PhD subjects

5 sujets IRAMIS//LIDYL

Dernière mise à jour :


• Plasma physics and laser-matter interactions

• Radiation-matter interactions

 

Implementation of a novel injector concept to boost the accelerated charge in laser-driven electron accelerators to enable their use for scientific and technological applications

SL-DRF-24-0352

Research field : Plasma physics and laser-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Physique à Haute Intensité (PHI)

Saclay

Contact :

Luca Fedeli

Henri VINCENTI

Starting date : 01-10-2024

Contact :

Luca Fedeli
CEA - DRF/IRAMIS/LIDyL/PHI

+33 1 69 08 19 59

Thesis supervisor :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Personal web page : https://iramis.cea.fr/LIDYL/Phocea/Pisp/index.php?nom=henri.vincenti

Laboratory link : https://iramis.cea.fr/LIDYL/PHI/

More : https://www.olcf.ornl.gov/2022/10/27/warpx-named-gordon-bell-prize-finalist/

Ultra-short, high-energy (up to few GeVs) electron beams can be accelerated over just a few centimeters by making an ultra-intense laser interact with a gas-jet, with a technique called “Laser Wakefield Acceleration” (LWFA). Thanks to their small size and the ultra-short duration of the accelerated electron beams, these devices are potentially interesting for a variety of scientific and technological applications. However, LWFA accelerators do not usually provide enough charge for most of the envisaged applications, in particular if a high beam quality and a high electron energy are also required. The goal of this thesis is to implement a novel LWFA injector concept in several state-of-the-art laser facilities, in France and abroad. This injector concept, recently conceived in our group, consists in a solid target coupled with a gas-jet, and should be able to accelerate a substantially higher amount of charge with respect to conventional strategies, while preserving at the same time the quality of the beam. The proposed activity is mainly experimental, but with the possibility to be involved in the large-scale numerical simulation activities that are needed to design an experiment and to interpret its results. The PhD student will have the opportunity to be part of a dynamic team with strong national and international collaborations. They will also acquire the necessary skills to participate in laser-plasma interaction experiments in international facilities. Finally, they’ll have the possibility to be involved in the numerical activities of the group, carried out on the most powerful supercomputers in the world with a state-of-the-art Particle-In-Cell code (WarpX, Gordon Bell prize in 2022).
Large-scale numerical modeling and optimization of a novel injector for laser-driven electron accelerators to enable their use for scientific and technological applications

SL-DRF-24-0353

Research field : Plasma physics and laser-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Physique à Haute Intensité (PHI)

Saclay

Contact :

Luca Fedeli

Henri VINCENTI

Starting date : 01-10-2024

Contact :

Luca Fedeli
CEA - DRF/IRAMIS/LIDyL/PHI

+33 1 69 08 19 59

Thesis supervisor :

Henri VINCENTI
CEA - DRF/IRAMIS/LIDyL/PHI

0169080376

Personal web page : https://iramis.cea.fr/LIDYL/Phocea/Pisp/index.php?nom=henri.vincenti

Laboratory link : https://iramis.cea.fr/LIDYL/PHI/

More : https://www.olcf.ornl.gov/2022/10/27/warpx-named-gordon-bell-prize-finalist/

Ultra-short, high-energy (up to few GeVs) electron beams can be accelerated over just a few centimeters by making an ultra-intense laser interact with a gas-jet, with a technique called “Laser Wakefield Acceleration” (LWFA). Thanks to their small size and the ultra-short duration of the accelerated electron beams, these devices are potentially interesting for a variety of scientific and technological applications. However, LWFA accelerators do not usually provide enough charge for most of the envisaged applications, in particular if a high beam quality and a high electron energy are also required.

The first goal of this thesis is to understand the basic physics of a novel LWFA injector concept recently conceived in our group. This injector consists of a solid target coupled with a gas-jet, and should be able to accelerate a substantially higher amount of charge with respect to conventional strategies, while preserving at the same time the quality of the beam. Large scale numerical simulation campaigns and machine learning techniques will be used to optimize the properties of the accelerated electrons. The interaction of these electron beams with various samples will be simulated with Monte Carlo code to assess their potential for applications such as Muon Tomography and radiobiology/radiotherapy. The proposed activity is essentially numerical, but with the possibility to be involved in the experimental activities of the team.

The PhD student will have the opportunity to be part of a dynamic team with strong national and international collaborations. They will also acquire the necessary skills to participate in laser-plasma interaction experiments in international facilities. Finally, they will acquire the required skills to contribute to the development of a complex software written in modern C++ and designed to run efficiently on the most powerful supercomputers in the world: the state-of-the-art Particle-In-Cell code WarpX (prix Gordon Bell en 2022). The development activity will be carried out in collaboration with the team led by Dr. J.-L. Vay at LBNL (US), where the candidate could have the opportunity to spend a few months during the thesis.
Attosecond dynamics of electrons and spins in 2D and 3D magnetic materials

SL-DRF-24-0246

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Dynamique et Interactions en phase COndensée (DICO)

Saclay

Contact :

Romain GENEAUX

Starting date : 01-10-2024

Contact :

Romain GENEAUX
CEA - DRF/IRAMIS/LIDyL/DICO

0169087886

Thesis supervisor :

Romain GENEAUX
CEA - DRF/IRAMIS/LIDyL/DICO

0169087886

Personal web page : https://iramis.cea.fr/Pisp/romain.geneaux/

Laboratory link : https://iramis.cea.fr/LIDYL/DICO/

Attosecond science focuses on the study of dynamics in matter at ultimate timescales, using light pulses of attosecond (10-18 s) duration. Our laboratory has pioneered the development and use of these pulses to investigate the ultrafast response of matter. In particular, we operate several platforms dedicated to attosecond spectroscopy of solids.

During this PhD project, we will develop original attosecond experiments aimed at elucidating the dynamics of one of the most important and intriguing degree of freedom of solids: the spins of its electrons. This quantity is responsible for the magnetic properties of materials, with applications ranging from data storage devices to spintronic components. Typically, existing devices use electric currents to convey and manipulate information.
Here, we aim to answer one apparently simple question: can we use a laser field, instead of a current, to control the electronic spins of a solid? While this would have the concrete potential of orders-of-magnitude faster operation, answering this question first requires fascinating fundamental investigations. Indeed, the response of magnetic materials at optical frequencies – below 10 fs – is almost completely unknown to this day. We propose to address this problem by performing experiments that combine spin sensitivity and attosecond resolution for the first time. By carefully shaping attosecond pulses and using state-of-the art detection schemes, we aim to establish a technique called attosecond magnetic dichroism, which will reveal the spin response of materials on the timescale of the electric field of light. We will first focus on simple tridimensional ferromagnetic and antiferromagnetic systems, before evolving towards their bi-dimensional counterparts. Indeed, so-called 2D materials are expected to provide enhanced, or even fundamentally novel light-spin interactions. By understanding how light interacts with electronic spins in 2D, we will provide key elements towards the integration of future low-dimensionality spintronic components.

The student will acquire practical knowledge about experimental ultrafast optics and of time resolved spectroscopy of condensed matter, especially magnetic materials. He/she will become an expert in attosecond physics and technology, as well as acquire valuable skills in complex data acquisition and analysis.
Attosecond high reprate spectroscopy of ultrafast photoemission of gases

SL-DRF-24-0345

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Attophysique (ATTO)

Saclay

Contact :

Pascal SALIERES

Starting date : 01-10-2024

Contact :

Pascal SALIERES
CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

Thesis supervisor :

Pascal SALIERES
CEA - DRF/IRAMIS/LIDyL/ATTO

0169086339

Personal web page : https://iramis.cea.fr/Pisp/pascal.salieres/

Laboratory link : http://iramis.cea.fr/LIDYL/

More : http://attolab.fr/

Summary :
The student will develop attosecond spectroscopy techniques making use of the new high reprate Ytterbium laser sources. The ultrafast photoemission dynamics will be studied to reveal in real time the processes of electron scattering/rearrangement as well as electron-ion quantum entanglement, using the charged-particle coincidence techniques.

Detailed summary :
In recent years, there has been spectacular progress in the generation of attosecond (1 as=10-18 s) pulses, rewarded by the 2023 Nobel Prize [1]. These ultrashort pulses are generated from the strong nonlinear interaction of short intense laser pulses with gas jets [2]. A new laser technology based on Ytterbium is emerging, with stability 5 times higher and reprate 10 times higher than the current Titanium:Sapphire technology. These new capabilities represent a revolution for the field.
This opens new prospects for the exploration of matter at the electron intrinsic timescale. Attosecond spectroscopy thus allows studying in real time the quantum process of photoemission, shooting the 3D movie of electronic wavepacket ejection [3,4], and studying quantum decoherence resulting from, e.g., electron-ion entanglement [5].
The first objective of the thesis work is to develop on the ATTOLab laser platform the attosecond spectroscopies using the new Ytterbium laser sources. The second objective is to take advantage of charged particle coincidence techniques, enabled by the high reprate, to study the dynamics of photoemission and quantum entanglement with unprecedented precision.
The student will be trained in ultrafast optics, atomic and molecular physics, quantum optics, and will acquire a broad mastery of XUV and charged-particle spectroscopy techniques.

References :
[1] https://www.nobelprize.org/prizes/physics/2023/summary/
[2] Y. Mairesse, et al., Science 302, 1540 (2003)
[3] V. Gruson, et al., Science 354, 734 (2016)
[4] A. Autuori, et al., Science Advances 8, eabl7594 (2022)
[5] C. Bourassin-Bouchet, et al., Phys. Rev. X 10, 031048 (2020)
Exploration of the energy deposition dynamic on short time scale with laser-driven electron accelerator in the context of the Flash effect in radiotherapy

SL-DRF-24-0351

Research field : Radiation-matter interactions
Location :

Service Laboratoire Interactions, Dynamique et Lasers (LIDyL)

Physique à Haute Intensité (PHI)

Saclay

Contact :

Gérard BALDACCHINO

Sandrine DOBOSZ DUFRÉNOY

Starting date : 01-10-2023

Contact :

Gérard BALDACCHINO
CEA - DRF/IRAMIS/LIDYL

01 69 08 57 02

Thesis supervisor :

Sandrine DOBOSZ DUFRÉNOY
CEA - DRF/IRAMIS/LIDyL/PHI

01.69.08.63.40

Personal web page : https://iramis.cea.fr/LIDYL/Phocea/Pisp/index.php?nom=gerard.baldacchino

Laboratory link : https://iramis.cea.fr/LIDYL/index.php

More : https://iramis.cea.fr/LIDYL/Phocea/Pisp/index.php?nom=sandrine.dobosz

The objective of the thesis project is to analyze the physicochemical processes resulting from the extreme dose rates that can now be obtained in water with the ultra-short (fs) pulses of relativistic electrons produced by laser-plasma acceleration. Indeed, first measurements show that these processes are probably not equivalent to those obtained with longer pulses (µs) in the FLASH effect used in radiotherapy. To achieve this, we propose to analyze the dynamics of formation/recombination of the hydrated electron, an emblematic species of water radiolysis, to qualify and quantify the dose rate effect over increasingly shorter times. This will be done in three stages in support of the necessary and now accessible technological progress, to have a dose per pulse sufficient to directly detect the hydrated electron. First, with the existing UHI100 facility, using the scavenging of the hydrated electron by producing a stable species; then producing a less stable but detectable species in real time and increasing the repetition rate of the electron source. Finally, by using an innovative concept named a “hybrid target”, based on a plasma mirror as an electron injector coupled to a laser-plasma accelerator, delivering larger doses with a narrower energy spectrum, we will be able to develop pump-probe detection allowing access to the shortest times, and to the formation in clusters of ionization, of the hydrated electron and measuring its initial yield.


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