基于固体探测器SDD的XAFS数据获取系统

DAQ system of XAFS based on solid detector SDD

X射线吸收精细结构谱学(X-ray Absorption Fine Structure,XAFS)的发展,提出了对低浓度(痕量)元素研究的需求,高灵敏度的固体探测器纷纷被应用到XAFS技术中来。硅漂移探测器(Silicon Drift Detector,SDD)是一种高计数率、高能量分辨率、采用半导体制冷的小型荧光探测器,其商业产品渐趋成熟。北京同步辐射装置1W2B实验站装备了这种小型SDD,并开发了相应采谱软件供用户使用。经过对含Cu 100 mg·L^(-1)浓度的CuSO_4溶液的测试,结果证明这套新的采谱系统可以满足1W2B实验站XAFS实验荧光模式的需求。

Background： Put forward the demands for low concentrations of elements in the X-ray absorption fine structure （XAFS） study on synchrotron radiation facility requires high sensitive solid state detectors. Silicon Drift Detector （SDD） is a small fluorescence detector that can be equipped with semiconductor refrigeration to achieve high count rate and high energy resolution. Its commercial products are becoming gradually mature.Purpose： This study aims to develop a small SDD based data acquisition （DAQ） system for XAFS beamline 1W2B experimental station at Beijing Synchrotron Radiation Facility （BSRF） and programmed the corresponding DAQ software for users.Methods：AXR-100FAST SDD from Amptek Inc was employed together with related electronics and ORTEC 974 counter for 1W2B experiment station. Corresponding DAQ software for user was developed using LabVIEW on the back-end control computer. CuSO4 solution containing Cu 100 mg＆#183;L？1 is prepared as a sample for testing this DAQ with SDD as detector, and Fourier transform of the radial distribution function is applied to experimental data analysis.Results： The final data shows information on the local structure of the first coordination of oxygen around Cu atoms. Conclusion： The test results of CuSO4 solution with concentration of 100 mg＆#183;L？1 proved that the new DAQ system equipped at 1W2B experimental station could satisfy the requirements of XAFS experiment fluorescence mode.