High energy resolution five-crystal spectrometer for high quality fluorescence and absorption measurements on an X-ray Absorption Spectroscopy beamline

Isabelle Llorens (1) , Eric Lahera (2) , William Delnet (2) , Olivier Proux (2) , Aurélien Braillard , Jean-Louis Hazemann (3) , Alain Prat (4) , Denis Testemale (3) , Quentin Dermigny (5) , Frédéric Gélébart (5) , Marc Morand (5) , Abhay Shukla (5) , Nathalie Bardou (6) , Olivier Ulrich (7) , Stephan Arnaud (8) , Jean-François Bérar (8) , Nathalie Boudet (8) , Bernard Caillot (8) , Perrine Chaurand (9) , Jérôme Rose (9) , Emmanuel Doelsch (10) , Philippe Martin (11) , Pier Lorenzo Solari (1)

1 SSOLEIL - Synchrotron SOLEIL
2 équipe FAME
3 NEEL - MRS - Matériaux, Rayonnements, Structure
4 NEEL - X'Press - X'Press : diffraction et hautes pressions
5 IMPMC - Institut de minéralogie et de physique des milieux condensés
6 LPN - Laboratoire de photonique et de nanostructures
7 SP2M - UMR 9002 - Service de Physique des Matériaux et Microstructures
8 NEEL - CRG - CRG & Grands instruments
9 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
10 UPR Recyclage et risque - Recyclage et risque
11 LM2C - Laboratoire de Modélisation Multi-échelles des Combustibles

Fluorescence detection is classically achieved with a solid state detector (SSD) on x-ray absorption spectroscopy (XAS) beamlines. This kind of detection however presents some limitations related to the limited energy resolution and saturation. Crystal analyzer spectrometers (CAS) based on a Johann-type geometry have been developed to overcome these limitations. We have tested and installed such a system on the BM30B/CRG-FAME XAS beamline at the ESRF dedicated to the structural investigation of very dilute systems in environmental, material and biological sciences. The spectrometer has been designed to be a mobile device for easy integration in multi-purpose hard x-ray synchrotron beamlines or even with a laboratory x-ray source. The CAS allows to collect x-ray photons from a large solid angle with five spherically bent crystals. It will cover a large energy range allowing to probe fluorescence lines characteristic of all the elements from Ca (Z = 20) to U (Z = 92). It provides an energy resolution of 1-2 eV. XAS spectroscopy is the main application of this device even if other spectroscopic techniques (RIXS, XES, XRS, etc.) can be also achieved with it. The performances of the CAS are illustrated by two experiments that are difficult or impossible to perform with SSD and the complementarity of the CAS vs SSD detectors is discussed.

Mots clés: X-ray spectroscopy; X-ray absorption spectra; synchrotrons; fluorescence spectroscopy

Domaines: Instrumentations et Détecteurs [physics.ins-det]

Isabelle Llorens, Eric Lahera, William Delnet, Olivier Proux, Aurélien Braillard, et al.. High energy resolution five-crystal spectrometer for high quality fluorescence and absorption measurements on an X-ray Absorption Spectroscopy beamline. Review of Scientific Instruments, 2012, 83 (6), pp.063104. ⟨10.1063/1.4728414⟩. ⟨insu-00708404⟩