experimental feasibility of the laser-driven ion acceleration concept with multi-layered, foam-based targets has been investigated. Targets with the required features have been produced and characterized, exploiting the potential of the pulsed laser deposition technique. In the intensity range 1016-1017 W cm-2, they allow us to obtain maximum proton energies 2-3 times higher compared to bare solid targets, able to reach and surpass the MeV range with both low and ultrahigh contrast pulses. The results of two-dimensional particle-in-cell simulations, supporting the interpretation of the experimental results, and directions to exploit the concept also at ultrahigh intensities, are presented.
BibTeX:
@article{Passoni2014,
  author = {Passoni, M and Zani, A and Sgattoni, A and Dellasega, D and Macchi, A and Prencipe, I and Floquet, V and Martin, P and Liseykina, T V and Ceccotti, T},
  title = {Energetic ions at moderate laser intensities using foam-based multi-layered targets},
  journal = {Plasma Physics and Controlled Fusion},
  year = {2014},
  volume = {56},
  number = {4},
  pages = {045001},
  url = {http://stacks.iop.org/0741-3335/56/i=4/a=045001},
  doi = {10.1088/0741-3335/56/4/045001}
}
"Enhanced stability of laser wakefield acceleration using dielectric capillary tubes"
Hansson M, Senje L,Persson A, Lundh O, Wahlström C.G, Desforges F.G, Lu J, Audet TL, Cros B, Dobosz Dufrénoy S, Monot P, Phys. Rev. ST Accel. Beams - (2014).
Abstract: The stability of beams of laser wakefield accelerated electrons in dielectric capillary tubes is experimentally investigated. These beams are found to be more stable in charge and pointing than the corresponding beams of electrons accelerated in a gas jet. Electron beams with an average charge of 43 pC and a standard deviation of 14% are generated. The fluctuations in charge are partly correlated to fluctuations in laser pulse energy. The pointing scatter of the electron beams is measured to be as low as 0.8 mrad (rms). High laser beam pointing stability improved the stability of the electron beams.
BibTeX:
@article{Hansson2014,
  author = {Hansson, M. and Senje M.  Persson, A. and Lundh, O. and Wahlström, C.G.and Desforges, F.G. and Lu, J. and. Audet, T. L. and  Cros, B. and Dobosz Dufrénoy, S. and Monot},
  title = {Enhanced stability of laser wakefield acceleration using dielectric capillary tubes},
  journal = {PRST AB},
  year = {2014},
  url = {http://journals.aps.org/prstab/abstract/10.1103/PhysRevSTAB.17.031303},
  doi = {10.1103/PhysRevSTAB.17.031303}
}
"Laser plasma acceleration of electrons with multi-PW laser beams in the frame of CILEX"
Cros B, Paradkar B, Davoine X, Chancé A, Desforges F, Dobosz-Dufrénoy S, Delerue N, Ju J, Audet T, Maynard G, Lobet M, Gremillet L, Mora P, Schwindling J, Delferrière O, Bruni C, Rimbault C, Vinatier T, Di Piazza A, Grech M, Riconda C, Marquès J, Beck A, Specka A, Martin P, Monot P, Normand D, Mathieu F, Audebert P and Amiranoff F, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. La Biodola, Italie Vol. 740, pp. 27-33. Elsevier - (2014).
Abstract: Laser plasma acceleration of electrons has progressed along with advances in laser technology. It is thus expected that the development in the near-future of multi-PW-class laser and facilities will enable a vast range of scientific opportunities for laser plasma acceleration research. On one hand, high peak powers can be used to explore the extremely high intensity regime of laser wakefield acceleration, producing for example large amounts of electrons in the GeV range or generating high energy photons. On the other hand, the available laser energy can be used in the quasi-linear regime to create accelerating fields in large volumes of plasma and study controlled acceleration in a plasma stage of externally injected relativistic particles, either electrons or positrons. In the frame of the Centre Interdisciplinaire de la Lumière EXtrème (CILEX), the Apollon-10P laser will deliver two beams at the 1 PW and 10 PW levels, in ultra-short (View the MathML source) pulses, to a target area dedicated to electron acceleration studies, such as the exploration of the non-linear regimes predicted theoretically, or multi-stage laser plasma acceleration.
BibTeX:
@inproceedings{cros:in2p3-00903672,
  author = {Cros, B. and Paradkar, B.S. and Davoine, X. and Chancé, A. and Desforges, F.G. and Dobosz-Dufrénoy, S. and Delerue, N. and Ju, J. and Audet, T.L. and Maynard, G. and Lobet, M. and Gremillet, L. and Mora, P. and Schwindling, J. and Delferrière, O. and Bruni, C. and Rimbault, C. and Vinatier, T. and Di Piazza, A. and Grech, M. and Riconda, C. and Marquès, J.R. and Beck, A. and Specka, A. and Martin, Ph. and Monot, P. and Normand, D. and Mathieu, F. and Audebert, P. and Amiranoff, F.},
  editor = {Ralph Assmann, Massimo Ferrario, Jens Osterhoff, Arnd E. Specka },
  title = {Laser plasma acceleration of electrons with multi-PW laser beams in the frame of CILEX},
  booktitle = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  publisher = {Elsevier},
  year = {2014},
  volume = {740},
  pages = {27-33},
  note = {LAL/RT 13-48 },
  url = {http://hal.in2p3.fr/in2p3-00903672},
  doi = {10.1016/j.nima.2013.10.090}
}
"Reproducibility of electron beams from laser wakefield acceleration in capillary tubes"
Desforges F, Hansson M, Ju J, Senje L, Audet T, Dobosz-Dufrénoy S, Persson A, Lundh O, Wahlström C-G and Cros B, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment., In Proceedings of the first European Advanced Accelerator Concepts Workshop 2013., Vol. 740(0), pp. 54-59 - March, (2014).
Abstract: The stability of accelerated electron beams produced by self-injection of plasma electrons into the wakefield driven by a laser pulse guided inside capillary tubes is analyzed statistically in relation to laser and plasma parameters, and compared to results obtained in a gas jet. The analysis shows that reproducible electron beams are achieved with a charge of 66 pC ±11%, a FWHM beam divergence of 9 mrad ±14%, a maximum energy of 120 MeV ±10% and pointing fluctuations of 2.3 mrad using 10 mm long, 178μm diameter capillary tubes at an electron density of (10.0±1.5)*1018 cm-3. Active stabilization of the laser pointing was used and laser parameters were recorded on each shot. Although the shot-to-shot laser energy fluctuations can account for a fraction of the electrons fluctuations, gas density fluctuations are suspected to be a more important source of instability.
BibTeX:
@article{Desforges2014,
  author = {Desforges, F.G. and Hansson, M. and Ju, J. and Senje, L. and Audet, T.L. and Dobosz-Dufrénoy, S. and Persson, A. and Lundh, O. and Wahlström, C.-G. and Cros, B.},
  title = {Reproducibility of electron beams from laser wakefield acceleration in capillary tubes},
  booktitle = {Proceedings of the first European Advanced Accelerator Concepts Workshop 2013},
  journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  year = {2014},
  volume = {740},
  number = {0},
  pages = {54--59},
  url = {http://www.sciencedirect.com/science/article/pii/S0168900213014538}
}
"Ultrafast formation of hydrated electrons in water at high concentration: experimental evidence of the free electron"
Palianov P, Martin P, Quéré F and Pommeret S, Journal of Experimental and Theoretical Physics. Vol. Vol. 145 (3) - (2014).
Abstract: Using a time-resolved optical interferometric technique, we investigate the ultrafast primary events following the interaction of an ultrashort laser pulse with pure water in the TW/cm<sup>2</sup> regime. Because our method is sensitive to the quasi-instantaneous electron energy level position, we demonstrate that in contrast to the well-known low-intensity regime, where the free electrons are instantaneously captured by pre-existing traps, in this new regime of excitation, free electrons are clearly observed, exhibiting a substantial contribution in the near IR. The delayed localization is attributed to the saturation of pre-existing cavities in the liquid by the large number of the excited electron states created.
BibTeX:
@article{Palianov2014,
  author = {Palianov, P. and Martin, P.and Quéré, P. and Pommeret, S.},
  title = {ULTRAFAST FORMATION OF HYDRATED ELECTRONS IN WATER AT HIGH CONCENTRATION: EXPERIMENTAL EVIDENCE OF THE FREE ELECTRON},
  journal = {Journal of Experimental and Theoretical Physics},
  year = {2014},
  volume = {Vol. 145 (3)},
  url = {http://jetp.ac.ru/cgi-bin/e/index/r/145/3/p559?a=list}
}
"Investigation of amplitude spatio-temporal couplings at the focus of a 100 TW-25 fs laser"
Kahaly, Monchocé S, Gallet V, Gobert O, Réau F, Tcherbakoff O, D'Oliveira P. Martin P and Quéré F, Applied Physics Letters - (2014).
Abstract: We address the on target focal spot spatio-temporal features of an ultrashort, 100 TW class laser chain by using spectrally resolved imaging diagnostics. The observed spatio-spectral images, which we call rotating imaging spectrographs, are obtained single shot to reveal the essential information about the spatio-temporal couplings. We observe nontrivial effects in the focal plane due to compressor defects which significantly affect the maximum on target intensity. This diagnostic might become an essential tool for improving compressor alignment in many upcoming multi-petawatt short pulse laser facilities.
BibTeX:
@article{Kahaly2014,
  author = {Kahaly, and Monchocé, S. and Gallet, V. and Gobert, O. and Réau, F. and Tcherbakoff, O. and D'Oliveira, P. Martin, P. and Quéré, F},
  title = {Investigation of amplitude spatio-temporal couplings at the focus of a 100 TW-25 fs laser},
  journal = {Applied Physics Letters},
  year = {2014},
  url = {http://scitation.aip.org/content/aip/journal/apl/104/5/10.1063/1.4863828}
}
"Optical properties of relativistic plasma mirrors"
Vincenti H, Monchocé S., Kahaly S, Bonnaud G, Martin P and Quéré F, Nat Commun.,Vol. 5, pp. -. Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. - March, (2014).
Abstract: The advent of ultrahigh-power femtosecond lasers creates a need for an entirely new class of optical components based on plasmas. The most promising of these are known as plasma mirrors, formed when an intense femtosecond laser ionizes a solid surface. These mirrors specularly reflect the main part of a laser pulse and can be used as active optical elements to manipulate its temporal and spatial properties. Unfortunately, the considerable pressures exerted by the laser can deform the mirror surface, unfavourably affecting the reflected beam and complicating, or even preventing, the use of plasma mirrors at ultrahigh intensities. Here we derive a simple analytical model of the basic physics involved in laser-induced deformation of a plasma mirror. We validate this model numerically and experimentally, and use it to show how such deformation might be mitigated by appropriate control of the laser phase.
BibTeX:
@article{Vincenti2014,
  author = {Vincenti, H. and Monchocé, S., and Kahaly, S. and Bonnaud, G. and Martin, Ph. and Quéré,  F.},
  title = {Optical properties of relativistic plasma mirrors},
  journal = {Nat Commun},
  publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
  year = {2014},
  volume = {5},
  pages = {--},
  url = {http://dx.doi.org/10.1038/ncomms4403},
  doi = {10.1038/ncomms4403}
}
2013
"Evidence of Resonant Surface-Wave Excitation in the Relativistic Regime through Measurements of Proton Acceleration from Grating Targets"
Ceccotti T, Floquet V, Sgattoni A, Bigongiari A, Klimo O, Raynaud M, Riconda C, Heron A, Baffigi F, Labate L, Gizzi LA, Vassura L, Fuchs J, Passoni M, Kveton M, Novotny F, Possolt M, Prokupek J, Proska J, Psikal J, Stolcova L, Velyhan A, Bougeard M, D'Oliveira P, Tcherbakoff O, Reau F, Martin P and Macchi A, Phys. Rev. Lett., Vol. 111, pp. 185001. American Physical Society - Oct, (2013).
Abstract: The interaction of laser pulses with thin grating targets, having a periodic groove at the irradiated surface, has been experimentally investigated. Ultrahigh contrast (~ 1012) pulses allowed to demonstrate an enhanced laser-target coupling for the first time in the relativistic regime of ultra-high intensity > 1019 W/cm2. A maximum increase by a factor of 2.5 of the cut-off energy of protons produced by Target Normal Sheath Acceleration has been observed with respect to plane targets, around the incidence angle expected for resonant excitation of surface waves. A significant enhancement is also observed for small angles of incidence, out of resonance.
BibTeX:
@article{PhysRevLett.111.185001,
  author = {Ceccotti, T. and Floquet, V. and Sgattoni, A. and Bigongiari, A. and Klimo, O. and Raynaud, M. and Riconda, C. and Heron, A. and Baffigi, F. and Labate, L. and Gizzi, L. A. and Vassura, L. and Fuchs, J. and Passoni, M. and Kveton, M. and Novotny, F. and Possolt, M. and Prokupek, J. and Proška, J. and Pšikal, J. and Štolcová, L. and Velyhan, A. and Bougeard, M. and D'Oliveira, P. and Tcherbakoff, O. and Reau, F. and Martin, P. and Macchi, A.},
  title = {Evidence of Resonant Surface-Wave Excitation in the Relativistic Regime through Measurements of Proton Acceleration from Grating Targets},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2013},
  volume = {111},
  pages = {185001},
  url = {http://link.aps.org/doi/10.1103/PhysRevLett.111.185001},
  doi = {10.1103/PhysRevLett.111.185001}
}
"Spectral characterization of laser-driven solid-based high harmonics in the coherent wake emission regime"
Van Tilborg J, Shaw BH, Sokollik T, Rykovanov S, Leemans WP, Monchocé S, Quéré F, Martin P and Malvache A, Optics Letters, Accepted - (2013).
Abstract: Laser-produced surface high harmonic generation (SHHG) is an attractive source of extreme ultra-violet radiation due to its coherent properties and high peak power. By operating at sub-relativistic laser intensities in the coherent wake emission regime, the harmonic spectrum was experimentally studied versus laser properties. At higher laser intensities (>1017 W/cm2) a higher spectral cut-off was observed, with accompanying blue-shifting and spectral broadening of the individual orders. A model based on an expanding critical-surface provides qualitative agreement to the observations.
BibTeX:
@article{Vantilborg2013,
  author = {Van Tilborg, J. and Shaw, B. H. and Sokollik,  T. and Rykovanov, S. and Leemans, W. P. and Monchocé, S. and Quéré, F. and Martin, Ph. and Malvache,  A.},
  title = {Spectral characterization of laser-driven solid-based high harmonics in the coherent wake emission regime},
  journal = {Optics Letters, Accepted (2013)},
  year = {2013},
  url = {http://www.opticsinfobase.org/view_article.cfm?gotourl=http%3A%2F%2Fwww%2Eopticsinfobase%2Eorg%2FDirectPDFAccess%2F88B73657%2DBF18%2DD2BE%2DDA2D00F96AD4A837%5Fads192293%2Epdf%3Fda%3D1%26adsid%3D192293%26journal%3D3%26seq%3D0%26mobile%3Dno&org=}
}
"Photonic streaking of attosecond pulse trains"
Kim KT, Zhang C, Ruchon T, Hergott J-F, Auguste T, Villeneuve D.M., Corkum P.B. and Quere F, Nat Photon., Vol. 7(8), pp. 651-656. Nature Publishing Group - August, (2013).
Abstract: High harmonic radiation, produced when intense laser pulses interact with matter, is composed of a train of attosecond pulses. Individual pulses in this train carry information on ultrafast dynamics that vary from one half-optical-cycle to the next. Here, we demonstrate an all-optical photonic streaking measurement that provides direct experimental access to each attosecond pulse by mapping emission time onto propagation angle. This is achieved by inducing an ultrafast rotation of the instantaneous laser wavefront at the focus. We thus time-resolve attosecond pulse train generation, and hence the dynamics in the nonlinear medium itself. We apply photonic streaking to harmonic generation in gases and directly observe, for the first time, the influence of non-adiabatic electron dynamics and plasma formation on the generated attosecond pulse train. These experimental and numerical results also provide the first evidence of the generation of attosecond lighthouses in gases, which constitute ideal sources for attosecond pump-probe spectroscopy.
BibTeX:
@article{Kim2013,
  author = {Kim, Kyung Taec and Zhang, Chunmei and Ruchon, Thierry and Hergott, Jean-Francois and Auguste, Thierry and M., VilleneuveD. and B., CorkumP. and QuereF.},
  title = {Photonic streaking of attosecond pulse trains},
  journal = {Nat Photon},
  publisher = {Nature Publishing Group},
  year = {2013},
  volume = {7},
  number = {8},
  pages = {651--656},
  url = {http://dx.doi.org/10.1038/nphoton.2013.170},
  doi = {10.1038/nphoton.2013.170}
}
"Micro-sphere layered targets efficiency in laser driven proton acceleration"
Floquet V, Klimo O, Psikal J, Velyhan A, Limpouch J, Proska J, Novotny F, Stolcova L, Macchi A, Sgattoni A, Vassura L, Labate L, Baffigi F, Gizzi LA, Martin P and Ceccotti T, J. Appl. Phys., Vol. 114(8), pp. 083305-5. AIP - August, (2013).
Abstract: Proton acceleration from the interaction of high contrast, 25 fs laser pulses at >1019 W/cm2 intensity with plastic foils covered with a single layer of regularly packed micro-spheres has been investigated experimentally. The proton cut-off energy has been measured as a function of the micro-sphere size and laser incidence angle for different substrate thickness, and for both P and S polarization. The presence of micro-spheres with a size comparable to the laser wavelength allows to increase the proton cut-off energy for both polarizations at small angles of incidence (10°). For large angles of incidence, however, proton energy enhancement with respect to flat targets is absent. Analysis of electron trajectories in particle-in-cell simulations highlights the role of the surface geometry in the heating of electrons.
BibTeX:
@article{Floquet2013,
  author = {Floquet, V. and Klimo, O. and Psikal, J. and Velyhan, A. and Limpouch, J. and Proska, J. and Novotny, F. and Stolcova, L. and Macchi, A. and Sgattoni, A. and Vassura, L. and Labate, L. and Baffigi, F. and Gizzi, L. A. and Martin, Ph. and Ceccotti, T.},
  title = {Micro-sphere layered targets efficiency in laser driven proton acceleration},
  journal = {J. Appl. Phys.},
  publisher = {AIP},
  year = {2013},
  volume = {114},
  number = {8},
  pages = {083305--5},
  url = {http://dx.doi.org/10.1063/1.4819239},
  doi = {10.1063/1.4819239}
}
"Space- and time-resolved observation of extreme laser frequency upshifting during ultrafast-ionization"
Giulietti A, Andre A, Dobosz Dufrénoy S, Giulietti D, Hosokai T, Koester P, Kotaki H, Labate L, Levato T, Nuter R, Pathak NC, Monot P and Gizzi LA, Physics of Plasmas. Vol. 20(8), pp. 082307. AIP - (2013).
Abstract: A 65-fs, 800-nm, 2-TW laser pulse propagating through a nitrogen gas jet has been experimentally studied by 90° Thomson scattering. Time-integrated spectra of scattered light show unprecedented broadening towards the blue which exceeds 300 nm. Images of the scattering region provide for the first time a space- and time-resolved description of the process leading quite regularly to such a large upshift. The mean shifting rate was as high as δλ/δt≈Å/fs, never observed before. Interferometry shows that it occurs after partial laser defocusing. Numerical simulations prove that such an upshift is consistent with a laser-gas late interaction, when laser intensity has decreased well below relativistic values (a0 << 1) and ionization process involves most of the laser pulse. This kind of interaction makes spectral tuning of ultrashort intense laser pulses possible in a large spectral range.
BibTeX:
@article{giulietti:082307,
  author = {A. Giulietti and A. Andre and S. Dobosz Dufrénoy and D. Giulietti and T. Hosokai and P. Koester and H. Kotaki and L. Labate and T. Levato and R. Nuter and N. C. Pathak and P. Monot and L. A. Gizzi},
  title = {Space- and time-resolved observation of extreme laser frequency upshifting during ultrafast-ionization},
  journal = {Physics of Plasmas},
  publisher = {AIP},
  year = {2013},
  volume = {20},
  number = {8},
  pages = {082307},
  url = {http://link.aip.org/link/?PHP/20/082307/1},
  doi = {10.1063/1.4818602}
}
"Direct Observation of Density-Gradient Effects in Harmonic Generation from Plasma Mirrors"
Kahaly S, Monchocé S, Vincenti H, Dzelzainis T, Dromey B, Zepf M, Martin P and Quéré F , Phys. Rev. Lett., Vol. 110, pp. 175001. American Physical Society - Apr, (2013).
Abstract: High-order harmonics and attosecond pulses of light can be generated when ultraintense, ultrashort laser pulses reflect off a solid-density plasma with a sharp vacuum interface, i.e., a plasma mirror. We demonstrate experimentally the key influence of the steepness of the plasma-vacuum interface on the interaction, by measuring the spectral and spatial properties of harmonics generated on a plasma mirror whose initial density gradient scale length L is continuously varied. Time-resolved interferometry is used to separately measure this scale length.
BibTeX:
@article{PhysRevLett.110.175001,
  author = {Kahaly, S. and Monchocé, S. and Vincenti,H. and Dzelzainis, T. and Dromey, B.  and Zepf,  M. and Martin, Ph. and Quéré, F.},
  title = {Direct Observation of Density-Gradient Effects in Harmonic Generation from Plasma Mirrors},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2013},
  volume = {110},
  pages = {175001},
  url = {http://link.aps.org/doi/10.1103/PhysRevLett.110.175001},
  doi = {10.1103/PhysRevLett.110.175001}
}
"Coherent wake emission spectroscopy as a probe of steep plasma density profiles"
Malvache A, Borot A, Quéré F and Lopez-Martens R, Physical Review E., Vol. 87, pp. 035101. American Physical Society - March, (2013).
Abstract: Precise knowledge of the plasma density gradient created by an intense laser field at the surface of a solid is essential for understanding and controlling the resulting laser-plasma interaction. We present a novel experimental method for determining the scale length of such a gradient in a single shot, based on the spectral analysis of coherent wake emission by a laser-induced solid density plasma, using an analytical model of this emission process. We illustrate this approach in a pump-probe experiment, where it is used to measure the expansion velocity of a plasma into a vacuum.
BibTeX:
@article{citeulike:12177820,
  author = {Malvache, A. and Borot, A. and Quéré, F and Lopez-Martens, R.},
  title = {Coherent wake emission spectroscopy as a probe of steep plasma density profiles},
  journal = {Physical Review E},
  publisher = {American Physical Society},
  year = {2013},
  volume = {87},
  pages = {035101},
  url = {http://dx.doi.org/10.1103/physreve.87.035101},
  doi = {10.1103/physreve.87.035101}
}
"Charge Equilibrium of a Laser-Generated Carbon-Ion Beam in Warm Dense Matter"
Gauthier M, Chen SN, Levy A, Audebert P, Blancard C, Ceccotti T, Cerchez M, Doria D, Floquet V, Lamour E, Peth C, Romagnani L, Rozet J-P, Scheinder M, Shepherd R, Toncian T, Vernhet D, Willi O, Borghesi M, Faussurier G and Fuchs J, Phys. Rev. Lett., Vol. 110, pp. 135003. American Physical Society - Mar, (2013).
Abstract: Using ion carbon beams generated by high intensity short pulse lasers we perform measurements of single shot mean charge equilibration in cold or isochorically heated solid density aluminum matter. We demonstrate that plasma effects in such matter heated up to 1 eV do not significantly impact the equilibration of carbon ions with energies 0.045-0.5 MeV/nucleon. Furthermore, these measurements allow for a first evaluation of semiempirical formulas or ab initio models that are being used to predict the mean of the equilibrium charge state distribution for light ions passing through warm dense matter.
BibTeX:
@article{PhysRevLett.110.135003,
  author = {Gauthier, M. and Chen, S. N. and Levy, A. and Audebert, P. and Blancard, C. and Ceccotti, T. and Cerchez, M. and Doria, D. and Floquet, V. and Lamour, E. and Peth, C. and Romagnani, L. and Rozet, J.-P. and Scheinder, M. and Shepherd, R. and Toncian, T. and Vernhet, D. and Willi, O. and Borghesi, M. and Faussurier, G. and Fuchs, J.},
  title = {Charge Equilibrium of a Laser-Generated Carbon-Ion Beam in Warm Dense Matter},
  journal = {Phys. Rev. Lett.},
  publisher = {American Physical Society},
  year = {2013},
  volume = {110},
  pages = {135003},
  url = {http://link.aps.org/doi/10.1103/PhysRevLett.110.135003},
  doi = {10.1103/PhysRevLett.110.135003}
}
2012
"Attosecond control of collective electron motion in plasmas"
Borot A, Malvache A, Chen X, Jullien A, Geindre J-P, Audebert P, Mourou G, Quere F and Lopez-Martens R, Nature Physics., Vol. 8(5), pp. 416-421 - May, (2012).
Abstract: Today, light fields of controlled and measured waveform can be used to guide electron motion in atoms and molecules with attosecond precision. Here, we demonstrate attosecond control of collective electron motion in plasmas driven by extreme intensity (≈1018 W cm−2) light fields. Controlled few-cycle near-infrared waves are tightly focused at the interface between vacuum and a solid-density plasma, where they launch and guide subcycle motion of electrons from the plasma with characteristic energies in the multi-kiloelectronvolt range-two orders of magnitude more than has been achieved so far in atoms and molecules. The basic spectroscopy of the coherent extreme ultraviolet radiation emerging from the light-plasma interaction allows us to probe this collective motion of charge with sub-200 as resolution. This is an important step towards attosecond control of charge dynamics in laser-driven plasma experiments.
BibTeX:
@article{Borot2012,
  author = {Borot, Antonin and Malvache, Arnaud and Chen, Xiaowei and Jullien, Aurelie and Geindre, Jean-Paul and Audebert, Patrick and Mourou, Gerard and Quere, Fabien and Lopez-Martens, Rodrigo},
  title = {Attosecond control of collective electron motion in plasmas},
  journal = {Nature Physics},
  year = {2012},
  volume = {8},
  number = {5},
  pages = {416--421},
  doi = {10.1038/NPHYS2269}
}
"First measurements of laser-accelerated proton induced luminescence"
Floquet V, Ceccotti T, Dobosz Dufrénoy S, Bonnaud G, Gremillet L, Monot P and Martin P, Physics of Plasmas., Vol. 19(9), pp. 094501 - September, (2012).
Abstract: We present our first results about laser-accelerated proton induced luminescence in solids. In the first part, we describe the optimization of the proton source as a function of the target thickness as well as the laser pulse duration and energy. Due to the ultra high contrast ratio of our laser beam, we succeeded in using targets ranging from the micron scale down to nanometers thickness. The two optimal thicknesses we put in evidence are in good agreement with numerical simulations. Laser pulse duration shows a small influence on proton maximum energy, whereas the latter turns out to vary almost linearly as a function of laser energy. Thanks to this optimisation work, we have been able to acquire images of the proton energy deposition in a solid scintillator.
BibTeX:
@article{Floquet2012,
  author = {Floquet, V. and Ceccotti, T. and Dobosz Dufrénoy, S. and Bonnaud, G. and Gremillet, L. and Monot, P. and Martin, Ph.},
  title = {First measurements of laser-accelerated proton induced luminescence},
  journal = {Physics of Plasmas},
  year = {2012},
  volume = {19},
  number = {9},
  pages = {094501},
  doi = {10.1063/1.4753939}
}
"Attosecond Lighthouses: How To Use Spatiotemporally Coupled Light Fields To Generate Isolated Attosecond Pulses"
Vincenti H and Quere F, Physical Review Letters., Vol. 108(11), pp. 113904 - March, (2012).
Abstract: Under the effect of even simple optical components, the spatial properties of femtosecond laser beams can vary over the duration of the light pulse. We show how using such spatiotemporally coupled light fields in high harmonic generation experiments (e.g., in gases or dense plasmas) enables the production of attosecond lighthouses, i.e., sources emitting a collection of angularly well-separated light beams, each consisting of an isolated attosecond pulse. This general effect opens the way to a new generation of light sources, particularly suitable for attosecond pump-probe experiments, and provides a new tool for ultrafast metrology, for instance, giving direct access to fluctuations of the carrier-envelope relative phase of even the most intense ultrashort lasers.
BibTeX:
@article{Vincenti2012c,
  author = {Vincenti, H. and Quere, F.},
  title = {Attosecond Lighthouses: How To Use Spatiotemporally Coupled Light Fields To Generate Isolated Attosecond Pulses},
  journal = {Physical Review Letters},
  year = {2012},
  volume = {108},
  number = {11},
  pages = {113904},
  doi = {10.1103/PhysRevLett.108.113904}
}
"Attosecond lighthouses"
Vincenti H, Wheeler J, Monchoce S, Borot A, Malvache A, Lopez-Martens R and Quere F, 2012 Conference on Lasers and Electro-Optics (CLEO). , pp. IEEE Photonics Soc. - (2012).
Abstract: We show how to use spatio-temporally coupled light fields to generate isolated attosecond pulses. This general effect provides an ideal scheme for attosecond pump-probe experiments, and constitutes a powerful new tool for ultrafast metrology.
BibTeX:
@article{Vincenti2012,
  author = {Vincenti, H. and Wheeler, J. and Monchoce, S. and Borot, A. and Malvache, A. and Lopez-Martens, R. and Quere, F.},
  title = {Attosecond lighthouses},
  journal = {2012 Conference on Lasers and Electro-Optics (CLEO)},
  year = {2012},
  pages = {IEEE Photonics Soc.},
  doi = {10.1364/QELS.2012.QTu3H.2}
}
"Attosecond lighthouses from plasma mirrors"
Wheeler JA, Borot A, Monchoce S, Vincenti H, Ricci A, Malvache A, Lopez-Martens R and Quere F, Nature Photonics., Vol. 6(12), pp. 828-832 - December, (2012).
Abstract: The nonlinear interaction of an intense femtosecond laser pulse with matter can lead to the emission of a train of sub-laser-cycle-attosecond-bursts of short-wavelength radiation1, 2. Much effort has been devoted to producing isolated attosecond pulses, as these are better suited to real-time imaging of fundamental electronic processes3, 4, 5, 6. Successful methods developed so far rely on confining the nonlinear interaction to a single sub-cycle event7, 8, 9. Here, we demonstrate for the first time a simpler and more universal approach to this problem10, applied to nonlinear laser-plasma interactions. By rotating the instantaneous wavefront direction of an intense few-cycle laser field11, 12 as it interacts with a solid-density plasma, we separate the nonlinearly generated attosecond pulse train into multiple beams of isolated attosecond pulses propagating in different and controlled directions away from the plasma surface. This unique method produces a manifold of isolated attosecond pulses, ideally synchronized for initiating and probing ultrafast electron motion in matter
BibTeX:
@article{Wheeler2012a,
  author = {Wheeler, Jonathan A. and Borot, Antonin and Monchoce, Sylvain and Vincenti, Henri and Ricci, Aurelien and Malvache, Arnaud and Lopez-Martens, Rodrigo and Quere, Fabien},
  title = {Attosecond lighthouses from plasma mirrors},
  journal = {Nature Photonics},
  year = {2012},
  volume = {6},
  number = {12},
  pages = {828--832},
  doi = {10.1038/NPHOTON.2012.284}
}
"Attosecond lighthouses from plasma mirrors"
Wheeler J, Borot A, Malvache A, Ricci A, Jullien A, Lopez-Martens R, Monchoce S, Vincenti H and Quere F, 2012 Conference on Lasers and Electro-Optics (CLEO). , pp. IEEE Photonics Soc. - (2012).
Abstract: We demonstrate for the first time experimentally a universal method - attosecond lighthouse effect - for producing temporally synchronized and spatially isolated attosecond light pulses, applied to a few-cycle laser-driven plasma mirror.
BibTeX:
@article{Wheeler2012b,
  author = {Wheeler, J. and Borot, A. and Malvache, A. and Ricci, A. and Jullien, A. and Lopez-Martens, R. and Monchoce, S. and Vincenti, H. and Quere, F.},
  title = {Attosecond lighthouses from plasma mirrors},
  journal = {2012 Conference on Lasers and Electro-Optics (CLEO)},
  year = {2012},
  pages = {IEEE Photonics Soc.},
  doi = {10.1364/QELS.2012.QTh5B.9}
}
2011
"High-harmonic generation from plasma mirrors at kilohertz repetition rate"
Borot A, Malvache A, Chen X, Douillet D, Iaquianiello G, Lefrou T, Audebert P, Geindre J-P, Mourou G, Quere F and Lopez-Martens R, Optics Letters., Vol. 36(8), pp. 1461-1463 - April, (2011).
Abstract: We report the first demonstration of high-harmonic generation from plasma mirrors at a 1kHz repetition rate. Harmonics up to nineteenth order are generated at peak intensities close to 10 18W/cm 2 by focusing 1mJ , 25fs laser pulses down to 1.7μm FWHM spot size without any prior wavefront correction onto a moving target. We minimize target surface motion with respect to the laser focus using online interferometry to ensure reproducible interaction conditions for every shot and record data at 1kHz with unprecedented statistics. This allows us to unambiguously identify coherent wake emission as the main generation mechanism.
BibTeX:
@article{Borot2011c,
  author = {Borot, Antonin and Malvache, Arnaud and Chen, Xiaowei and Douillet, Denis and Iaquianiello, Gregory and Lefrou, Thierry and Audebert, Patrick and Geindre, Jean-Paul and Mourou, Gerard and Quere, Fabien and Lopez-Martens, Rodrigo},
  title = {High-harmonic generation from plasma mirrors at kilohertz repetition rate},
  journal = {Optics Letters},
  year = {2011},
  volume = {36},
  number = {8},
  pages = {1461--1463},
  doi = {10.1364/OL.36.001461}
}
"Short pulse laser interaction with micro-structured targets: simulations of laser absorption and ion acceleration"
Klimo O, Psikal J, Limpouch J, Proska J, Novotny F, Ceccotti T, Floquet V and Kawata S, New Journal of Physics., Vol. 13, pp. 053028 - May, (2011).
The interaction of an ultrashort intense laser pulse with thin foil targets is accompanied by the acceleration of ions from the target surface. To make this ion source suitable for application, it is of particular importance to increase the efficiency of laser energy transformation into accelerated ions and the maximum ion energy. This can be achieved by using a thin foil target with a microscopic structure on the front, laser-irradiated surface. The influence of the microscopic structure on the target surface on the laser target interaction and subsequent ion acceleration is studied here using numerical simulations. The influence of the shape and size of the microstructure, the density profile and the laser pulse incidence angle is also studied. Based on the simulation results, we propose to construct the target for ion acceleration experiments by depositing a monolayer of polystyrene microspheres of a size similar to the laser wavelength on the front surface of a thin foil.
BibTeX:
@article{Klimo2011,
  author = {Klimo, O. and Psikal, J. and Limpouch, J. and Proska, J. and Novotny, F. and Ceccotti, T. and Floquet, V. and Kawata, S.},
  title = {Short pulse laser interaction with micro-structured targets: simulations of laser absorption and ion acceleration},
  journal = {New Journal of Physics},
  year = {2011},
  volume = {13},
  pages = {053028},
  doi = {10.1088/1367-2630/13/5/053028}
}
"Field ionization model implemented in Particle In Cell code and applied to laser-accelerated carbon ions"
Nuter R, Gremillet L, Lefebvre E, Levy A, Ceccotti T and Martin P, Physics of Plasmas., Vol. 18(3), pp. 033107 - March, (2011).
Abstract: A novel numerical modeling of field ionization in PIC (Particle In Cell) codes is presented. Based on the quasistatic approximation of the ADK (Ammosov Delone Krainov) theory and implemented through a Monte Carlo scheme, this model allows for multiple ionization processes. Two-dimensional PIC simulations are performed to analyze the cut-off energies of the laser-accelerated carbon ions measured on the UHI 10 Saclay facility. The influence of the target and the hydrocarbon pollutant composition on laser-accelerated carbon ion energies is demonstrated.
BibTeX:
@article{Nuter2011,
  author = {Nuter, R. and Gremillet, L. and Lefebvre, E. and Levy, A. and Ceccotti, T. and Martin, P.},
  title = {Field ionization model implemented in Particle In Cell code and applied to laser-accelerated carbon ions},
  journal = {Physics of Plasmas},
  year = {2011},
  volume = {18},
  number = {3},
  pages = {033107},
  doi = {10.1063/1.3559494}
}
  
"Modular EUV Source for the Next Generation Lithography"
Sublemontier O, Rosset-Kos M, Ceccotti T, Hergott J-F, Auguste T, Normand D, Schmidt M, Beaumont F, Farcage D, Cheymol G, Le Caro J-M, Cormont P, Mauchien P, Thro P-Y, Skrzypczak J, Muller S, Marquis E, Barthod B, Gaurand I, Davenet M and Bernard R, Journal of Laser Micro Nanoengineering., Vol. 6(2), pp. 113-118 - September, (2011).
Abstract: The present work, performed in the frame of the EXULITE project, was dedicated to the design and characterization of a laser-plasma-produced extreme ultraviolet (EUV) source prototype at 13.5 nm for the next generation lithography. It was conducted in cooperation with two laboratories from CEA, ALCATEL and THALES. One of our approach originalities was the laser scheme modularity. Six Nd:YAG laser beams were focused at the same time on a xenon filament jet to generate the EUV emitting plasma. Multiplexing has important industrial advantages and led to interesting source performances in terms of in-band power, stability and angular emission properties with the filament jet target. A maximum conversion efficiency (CE) value of 0.44% in 2$ sr and 2% band-width was measured, which corresponds to a maximum in band EUV mean power of 7.7 W at a repetition rate of 6 kHz. The EUV emission was found to be stable and isotropic in these conditions.
BibTeX:
@article{Sublemontier2011,
  author = {Sublemontier, Olivier and Rosset-Kos, Marylene and Ceccotti, Tiberio and Hergott, Jean-Francois and Auguste, Thierry and Normand, Didier and Schmidt, Martin and Beaumont, Francois and Farcage, Daniel and Cheymol, Guy and Le Caro, Jean-Marc and Cormont, Philippe and Mauchien, Patrick and Thro, Pierre-Yves and Skrzypczak, Jacky and Muller, Sophie and Marquis, Emanuel and Barthod, Benoit and Gaurand, Isabelle and Davenet, Magali and Bernard, Roland},
  title = {Modular EUV Source for the Next Generation Lithography},
  journal = {Journal of Laser Micro Nanoengineering},
  year = {2011},
  volume = {6},
  number = {2},
  pages = {113--118},
  doi = {10.2961/jlmn.2011.02.0004}
}
2010
"Towards Laser-Driven, Quasi-Monochromatic Ion Bunches via Ultrathin Targets Nano-Structuring?"
Betti S, Giulietti A, Giulietti D, Gizzi LA, Vaselli M, Cecchetti CA, Gamucci A, Koester P, Labate L, Pathak N, Levato T, Andreev AA, Ceccotti T, Martin P and Monot P, 2nd International Conference On Ultra-intense Laser Interaction Science. Vol. 1209, pp. Lab Nazl Frascati, Ist Nazl Fisca Nucl; Ist Processi Chimico FisiciEOLEOLConsiglio Nazl Ric; Inst IRAMIS Commissariat Energie Atomique; AmplitudeEOLEOLTechnol; CVI Melles Griot; Thales Laser; Unibiomedics - (2010).
Abstract: The conditions for achieving the laser acceleration of quasi-monochromatic ion bunches with present-day, fs laser systems are theoretically discussed. The study suggests the possibility of achieving quasi-monochromaticity via irradiation of double-layer, nano-structured foils and the conjecture is numerically confirmed by means of two dimensional, Particle-In-Cell (PIC) simulations. A feasible setup in order to experimentally validate this approach is thus proposed.
BibTeX:
@article{Betti2010,
  author = {Betti, S. and Giulietti, A. and Giulietti, D. and Gizzi, L. A. and Vaselli, M. and Cecchetti, C. A. and Gamucci, A. and Koester, P. and Labate, L. and Pathak, N. and Levato, T. and Andreev, A. A. and Ceccotti, T. and Martin, P. and Monot, P.},
  title = {Towards Laser-Driven, Quasi-Monochromatic Ion Bunches via Ultrathin Targets Nano-Structuring?},
  journal = {2nd International Conference On Ultra-intense Laser Interaction Science},
  year = {2010},
  volume = {1209},
  pages = {Lab Nazl Frascati, Ist Nazl Fisca Nucl; Ist Processi Chimico FisiciEOLEOLConsiglio Nazl Ric; Inst IRAMIS Commissariat Energie Atomique; AmplitudeEOLEOLTechnol; CVI Melles Griot; Thales Laser; Unibiomedics},
  doi = {10.1063/1.3326308}
}
"Results of a laser-driven electron acceleration experiment and perspectives of application for nuclear studies"
Gamucci A, Bourgeois N, Ceccotti T, Davoine X, Dobosz Dufrénoy S, D'Oliveira P, Galimberti M, Galy J, Giulietti A, Giulietti D, Gizzi LA, Hamilton DJ, Labate L, Lefebvre E, Marques JR, Martin P, Monot P, Popescu H, Reau F, Sarri G and Tomassini P, Radiation Effects and Defects In Solids. Vol. 165(6-10), pp. Messina Univ; Inst Nazl Fis Nucl; Salento Univ Lecce; Bonino Pulejo FdnEOLEOLMessina - (2010).
Abstract: High-energy electrons can be produced in interactions of intense, ultra-short laser pulses with plasmas. Experiments conducted in the regime of moderate laser power (a few terawatts [TW]) are attracting increasing attention for their possibility of optimizing the acceleration process. Here we report the successful production of several-MeV electron bunches in interactions of femtosecond laser pulses from a 10 TW tabletop laser with supersonic gas-jets. The laser-plasma interaction and the obtained electron bunches have been characterized in detail, and conditions for stable and reproducible acceleration have been found. The accelerated electron bunches have been characterized by means of the measurement of the induced photo-activation of a gold sample via bremsstrahlung-generation of photons with suitable energy. The obtained result opens up a wide range of possible applications of the compact electron source for the concerns of nuclear physics studies. Some of them are briefly considered in this paper.
BibTeX:
@article{Gamucci2010,
  author = {Gamucci, A. and Bourgeois, N. and Ceccotti, T. and Davoine, X. and Dobosz Dufrénoy, S. and D'Oliveira, P. and Galimberti, M. and Galy, J. and Giulietti, A. and Giulietti, D. and Gizzi, L. A. and Hamilton, D. J. and Labate, L. and Lefebvre, E. and Marques, J. R. and Martin, P. and Monot, P. and Popescu, H. and Reau, F. and Sarri, G. and Tomassini, P.},
  title = {Results of a laser-driven electron acceleration experiment and perspectives of application for nuclear studies},
  journal = {Radiation Effects and Defects In Solids},
  year = {2010},
  volume = {165},
  number = {6-10},
  pages = {Messina Univ; Inst Nazl Fis Nucl; Salento Univ Lecce; Bonino Pulejo FdnEOLEOLMessina},
  doi = {10.1080/10420151003731983}
}
"Laser-IORT: a laser-driven source of relativistic electrons suitable for Intra-Operative Radiation Therapy of tumors"
Gamucci A, Bourgeois N, Ceccotti T, Davoine X, Dobosz Dufrénoy S, D'Oliveira P, Galimberti M, Galy J, Giulietti A, Giulietti D, Gizzi LA, Hamilton DJ, Labate L, Lefebvre E, Marques JR, Monot P, Popescu H, Reau F, Sarri G, Tomassini P and Martin P, 2nd International Conference On Ultra-intense Laser Interaction Science. Vol. 1209, pp. Lab Nazl Frascati, Ist Nazl Fisca Nucl; Ist Processi Chimico FisiciEOLEOLConsiglio Nazl Ric; Inst IRAMIS Commissariat Energie Atomique; AmplitudeEOLEOLTechnol; CVI Melles Griot; Thales Laser; Unibiomedics - (2010).
Abstract: In a recent experiment [1] a high efficiency regime of stable electron acceleration to kinetic energies ranging from 10 to 40 MeV has been achieved. The main parameters of the electron bunches are comparable with those of bunches provided by commercial Radio-Frequency based Linacs currently used in Hospitals for Intra-Operative Radiation Therapy (IORT). IORT is an emerging technique applied in operating theaters during the surgical treatment of tumors. Performances and structure of a potential laser-driven Hospital accelerator are compared in detail with the ones of several commercial devices. A number of possible advantages of the laser based technique are also discussed.
BibTeX:
@article{Gamucci2010a,
  author = {Gamucci, A. and Bourgeois, N. and Ceccotti, T. and Davoine, X. and Dobosz Dufrénoy, S. and D'Oliveira, P. and Galimberti, M. and Galy, J. and Giulietti, A. and Giulietti, D. and Gizzi, L. A. and Hamilton, D. J. and Labate, L. and Lefebvre, E. and Marques, J. R. and Monot, P. and Popescu, H. and Reau, F. and Sarri, G. and Tomassini, P. and Martin, Ph.},
  title = {Laser-IORT: a laser-driven source of relativistic electrons suitable for Intra-Operative Radiation Therapy of tumors},
  journal = {2nd International Conference On Ultra-intense Laser Interaction Science},
  year = {2010},
  volume = {1209},
  pages = {Lab Nazl Frascati, Ist Nazl Fisca Nucl; Ist Processi Chimico FisiciEOLEOLConsiglio Nazl Ric; Inst IRAMIS Commissariat Energie Atomique; AmplitudeEOLEOLTechnol; CVI Melles Griot; Thales Laser; Unibiomedics},
  doi = {10.1063/1.3326314}
}
"High-order harmonic and attosecond pulse generation on plasma mirrors: basic mechanisms"
Thaury C and Quere F, Journal of Physics B-atomic Molecular and Optical Physics., Vol. 43(21), pp. 213001 - November, (2010).
Abstract: When an intense femtosecond laser pulse hits an optically polished surface, it generates a dense plasma that itself acts as a mirror, known as the plasma mirror. As this mirror reflects the high-intensity laser field, its nonlinear temporal response can lead to a periodic temporal distortion of the reflected wave, associated with a train of attosecond light pulses, and, in the frequency domain, to the generation of high-order harmonics of the laser. This tutorial presents detailed theoretical and numerical analysis of the two dominant harmonic generation mechanisms identified so far, coherent wake emission and the relativistic oscillating mirror. Parametric studies of the emission efficiency are presented for these two regimes, and the phase properties of the corresponding harmonics are discussed. This theoretical study is complemented by a synthesis of recent experimental results, which establishes that these two mechanisms indeed dominate harmonic generation on plasma mirrors.
BibTeX:
@article{Thaury2010a,
  author = {Thaury, C. and Quere, F.},
  title = {High-order harmonic and attosecond pulse generation on plasma mirrors: basic mechanisms},
  journal = {Journal of Physics B-atomic Molecular and Optical Physics},
  year = {2010},
  volume = {43},
  number = {21},
  pages = {213001},
  doi = {10.1088/0953-4075/43/21/213001}
}
"Intrinsic phase of high order harmonics generated on plasma mirrors"
Thaury C, Quere F, George H, Geindre JP, Bonnaud G and Martin P, Light At Extreme Intensities: Opportunities and Technological Issues of the Extreme Light Infrastructure. Vol. 1228, pp. Int Consortium Extreme Light Infrastruct; Natl Inst Laser, Plasma \&EOLEOLRadiat Phys; Inst Plasmas \& Fusao Nucl; Natl Author Sci Res; EmbassyEOLEOLFrance Romania; Transilvania Univ Brasov - (2010).
Abstract: We study numerically and experimentally the intrinsic phase of Coherent Wake Emission harmonics. We first use 1D3V particle-in-cell simulations to identify the origin of the phase. Then we present experimental results showing that it can be controlled by tailoring the laser pulse, and measured precisely using an interferometric technique.
BibTeX:
@article{Thaury2010,
  author = {Thaury, C. and Quere, F. and George, H. and Geindre, J. -. P. and Bonnaud, G. and Martin, Ph.},
  title = {Intrinsic phase of high order harmonics generated on plasma mirrors},
  journal = {Light At Extreme Intensities: Opportunities and Technological Issues of the Extreme Light Infrastructure},
  year = {2010},
  volume = {1228},
  pages = {Int Consortium Extreme Light Infrastruct; Natl Inst Laser, Plasma &EOLEOLRadiat Phys; Inst Plasmas & Fusao Nucl; Natl Author Sci Res; EmbassyEOLEOLFrance Romania; Transilvania Univ Brasov},
  doi = {10.1063/1.3426078}
}
2009
"Proton Maximum Energy Cutoff Scaling Laws For Bulk Targets"
Passoni M, Bertagna L, Ceccotti T and Martin P, Laser-driven Relativistic Plasmas Applied To Science, Industry and Medicine. : 2nd International Symposium - Date:19–23 January 2009 - Location: Kyoto (Japan) - (2009).
Abstract: In this work we experimentally and theoretically report on the energy cutoff scaling law for proton generation from bulk targets over one decade of intensity ranging from 5?1018 to 5?1019 W/cm2 in the ultra-short pulse duration regime (25 fs). Assuming the same experimental conditions and that the physics does not change for higher intensities, we extrapolate that 100 MeV could be reached using 500 TW ultra-high-contrast-ultra short laser pulses.
BibTeX:
@article{Passoni2009,
  author = {Passoni, M. and Bertagna, L. and Ceccotti, T. and Martin, P.},
  title = {Proton Maximum Energy Cutoff Scaling Laws For Bulk Targets},
  journal = {Laser-driven Relativistic Plasmas Applied To Science, Industry and Medicine},
  year = {2009},
  doi = {10.1063/1.3204520}
}
"Ultrafast science: Attosecond plasma optics"
Quere F, Nature Physics., Vol. 5(2), pp. 93-94 - February, (2009).
Abstract: Using dense plasmas instead of atomic or molecular gases could enable the generation of attosecond light pulses with higher energy, shorter durations and more energetic photons.
BibTeX:
@article{Quere2009a,
  author = {Quere, Fabien},
  title = {Ultrafast science: Attosecond plasma optics},
  journal = {Nature Physics},
  year = {2009},
  volume = {5},
  number = {2},
  pages = {93--94},
  doi = {10.1038/nphys1191}
}
"Attosecond and femtosecond metrology for plasma mirrors"
Quere F, George H and Martin P, Harnessing Relativistic Plasma Waves As Novel Radiation Sources From Terahertz To X-rays and Beyond. Vol. 7359, pp. SPIE Europe - (2009).
Abstract: When an intense ultrashort laser pulse impinges on an initially-solid target, it creates a dense plasma at the surface, which reflects a large fraction of the incident light. At high enough intensities, high-order harmonics of the incident laser frequency, associated in the time domain to trains of attosecond pulses, are generated in the light beam specularly reflected by this "plasma mirror". The mechanisms leading to this generation are now relatively well-established, and the first experimental evidence for attosecond pulses generated on plasma mirrors has recently been reported. An accurate characterization of the temporal structure of the light reflected by plasma mirrors, down to the attosecond scale, however remains an experimental challenge. In this paper, we describe three different methods that could be used for such temporal measurements, from the femtosecond to the attosecond time scale. Two of them are interferometric techniques which only require measurements of photons, while the third one is a new configuration of a now well-established method, developed for attosecond pulses generated in gases, and based on photoelectron spectroscopy.
BibTeX:
@article{Quere2009,
  author = {Quere, F. and George, H. and Martin, Ph.},
  title = {Attosecond and femtosecond metrology for plasma mirrors},
  journal = {Harnessing Relativistic Plasma Waves As Novel Radiation Sources From Terahertz To X-rays and Beyond},
  year = {2009},
  volume = {7359},
  pages = {SPIE Europe},
  doi = {10.1117/12.822010}
}
"Internal frequency conversion extreme ultraviolet interferometer using mutual coherence properties of two high-order-harmonic sources"
Dobosz Dufrénoy S, Stabile H, Tortora A, Monot P, Reau F, Bougeard M, Merdji H, Carre B, Martin P, Joyeux D, Phalippou D, Delmotte F, Gautier J and Mercier R, Review of Scientific Instruments., Vol. 80(11), pp. 113102 - November, (2009).
Abstract: We report on an innovative two-dimensional imaging extreme ultraviolet (XUV) interferometer operating at 32 nm based on the mutual coherence of two laser high order harmonics (HOH) sources, separately generated in gas. We give the first evidence that the two mutually coherent HOH sources can be produced in two independent spatially separated gas jets, allowing for probing centimeter-sized objects. A magnification factor of 10 leads to a micron resolution associated with a subpicosecond temporal resolution. Single shot interferograms with a fringe visibility better than 30% are routinely produced. As a test of the XUV interferometer, we measure a maximum electronic density of 3x10(20) cm(-3) 1.1 ns after the creation of a plasma on aluminum target.
BibTeX:
@article{Dobosz2009a,
  author = {Dobosz Dufrénoy, S. and Stabile, H. and Tortora, A. and Monot, P. and Reau, F. and Bougeard, M. and Merdji, H. and Carre, B. and Martin, Ph. and Joyeux, D. and Phalippou, D. and Delmotte, F. and Gautier, J. and Mercier, R.},
  title = {Internal frequency conversion extreme ultraviolet interferometer using mutual coherence properties of two high-order-harmonic sources},
  journal = {Review of Scientific Instruments},
  year = {2009},
  volume = {80},
  number = {11},
  pages = {113102},
  doi = {10.1063/1.3257676}
}
"Mechanisms of forward laser harmonic emission from thin overdense plasmas"
George H, Quere F, Thaury C, Bonnaud G and Martin P, New Journal of Physics., Vol. 11, pp. 113028 - November, (2009).
Abstract: As a high-intensity laser pulse impinges a thin solid foil, high-order harmonics of the incident frequency can be observed at the rear (non-illuminated) side of this foil. Using numerical simulations, we show that these harmonics can be generated either at the front or at the rear side of the target. We analyze the mechanisms responsible for these two types of emission, and discuss their connection with those involved in the generation of harmonics detected on the front side. The combined measurements of spectra on both sides of the target constitute a powerful, but often nontrivial, probe of the ultrafast plasma dynamics.
BibTeX:
@article{George2009,
  author = {George, H. and Quere, F. and Thaury, C. and Bonnaud, G. and Martin, Ph},
  title = {Mechanisms of forward laser harmonic emission from thin overdense plasmas},
  journal = {New Journal of Physics},
  year = {2009},
  volume = {11},
  pages = {113028},
  doi = {10.1088/1367-2630/11/11/113028}
}
"Tracking propagation of ultrashort intense laser pulses in gases via probing of ionization"
Gizzi LA, Betti S, Galimberti M, Giulietti A, Giulietti D, Labate L, Levato T, Tomassini P, Monot P, Ceccotti T, D'Oliveira P and Martin P, Physical Review E., Vol. 79(5), pp. 056405 - May, (2009).
Abstract: We use optical interferometry to study the propagation of femtosecond laser pulses in gases. We show the measurements of propagation in a nitrogen gas jet and we compare the results with propagation in He under the same irradiation conditions. We find that in the case of nitrogen, the detailed temporal structure of the laser pulse can be tracked and visualized by measuring the phase and the resulting electron-density map. A dramatically different behavior occurs in He gas jets, where no details of the temporal structure of the laser pulse are visible. These observations are explained in terms of the ionization dynamics of nitrogen compared to helium. These circumstances make N2 gas sensitive to variations in the electric field and, therefore, allow the laser-pulse temporal and spatial structures to be visualized in detail.
BibTeX:
@article{Gizzi2009,
  author = {Gizzi, L. A. and Betti, S. and Galimberti, M. and Giulietti, A. and Giulietti, D. and Labate, L. and Levato, T. and Tomassini, P. and Monot, P. and Ceccotti, T. and De Oliveira, P. and Martin, Ph.},
  title = {Tracking propagation of ultrashort intense laser pulses in gases via probing of ionization},
  journal = {Physical Review E},
  year = {2009},
  volume = {79},
  number = {5},
  pages = {056405},
  doi = {10.1103/PhysRevE.79.056405}
}
"Ion acceleration in ultra-high contrast regime"
Levy A, Ceccotti T, Popescu H, Reau F, D'Oliveira P, Monot P, Martin P, Geindre JP and Lefebvre E , European Physical Journal-special Topics., Vol. 175, pp. 111-116 - August, (2009).
Abstract: In this work, we demonstrate that the contrast of high intensity laser pulses is a key issue for many problems dealing with high-field interaction with solid-density matter. As an example, we will discuss the interaction of an Ultra-High-Contrast (UHC), Ultra-Intense, 65 fs laser pulse with an overdense plasma through the proton acceleration from ultra-thin foils (from 0.08 μm to 105 μm). The symmetric feature of the ion beams emitted from both faces of the target will be demonstrated as well as the dominant role of the p component of the electric field rather than the ponderomotive force. Simulations performed with a 2D particle-in-cell code are in close agreement with all experimental data. UHC experiments prove to be a good as benchmarks for theories and models.
BibTeX:
@article{Levy2009,
  author = {Levy, A. and Ceccotti, T. and Popescu, H. and Reau, F. and D'Oliveira, P. and Monot, P. and Martin, Ph. and Geindre, J. P. and Lefebvre, E.},
  title = {Ion acceleration in ultra-high contrast regime},
  journal = {European Physical Journal-special Topics},
  year = {2009},
  volume = {175},
  pages = {111--116},
  doi = {10.1140/epjst/e2009-01126-3}
}
"Effect of a nanometer scale plasma on laser-accelerated ion beams"
Levy A, Nuter R, Ceccotti T, Combis P, Drouin M, Gremillet L, Monot P, Popescu H, Reau F, Lefebvre E and Martin P, New Journal of Physics., Vol. 11, pp. 093036 - September, (2009).
Abstract: Energies of laser-accelerated ions from thin foils in the so-called 'ultra-high-contrast' regime have been measured for various preformed plasma sizes on the non-irradiated foil surface. Whereas energies of protons accelerated in the laser counter-propagating direction remain almost constant for plasma scale length up to 300?nm, we found that plasmas as short as a few tens of nanometers reduce the maximum energy of ions accelerated in the laser direction. These experimental measurements are numerically confirmed with two-dimensional particle-in-cell simulations coupled to hydrodynamic calculation. Moreover, our experimental results, supported by simulations, provide evidence for the occurrence of ion wave breaking, and demonstrate its ability to mitigate the ion energy reduction due to the plasma gradient. This wave breaking is observed and characterized for both proton and carbon ion components.
BibTeX:
@article{Levy2009a,
  author = {Levy, A. and Nuter, R. and Ceccotti, T. and Combis, P. and Drouin, M. and Gremillet, L. and Monot, P. and Popescu, H. and Reau, F. and Lefebvre, E. and Martin, P.},
  title = {Effect of a nanometer scale plasma on laser-accelerated ion beams},
  journal = {New Journal of Physics},
  year = {2009},
  volume = {11},
  pages = {093036},
  doi = {10.1088/1367-2630/11/9/093036}
}
"Enhanced ion acceleration with extremely thin foils"
Loch R.A, Levy A, Ceccotti T, Quere F, Thaury C, George H, Bijkerk F, Boller K.J and Martin P, European Physical Journal-special Topics., Vol. 175, pp. 133-138 - August, (2009).
Abstract: Enhanced backward-acceleration of ions is experimentally observed when ultra-short, high-intensity and ultra-high-contrast laser pulses interact with thin foils having thicknesses in the order of the penetration depth of the laser light. Below the experimentally observed optimum foil thickness for the maximum ion energy versus thickness, there arises a second peak. 1D simulations on foils with an initial plasma density gradient show a similar trend as the experiment. It appears that in this regime of extremely thin foils it is important to take into account the limited expansion of the plasma that is formed by ultra-high-contrast pulses.
BibTeX:
@article{Loch2009a,
  author = {Loch, R. A. and Levy, A. and Ceccotti, T. and Quere, F. and Thaury, C. and George, H. and Bijkerk, F. and Boller, K. -. J. and Martin, Ph.},
  title = {Enhanced ion acceleration with extremely thin foils},
  journal = {European Physical Journal-special Topics},
  year = {2009},
  volume = {175},
  pages = {133--138},
  doi = {10.1140/epjst/e2009-01130-7}
}
i>"High-Order Harmonic And Fast Ion Generation In High Intensity Laser-Solid Interactions"
Loch R.A, Martin P, Ceccotti T, Monot P, Quere F, George H, Bougeard M, Reau F, D'Oliveira P and Boller K.J, Laser-driven Relativistic Plasmas Applied To Science, Industry and Medicine: 2nd International Symposium - Date: 19–23 January 2009 - Location Kyoto (Japan) - (2009).
Abstract: Experiments on high-order harmonic generation and ion acceleration are performed with the new installed 100 TW, 25 fs laser in Saclay (UHI100). These experiments require a very high laser pulse contrast. The suppression of prepulse energy is achieved by using a double plasma mirror, which results in a contrast of 1013.
BibTeX:
@article{Loch2009,
  author = {Loch, R. A. and Martin, Ph. and Ceccotti, T. and Monot, P. and Quere, F. and George, H. and Bougeard, M. and Reau, F. and D'Oliveira, P. and Boller, K. -. J.},
  title = {High-Order Harmonic And Fast Ion Generation In High Intensity Laser-Solid Interactions},
  journal = {Laser-driven Relativistic Plasmas Applied To Science, Industry and Medicine},
  year = {2009},
  volume = {1153},
  pages = {Japan Atom Energy Agcy, Photo-Med Valley & Photo-Med Res Ctr; Inst JapanEOLEOLAtom Energy Agcy, Adv Photon Res Ctr & Kansai Photon Sci; Minist Educ,EOLEOLCulture, Sports, Sci & Technol Japan; Japan Soc Promot Sci Core-to-CoreEOLEOLProgram; Int Collaborat High Dens Energy Sci; Japan Soc Promot Sci Res;EOLEOLOsaka Univ, Inst Laser Engn; Int Sci & Technol Ctr; Consortium PhotonEOLEOLSci & Technol},
  doi = {10.1140/epjst/e2009-01115-6}
}
"High-order harmonic generation from plasma mirrors"
Thaury C, Quere F, George H, Geindre JP, Monot P and Martin P, European Physical Journal-special Topics., Vol. 175, pp. 43-48 - August, (2009).
Abstract: We discuss the two mechanisms involved in high-order harmonic generation from plasma mirrors, and show that they can be clearly identified experimentally. The very different phase properties of the corresponding harmonics lead to light beams with different divergences. This can be exploited to select a particular type of harmonic by spatial filtering in the far-field.
BibTeX:
@article{Thaury2009,
  author = {Thaury, C. and Quere, F. and George, H. and Geindre, J. P. and Monot, P. and Martin, Ph.},
  title = {High-order harmonic generation from plasma mirrors},
  journal = {European Physical Journal-special Topics},
  year = {2009},
  volume = {175},
  pages = {43--48},
  doi = {10.1140/epjst/e2009-01115-6}
}
"Probing the dynamics of plasma mirrors on the attosecond time scale"
Thaury C, Quere F, George H, Loch RA, Geindre JP, Monot P and Martin P, Ultrafast Phenomena Xvi. Vol. 92, pp. 93-95 (2009).
Abstract: We demonstrate that the generation of high-order harmonics (HHG) of a laser on plasma mirrors preserves the coherence of the laser. We then exploit this coherence to study the dynamics of the plasma electrons.
BibTeX:
@article{Thaury2009a,
  author = {Thaury, C. and Quere, F. and George, H. and Loch, R. A. and Geindre, J. -. P. and Monot, P. and Martin, Ph.},
  title = {Probing the dynamics of plasma mirrors on the attosecond time scale},
  journal = {Ultrafast Phenomena Xvi},
  year = {2009},
  volume = {92},
  pages = {93--95},
  doi = {10.1007/978-3-540-95946-5_31}
}
2008
"Fast-ion energy-flux enhancement from ultrathin foils irradiated by intense and high-contrast short laser pulses."
Andreev A, Levy A, Ceccotti T, Thaury C, Platonov K, Loch RA and Martin P, Physical review letters., Vol. 101(15), pp. 155002-155002 - October, (2008).
Abstract: Recent significant improvements of the contrast ratio of chirped pulse amplified pulses allows us to extend the applicability domain of laser accelerated protons to very thin targets. In this framework, we propose an analytical model particularly suitable to reproducing ion laser acceleration experiments using high intensity and ultrahigh contrast pulses. The model is based on a self-consistent solution of the Poisson equation using an adiabatic approximation for laser generated fast electrons which allows one to find the target thickness maximizing the maximum proton (and ion) energies and population as a function of the laser parameters. Model furnished values show a good agreement with experimental data and 2D particle-in-cell simulation results.
BibTeX:
@article{Andreev2008,
  author = {Andreev, A. and Levy, A. and Ceccotti, T. and Thaury, C. and Platonov, K. and Loch, R. A. and Martin, Ph},
  title = {Fast-ion energy-flux enhancement from ultrathin foils irradiated by intense and high-contrast short laser pulses.},
  journal = {Physical review letters},
  year = {2008},
  volume = {101},
  number = {15},
  pages = {155002--155002},
  doi = {10.1103/PhysRevLett.101.155002}
}
"TNSA in the ultra-high contrast regime"
Ceccotti T, Levy A, Reau F, Popescu H, Monot P, Lefebvre E and Martin P, Plasma Physics and Controlled Fusion., December, 2008. Vol. 50(12), pp. European Phys Soc - (2008).
Abstract: We present some of the results obtained when an ultra-high-intensity (~5 * 1018W?cm-2), ultra-high contrast (>1010) laser pulse interacts with thins foils. Under such conditions, protons accelerated by the target normal sheat acceleration mechanism are observed from both sides of the target and show quasi-symmetric features which have been corroborated by extensive 1D and 2D particle-in-cell simulations. Moreover, we show that due to the very steep gradient of the laser-irradiated surface, the Brunel effect is the main laser energy coupling mechanism.
BibTeX:
@article{Ceccotti2008,
  author = {Ceccotti, T. and Levy, A. and Reau, F. and Popescu, H. and Monot, P. and Lefebvre, E. and Martin, Ph},
  title = {TNSA in the ultra-high contrast regime},
  journal = {Plasma Physics and Controlled Fusion},
  year = {2008},
  volume = {50},
  number = {12},
  pages = {European Phys Soc},
  doi = {10.1088/0741-3335/50/12/124006}
}
"Non-adiabatic cluster expansion after ultrashort laser interaction"
Faenov AY, Magunov AI, Pikuz TA, Skobelev IY, Giulietti D, Betti S, Galimberti M, Gamucci A, Giulietti A, Gizzi LA, Labate L, Levato T, Tomassini P, Marques JR, Bourgeois N, Dobosz Dufrénoy S, Ceccotti T, Monot P, Reau F, Popescu H, D'Oliveira P, Martin P, Fukuda Y, Boldarev AS, Gasilov SV and Gasilov VA, Laser and Particle Beams., Vol. 26(1), pp. 69-81 - March, (2008).
Abstract: We used X-ray spectroscopy as a diagnostic tool for investigating the properties of laser-cluster interactions at the stage in which non-adiabatic cluster expansion takes place and a quasi-homogeneous plasma is produced. The experiment was carried out with a 10 TW, 65 fs Ti:Sa laser focused on CO 2 cluster jets. The effect of different laser-pulse contrast ratios and cluster concentrations was investigated. The X-ray emission associated to the Rydberg transitions allowed us to retrieve, through the density and temperature of the emitting plasma, the time after the beginning of the interaction at which the emission occurred. The comparison of this value with the estimated time for the "homogeneous" plasma formation shows that the degree of adiabaticity depends on both the cluster concentration and the pulse contrast. Interferometric measurements support the X-ray data concerning the plasma electron density.
BibTeX:
@article{Faenov2008,
  author = {Faenov, A. Ya. and Magunov, A. I. and Pikuz, T. A. and Skobelev, I. Yu. and Giulietti, D. and Betti, S. and Galimberti, M. and Gamucci, A. and Giulietti, A. and Gizzi, L. A. and Labate, L. and Levato, T. and Tomassini, P. and Marques, J. R. and Bourgeois, N. and Dobosz Dufrénoy, S and Ceccotti, T. and Monot, P. and Reau, F. and Popescu, H. and D'Oliveira, P. and Martin, Ph. and Fukuda, Y. and Boldarev, A. S. and Gasilov, S. V. and Gasilov, V. A.},
  title = {Non-adiabatic cluster expansion after ultrashort laser interaction},
  journal = {Laser and Particle Beams},
  year = {2008},
  volume = {26},
  number = {1},
  pages = {69--81},
  doi = {10.1017/S0263034608000104}
}
"Advanced diagnostics applied to a laser-driven electron-acceleration experiment"
Gamucci A, Bourgeois N, Ceccotti T, Dobosz Dufrénoy S, D'Oliveira P, Galimberti M, Galy J, Giulietti A, Giulietti D, Gizzi LA, Hamilton DJ, Labate L, Marques J-R, Monot P, Popescu H, Reau F, Sarri G, Tomassini P and Martin P, Ieee Transactions On Plasma Science., Vol. 36(4), pp. 1699-1706 - August, (2008).
Abstract: In this paper, the interaction of 10-TW laser pulses, focused at moderately relativistic intensity, with a supersonic helium gas-jet has been investigated by varying gas density and jet nozzle. We have successfully tested several advanced diagnostic devices to characterize the plasma and the accelerated electron bunches. Plasma densities have been measured by means of a femtosecond high-resolution interferometer, while the electron beams were analyzed with a stack of radiochromic films, a beam-profile monitor, a magnetic spectrometer, and a nuclear activation setup based on gamma-ray generation via electron bremsstrahlung. We present the results as well as the basic features and relevant details of such diagnostics whose performances can fit a large class of experiments.
BibTeX:
@article{Gamucci2008,
  author = {Gamucci, Andrea and Bourgeois, Nicolas and Ceccotti, Tiberio and Dobosz Dufrénoy, Sandrine and D'Oliveira, Pascal and Galimberti, Marco and Galy, Jean and Giulietti, Antonio and Giulietti, Danilo and Gizzi, Leomda A. and Hamilton, David J. and Labate, Luca and Marques, Jean-Raphael and Monot, Pascal and Popescu, Horia and Reau, Fabrice and Sarri, Gianluca and Tomassini, Paolo and Martin, Philippe},
  title = {Advanced diagnostics applied to a laser-driven electron-acceleration experiment},
  journal = {Ieee Transactions On Plasma Science},
  year = {2008},
  volume = {36},
  number = {4},
  pages = {1699--1706},
  doi = {10.1109/TPS.2008.2000898}
}
"Intense gamma-ray source in the giant-dipole-resonance range driven by 10-TW laser pulses."
Giulietti A, Bourgeois N, Ceccotti T, Davoine X, Dobosz Dufrénoy S, D'Oliveira P, Galimberti M, Galy J, Gamucci A, Giulietti D, Gizzi LA, Hamilton DJ, Lefebvre E, Labate L, Marques JR, Monot P, Popescu H, Reau F, Sarri G, Tomassini P and Martin P, Physical review letters., Vol. 101(10), pp. 105002-105002 - September, (2008).
Abstract: A gamma-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse.
BibTeX:
@article{Giulietti2008,
  author = {Giulietti, A. and Bourgeois, N. and Ceccotti, T. and Davoine, X. and Dobosz Dufrénoy, S. and D'Oliveira, P. and Galimberti, M. and Galy, J. and Gamucci, A. and Giulietti, D. and Gizzi, L. A. and Hamilton, D. J. and Lefebvre, E. and Labate, L. and Marques, J. R. and Monot, P. and Popescu, H. and Reau, F. and Sarri, G. and Tomassini, P. and Martin, P.},
  title = {Intense gamma-ray source in the giant-dipole-resonance range driven by 10-TW laser pulses.},
  journal = {Physical review letters},
  year = {2008},
  volume = {101},
  number = {10},
  pages = {105002--105002},
  doi = {10.1103/PhysRevLett.101.105002}
}
"Proton acceleration with high-intensity laser pulses in ultrahigh contrast regime"
Levy A, Ceccotti T, Popescu H, Reau F, D'Oliveira P, Monot P, Martin P, Geindre J-P and Lefebvre E, Ieee Transactions On Plasma Science., Vol. 36(4), pp. 1808-1811 - August, (2008).
Abstract: We investigate the interaction of a high-intensity (~5.1018 W/cm2) and short (~65 fs) laser pulse with thin foils (from 0.08 to 105 μm) in a regime of ultrahigh contrast (> 1010). This paper shows that for thicknesses less than about 10 μm, proton acceleration from both sides of the target presents quite symmetric features. Proton bunches emitted from each side show similar maximum energies and spatial characteristics. Moreover, we show that for ultrahigh-contrast pulses, the efficient acceleration mechanism is related to the Brunel effect and not to the ponderomotive force. Simulations performed with a 2-D particle-in-cell code are in close agreement with all experimental data.
BibTeX:
@article{Levy2008,
  author = {Levy, Anna and Ceccotti, Tiberio and Popescu, Horia and Reau, Fabrice and D'Oliveira, Pascal and Monot, Pascal and Martin, Philippe and Geindre, Jean-Paul and Lefebvre, Erik},
  title = {Proton acceleration with high-intensity laser pulses in ultrahigh contrast regime},
  journal = {Ieee Transactions On Plasma Science},
  year = {2008},
  volume = {36},
  number = {4},
  pages = {1808--1811},
  doi = {10.1109/TPS.2008.2001188}
}
"Phase properties of laser high-order harmonics generated on plasma mirrors."
Quere F, Thaury C, Geindre JP, Bonnaud G, Monot P and Martin P, Physical review letters., Vol. 100(9), pp. 095004-095004 - March, (2008).
Abstract: As a high-intensity laser-pulse reflects on a plasma mirror, high-order harmonics of the incident frequency can be generated in the reflected beam. We present a numerical study of the phase properties of these individual harmonics, and demonstrate experimentally that they can be coherently controlled through the phase of the driving laser field. The harmonic intrinsic phase, resulting from the generation process, is directly related to the coherent sub-laser-cycle dynamics of plasma electrons, and thus constitutes a new experimental probe of these dynamics.
BibTeX:
@article{Quere2008c,
  author = {Quere, F. and Thaury, C. and Geindre, J. -. P. and Bonnaud, G. and Monot, P. and Martin, Ph},
  title = {Phase properties of laser high-order harmonics generated on plasma mirrors.},
  journal = {Physical review letters},
  year = {2008},
  volume = {100},
  number = {9},
  pages = {095004--095004},
  doi = {10.1103/PhysRevLett.100.095004}
}
"Comment on "transition to the relativistic regime in high order harmonic generation"."
Quere F, Thaury C, Geindre JP and Martin P, Physical review letters., Vol. 100(8), pp. 089402-089401 - February, (2008).
Abstract: A Comment on the Letter by Alexander Tarasevitch et al.,
BibTeX:
@article{Quere2008h,
  author = {Quere, F. and Thaury, C. and Geindre, J. -. P. and Martin, Ph},
  title = {Comment on "transition to the relativistic regime in high order harmonic generation".},
  journal = {Physical review letters},
  year = {2008},
  volume = {100},
  number = {8},
  pages = {089402--089401;},
  doi = {10.1103/PhysRevLett.100.089401}
}
"Basic mechanisms of laser high-order harmonic generation from plasma mirrors"
Quere F, Thaury C, George H, Geindre JP, Lefebvre E, Bonnaud G, Hueller S, Monot P and Martin P, Journal of Modern Optics. Vol. 55(16), pp. 2711-2721 - (2008).
Abstract: We discuss the two mechanisms involved in high-order harmonic generation from plasma mirrors, which can be clearly identified in numerical simulations: the coherent wake emission (CWE) and the relativistic oscillating mirror (ROM) processes. Using high-contrast multi-TeraWatt ultrashort laser pulses, harmonics originating from these two processes can also be distinguished experimentally.
BibTeX:
@article{Quere2008b,
  author = {Quere, F. and Thaury, C. and George, H. and Geindre, J. P. and Lefebvre, E. and Bonnaud, G. and Hueller, S. and Monot, P. and Martin, Ph.},
  title = {Basic mechanisms of laser high-order harmonic generation from plasma mirrors},
  journal = {Journal of Modern Optics},
  year = {2008},
  volume = {55},
  number = {16},
  pages = {2711--2721},
  doi = {10.1080/09500340802187381}
}
"High-order harmonic generation using plasma mirrors"
Quere F, Thaury C, George H, Geindre JP, Lefebvre E, Bonnaud G, Monot P and Martin P, Plasma Physics and Controlled Fusion., Vol. 50(12), pp. European Phys Soc - December, (2008).
Abstract: We discuss the two mechanisms involved in high-order harmonic generation from plasma mirrors, which can be clearly identified in numerical simulations: the coherent wake emission (CWE) and the relativistic oscillating mirror (ROM) processes. Using high-contrast multi-terawatt ultrashort laser pulses, harmonics originating from these two processes can also be distinguished experimentally.
BibTeX:
@article{Quere2008e,
  author = {Quere, F. and Thaury, C. and George, H. and Geindre, J. P. and Lefebvre, E. and Bonnaud, G. and Monot, P. and Martin, Ph},
  title = {High-order harmonic generation using plasma mirrors},
  journal = {Plasma Physics and Controlled Fusion},
  year = {2008},
  volume = {50},
  number = {12},
  pages = {European Phys Soc},
  doi = {10.1088/0741-3335/50/12/124007}
}
"High-order harmonic generation in high intensity laser-solid interactions"
Quere F, Thaury C, George H, Geindre JP, Levy A, Ceccotti T, Monot P, Marjoribanks R, Audebert P and Martin P, 2008 Quantum Electronics and Laser Science Conference (QELS)., pp. 2 pp.-2 - January, (2008).
Abstract: We will discuss the two mechanisms involved in high-order harmonic generation from plasma mirrors, and show that they can be clearly identified experimentally. The phase and coherence properties of these harmonics will be analyzed.
BibTeX:
@article{Quere2008a,
  author = {Quere, F. and Thaury, C. and George, H. and Geindre, J. P. and Levy, A. and Ceccotti, T. and Monot, P. and Marjoribanks, R. and Audebert, P. and Martin, P.},
  title = {High-order harmonic generation in high intensity laser-solid interactions},
  journal = {2008 Quantum Electronics and Laser Science Conference (QELS)},
  year = {2008},
  pages = {2 pp.--2},
  doi = {10.1109/QELS.2008.4552898}
}
"Coherent dynamics of plasma mirrors"
Thaury C, George H, Quere F, Loch R, Geindre JP, Monot P and Martin P, Nature Physics., Vol. 4(8), pp. 631-634 - August, (2008).
Abstract: Coherent ultrashort X-ray pulses provide new ways to probe matter and its ultrafast dynamics1, 2, 3. One of the promising paths to generate these pulses consists of using a nonlinear interaction with a system to strongly and periodically distort the waveform of intense laser fields, and thus produce high-order harmonics. Such distortions have so far been induced by using the nonlinear polarizability of atoms, leading to the production of attosecond light bursts4, short enough to study the dynamics of electrons in matter3. Shorter and more intense attosecond pulses, together with higher harmonic orders, are expected5, 6 by reflecting ultraintense laser pulses on a plasma mirror-a dense (1023 electrons cm-3) plasma with a steep interface. However, short-wavelength-light sources produced by such plasmas are known to generally be incoherent7. In contrast, we demonstrate that like in usual low-intensity reflection, the coherence of the light wave is preserved during harmonic generation on plasma mirrors. We then exploit this coherence for interferometric measurements and thus carry out a first study of the laser-driven coherent dynamics of the plasma electrons.
BibTeX:
@article{Thaury2008,
  author = {Thaury, C. and George, H. and Quere, F. and Loch, R. and Geindre, J. -. P. and Monot, P. and Martin, Ph.},
  title = {Coherent dynamics of plasma mirrors},
  journal = {Nature Physics},
  year = {2008},
  volume = {4},
  number = {8},
  pages = {631--634},
  doi = {10.1038/nphys986}
}
"Radiothérapie miniature"
Michaut C, La Recherche - technologie - 01/11/2008 par Cécile Michaut dans mensuel n°424 à la page 26 - (2008).
Abstract: Le domaine médical a lui aussi ses accélérateurs de particules : il s'agit d'accélérateurs d'électrons, utilisés dans le traitement de certains cancers par radiothérapie. Très encombrants, ces derniers mesurent près de deux mètres de haut. Des chercheurs français et italiens tentent donc de les remplacer par un système à base de laser, plus petit et d'utilisation plus simple [1] .

La radiothérapie est une méthode qui permet d'éviter les récidives d'une tumeur après son ablation. Elle consiste à irradier la zone opérée, à l'aide d'électrons énergétiques qui détruisent les cellules cancéreuses restantes. Ce geste se déroule pendant l'opération, d'oů son nom de radiothérapie intra-opératoire ou IORT. Mais il nécessite l'installation d'un accélérateur d'électrons au sein même des blocs opératoires, ce qui, compte tenu des contraintes d'utilisation et d'encombrement, en limite la diffusion. Or, depuis quelques années, on sait accélérer des électrons par un autre moyen : les lasers. Le principe : des impulsions laser très brèves et très intenses sont envoyées sur un jet de gaz, ici du xénon, et éjectent une partie des électrons, formant un plasma. L'oscillation de ce plasma accélère les électrons à des vitesses proches de celle de la lumière [2, 3] .

Antonio Giulietti et ses collaborateurs, du Commissariat à l'énergie atomique CEA à Saclay, dans l'Essonne, et du Conseil italien de la recherche, à Pise, viennent de montrer que cette technique pourrait s'appliquer à la production d'électrons à usage médical. << Jusqu'à présent, les recherches étaient en quête de record : elles visaient à obtenir les électrons les plus énergétiques possibles, au détriment de leur nombre, commente Philippe Martin, l'un des auteurs de ce travail, du CEA de Saclay. Mais pour les applications médicales en IORT, des électrons moyennement énergétiques, de 10 à 20 mégaélectronvolts, suffisent. à ces énergies, il est plus facile d'en produire beaucoup, environ 1010 électrons par joule. C'est ce que nous avons fait, avec un laser commercial qui tient sur une table. » L'autre difficulté est de produire des électrons de manière reproductible, notamment en énergie. << C'est surtout en jouant sur la densité du gaz et la position du foyer du laser dans le jet de gaz que l'on atteint cette stabilité », indique Philippe Martin.

Ce dispositif n'est pas encore testé médicalement. En cas de succès, il permettrait, outre les économies espérées sur la taille et le coűt des installations, de soigner plusieurs personnes en parallèle, puisque le faisceau laser peut être transporté en même temps dans plusieurs salles. Et comme le laser est situé hors de la salle d'opération, la maintenance est assurée sans nuire à la stérilité des salles.

BibTeX:
@article{Michaut2008,
  author = {Michaut, Cécile},
  title = {Radiothérapie miniature},
  journal = {La Recherche - technologie - 01/11/2008 par Cécile Michaut dans mensuel n°424 à la page 26},
  year = {2008},
  url = {http://www.larecherche.fr/actualite/technologie/radiotherapie-miniature-01-11-2008-85830}
}
List created by JabRef on 23/05/2013.


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