COMMISSIONING OF A CRYSTAL ANALYZER FOR INELASTIC SCATTERING AND ADVANCED SPECTR

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. An instrument for inelastic x-ray scattering and advanced spectroscopic measurements (including x-ray emission spectroscopy and site-selective EXAFS spectroscopy) was further developed. The first Resonant inelastic x-ray scattering (RIXS) measurements were made using this setup on SSRL BL6-2. A set of three Ge(110) analyzers were used for measurement of Fe K-alpha emission. Using Si(111) crystals as beam line monochromator, a total energy resolution of ~1.1 eV was measured at 6.4 keV. Assuming a Darwin width of 0.9 eV at 6.4 keV for Si(111) crystals, this indicates that the Ge(110) analyzer crystals have a resolution of better than 0.7 eV. In addition to this set of analyzers, a set of three Si(553) crystals was used to obtain Cu Kbeta" XES data. This was the second time this setup was used for Cu Kbeta" XES, and a resolution of better than 1 eV for these measurements was obtained. The RIXS and XES data from these measurements are being analyzed. Finally a newly purchased set of three Ge(111) analyzers was used in a study of range extended Mn EXAFS (beyond the Fe K edge) of the oxygen evolving complex of photosystem II. This experiment was performed at beam line 18ID at the Advanced Photon Source. We are planning to move the extended range experiments to SSRL when SPEAR3 is running at 500 mA.