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A high sensitivity Small Angle X-Ray Scattering (SAXS) experiment
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3D view aof the design

We designed and regulary upgrading an home made SAXS experiment for high sensitivity measurements.

The generator is a copper rotating anode Rigaku RUH3R, with a fine focus filament.

Optic is composed by an Xenocs collimating multilayer mirror, coupled with home made hybrid cristal slits.

The distance between source and sample is around 200 cm. We take attention to reduce the air quantities between the sample and the vacuum chamber. In this way we designed an retractable nose, let us change the sample environment. We can propose multi-position capillary holder, powder holder, heating system, thermostated system, circulation chamber,...

The beam size on the sample is 0.8 mm x 0.8 mm and the flux around 100x106 ph/s.

The vacuum chamber is containing a beamstop with a small calibrated photodiode.

Distance between the detector is 120 cm, and the q range is from less to 10-2 Å-1 to 0.7 Å-1.

 

What is measured in a Small Angle X-ray Scattering (SAXS) ?

 

View of the sample position

Detector :

We use a Mar 300, automatic image plate reader, that produce a good resolution (0.150 mm), a good sensitivity (efficienty around 90%), but a high background level.

Is some cases we can use a gas detector, with a very low background level.

 

Multi position capillary sample holder, and a view of the retractable nose.

Reference samples :

- lupolen is a solid polymer, wich produce a slope at I=6cm-1

- tetradecanol, or commonly myristyl alcohol, is a straight-chain saturated fatty alcohol, with the molecular formula C14H30O, and organized as a well structrured  lamellar phases. SAXS spectra gives very fine peaks. First order is 0.1581 Å-1

Data treatment

We developed two software for the data treament :

- for the image reduction, we use ImageJ plugins

- for the spectrum treatment, we use pySAXS

 

Maj : 11/09/2012 (183)

 

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