Simultaneous SAXS/SANS Method at D22 of ILL: Instrument Upgrade

Ezzeldin Metwalli,Christian Bär,Klaus Götz,Tobias Zech,Lionel Porcar,Anne Martel,Tobias Unruh,Isabel Schuldes

doi:10.3390/app11135925

Ezzeldin Metwalli, Christian Bär + Show 6 more

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https://doi.org/10.3390/app11135925

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Abstract

A customized portable SAXS instrument has recently been constructed, installed, and tested at the D22 SANS instrument at ILL. Technical characteristics of this newly established plug-and-play SAXS system have recently been reported (J. Appl. Cryst. 2020, 53, 722). An optimized lead shielding arrangement on the SAXS system and a double energy threshold X-ray detector have been further implemented to substantially suppress the unavoidable high-energy gamma radiation background on the X-ray detector. The performance of the upgraded SAXS instrument has been examined systematically by determining background suppression factors (SFs) at various experimental conditions, including different neutron beam collimation lengths and X-ray sample-to-detector distances (SDDX-ray). Improved signal-to-noise ratio SAXS data enables combined SAXS and SANS measurements for all possible experimental conditions at the D22 instrument. Both SAXS and SANS data from the same sample volume can be fitted simultaneously using a common structural model, allowing unambiguous interpretation of the scattering data. Importantly, advanced in situ/real time investigations are possible, where both the SAXS and the SANS data can reveal time-resolved complementary nanoscale structural information.

Highlights

Published: 25 June 2021Small angle scattering (SAS) of X-rays (SAXS) and neutrons (SANS) are non-destructive powerful techniques which have been utilized successfully for investigating nanostructured materials such as metal nanoparticles [1,2], emulsions [3], micelles [4,5], electrolytes [6,7], liquid crystals [8,9] and organic nanoparticles [10,11,12,13]
Background intensity measurements at the X-ray detector were measured at different experimental conditions, including neutron collimation lengths and SDDX-ray
For high signal-to-noise ratio SAXS data, it is important to minimize the background radiation level, both from neutrons scattered by the sample and from gamma rays produced by neutron absorption within the sample

Summary

Introduction

Published: 25 June 2021Small angle scattering (SAS) of X-rays (SAXS) and neutrons (SANS) are non-destructive powerful techniques which have been utilized successfully for investigating nanostructured materials such as metal nanoparticles [1,2], emulsions [3], micelles [4,5], electrolytes [6,7], liquid crystals [8,9] and organic nanoparticles [10,11,12,13]. SAXS and SANS methods are important tools for examining materials for various applications, e.g., solar cells, lithium-ion batteries and sensors [6,7,18,19,20,21] Combining both SAXS and SANS methods to investigate the same sample volume is remarkably advantageous, where two radiations offer two different contrast situations (X-ray and neutron scattering cross section). Using such multiple modalities is very beneficial, especially for cases when a single modality provides incomplete or ambiguous results.

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