Holden William M, Hoidn Oliver R, Ditter Alexander S, Seidler Gerald T, Kas Joshua, Stein Jennifer L, Cossairt Brandi M, Kozimor Stosh A, Guo Jinghua, Ye Yifan, Marcus Matthew A, Fakra Sirine
Physics Department, University of Washington, Seattle, Washington 98195-1560, USA.
Chemistry Department, University of Washington, Seattle, Washington 98195-1560, USA.
Rev Sci Instrum. 2017 Jul;88(7):073904. doi: 10.1063/1.4994739.
X-ray emission spectroscopy is emerging as an important complement to x-ray absorption fine structure spectroscopy, providing a characterization of the occupied electronic density of states local to the species of interest. Here, we present details of the design and performance of a compact x-ray emission spectrometer that uses a dispersive refocusing Rowland (DRR) circle geometry to achieve excellent performance for the 2-2.5 keV range, i.e., especially for the K-edge emission from sulfur and phosphorous. The DRR approach allows high energy resolution even for unfocused x-ray sources. This property enables high count rates in laboratory studies, approaching those of insertion-device beamlines at third-generation synchrotrons, despite use of only a low-powered, conventional x-ray tube. The spectrometer, whose overall scale is set by use of a 10-cm diameter Rowland circle and a new small-pixel complementary metal-oxide-semiconductor x-ray camera, is easily portable to synchrotron or x-ray free electron laser beamlines. Photometrics from measurements at the Advanced Light Source show excellent overall instrumental efficiency. In addition, the compact size of this instrument lends itself to future multiplexing to gain large factors in net collection efficiency or its implementation in controlled gas gloveboxes either in the lab or in an endstation.
X射线发射光谱正成为X射线吸收精细结构光谱的重要补充,可对感兴趣物种的占据电子态密度进行表征。在此,我们介绍一种紧凑型X射线发射光谱仪的设计和性能细节,该光谱仪采用色散重聚焦罗兰(DRR)圆几何结构,在2 - 2.5 keV能量范围内实现了卓越性能,即特别适用于硫和磷的K边发射。DRR方法即使对于非聚焦X射线源也能实现高能量分辨率。这一特性使得在实验室研究中能够实现高计数率,尽管仅使用了低功率的传统X射线管,但其计数率接近第三代同步加速器中插入式装置光束线的计数率。该光谱仪的整体尺寸由一个直径10厘米的罗兰圆和一台新型小像素互补金属氧化物半导体X射线相机确定,便于携带至同步加速器或X射线自由电子激光光束线。在先进光源进行测量得到的光度学数据显示出仪器具有出色的整体效率。此外,该仪器的紧凑尺寸便于未来进行多路复用,以大幅提高净收集效率,或者在实验室或终端站的可控气体手套箱中使用。