NEW SOFT-ENERGY X-RAY ABSORPTION SPECTROSCOPY INSTRUMENT

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. A new instrument for XAS measurements in the 2-5 keV range was completed and commissioned. In this energy range, x-rays have a very short path length in air and thus the entire beam path is enclosed in a helium atmosphere to enable data collection. The new setup incorporates several features to improve efficiency and ease of use. These includes computer-controlled motorized x-ray slits, a motorized linear motion feed-through (which has both a fluorescent screen for sample alignment and a reference calibrant for external calibration), and a computer-controlled shutter to close off the beam between data points (to reduce x-ray induced damage to samples). Oxygen sensors and flowmeters are utilized for monitoring the purity of the helium atmosphere. A LHe cryostream has been successfully implemented to cool the samples in order to minimize radiation damage. The new design allows the instrument to be installed at beam lines other than BL6-2.