Instrumentation Developments for X-ray Linear and Circular Dichroism at the ESRF Beamline ID12A

Abstract

This paper reports on the performance of the instrumentation developed for the ESRF beamline ID12A, which is dedicated to spectroscopic applications requiring full control of the polarization at energies >/=2.0 keV. Emphasis is placed on the characterization of various optical components of the beamline and on problems associated with either the control or the conversion of the polarization state. A few examples have been selected to illustrate what sort of new spectroscopic information has already been obtained at the beamline. These include the comparison of X-ray magnetic dichroism spectra recorded with linear or circular polarization and the very first detection of X-ray natural circular dichroism in single crystals known to exhibit a very large non-linear susceptibility at optical wavelengths.

Structural relaxations around Ti, Cr and Fe impurities in α-Al2O3probed by x-ray absorption near-edge structure combined with first-principles calculations

“…X-ray absorption measurements X-ray absorption measurements are carried out at the European Synchrotron Radiation Facility (ESRF) on the ID12 beam line, which is dedicated to polarization dependent spectroscopies. 10,11 The monochromatic x-ray beam is obtained through a double Si(111) crystal monochromator, with a resolution ∆E/E ≃ 10 −4 . The oriented samples are placed on a rotating holder with the normal of the disk surface parallel to the x-ray wave vector and to the rotation axis.…”

Natural linear dichroism in pyrite (FeS2): experiments and calculations

“…As was noticed by Dräger et al (1988) The experimental data were collected at the ESRF beam line ID12-A, dedicated to polarisation dependent spectroscopies (Goulon et al, 1998). The absorption is measured by eight photodiode fluorescence detectors symmetrically set around the X-ray wave vector.…”

X-ray magnetic reflectometry using circularly polarized radiation

“…The double-bounce re¯ectometer was installed in the`white beam experimental station' (see Fig. 1 in Goulon et al, 1998). The incident beam was collimated using water-cooled secondary slits located before the re¯ectometer and closed down to 400 (V) Â 250 (H) mm.…”