Seminars Archive

ESRF-EBS and spectroscopy: Examples with beamlines BM23 and ID24

Olivier Mathon
ESRF-France

Abstract
BM23 and ID24 are two ESRF beamlines dedicated to X-ray Absorption Spectroscopy (XAS). BM23 is a multi-purpose EXAFS beamline based on a two-poles wiggler source. BM23 is optimized for high quality XAS measurements between 5 and 90 keV, in transmission or fluorescence mode. ID24 is based on an undulator source and is composed of two branches, ID24-ED and ID24-DCM. ID24-ED is an energy dispersive XAS beamline, optimised for ultrafast XAS measurements down to the single bunch (100 ps), thanks to the high flux up to 1013 ph/s from the undulator source. The two main applications are the study of matter under high pulsed magnetic field (XAS and XMCD under pulsed field up to 30 Tesla and low temperature down to 2K) and the study of matter under laser induced dynamic compression, generated by the High Power Laser Facility (HPLF). ID24-DCM is a high brilliance XAS beamline based on a next generation scanning Double Crystal Monochromator (DCM). The accessible X-ray energy ranges from 5 to 45 keV. Taking advantage of the new EBS characteristics, this branch of ID24 beamline combines high flux up to 1013 ph/s from undulator source with variable X-ray beam size from 1x1 mm2 down to 500x500 nm2 FWHM. After a brief introduction of ESRF-EBS and spectroscopy activities at ESRF, I will describe the two beamlines and will highlight the main modifications performed in the setup following the implementation of the ESRF-EBS source. In particular, I will describe the choice of a new source for beamline BM23, the implication of the reduction of the horizontal emittance on the dispersive setup on optics (mirror and polychromator) and will describe in details the beamline ID24-DCM, a new beamline optimized for ESRF-EBS. I will present in particular the new DCM developed by ESRF and will provide some recent technical and scientific results obtained at BM23 and ID24-DCM using this monochromator.