NEW SOFT-ENERGY X-RAY ABSORPTION SPECTROSCOPY INSTRUMENT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 2007年投入使用了一台用于2-5keV范围内XAS测量的新仪器，并在2008年为BL4-3建造和实施了进一步增强的装置。在这个能量范围内，X射线在空气中的路径长度非常短，因此整个光束路径被封闭在氦大气中，以便能够进行数据收集。这些设置结合了几个功能，以提高效率和易用性。这包括计算机控制的电动X射线狭缝，电动直线运动馈送，以及计算机控制的快门，以关闭数据点之间的光束(以减少X射线对样品的损害)。氧传感器和流量计被用来监测氦大气的纯度。LHe冷流现在被常规用于将样品冷却到~50K，计划对冷却设置进行修改，以提高易用性，并允许更好地隔热探测器。

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 commissioned in 2007 and during 2008 a further enhanced setup was constructed and implemented for BL4-3. 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. These setups incorporate several features to improve efficiency and ease of use. This includes computer-controlled motorized x-ray slits, a motorized linear motion feed-through, 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 is now in routine use for cooling samples to ~50 K. Modifications of the cooling setup are planned to improve ease of use and allow for better thermal isolation of the detector.