基于PILATUS探测器的von Hamos构型X射线发射谱谱仪及数据获取

Data acquisition system of a von Hamos X-ray emission spectrometer based on PILATUS detector

高能量分辨X射线发射谱(X-ray Emission Spectroscopy,XES)比常规X射线吸收精细结构谱(X-ray Absorption Fine Structure,XAFS)具有更高的能量分辨率,是探究物质精细电子结构的有力工具。PILATUS探测器是一种没有暗电流和读出噪声的单光子计数探测器,基于该探测器,在上海光源BL14W1线站搭建了一套von Hamos构型XES谱仪及数据获取系统,能量分辨率达到eV量级,接近此类构型光谱仪的世界先进水平。该光谱仪采用PILATUS探测器作为位置灵敏探测器使用,并结合线站单色器和KOHZU平台系统开发了一套基于LabVIEW软件的XES数据获取系统。对光谱仪系统进行了能量分辨率测试和CuO发射谱测量实验,获得样品发射的能量为8046 eV弹性散射峰的半高宽(Full-Widthat Half Maximum,FWHM)为1.67 eV,表明基于PILATUS探测器的von Hamos构型XES谱仪系统可以满足高能量分辨实验的需求。

[Background]High energy resolution X-ray emission spectroscopy(XES)has higher energy resolution than conventional X-ray absorption fine structure spectroscopy(XAFS),hence a powerful tool to explore the fine electronic structure of matter.The PILATUS detector is a single photon counting detector without dark current and readout noise.[Purpose]This study aims to build a von Hamos geometry high energy resolution XES and the data acquisition system(DAQ)at Shanghai Synchrotron Radiation Facility(SSRF)that can be used to combine multiple spectral methods and carry out the deep resolution of elements and the fine resolution of chemical forms.[Methods]The PILATUS detector was applied as a position sensitive detector and KOHZU stages were used to provide high precision adjustment of six dimensions of cylindrical curved crystal,an X-ray emission spectrometer based on von Hamos geometry was developed at BL14W1 beamline of SSRF.The data acquisition system of XES was developed based on a PILATUS detector,KOHZU stages,a monochromator and an ion chamber.The software of the spectrometer was developed on the LabVIEW platform and CAlab module.Resonant inelastic X-ray scattering(RIXS)and high energy resolution fluorescence detected X-ray absorption spectroscopy(HERFD-XAS)experiments were conducted to verify the performance of this XES.[Results]Results of energy resolution test and X-ray emission spectrum experiment of sample show that a resolution of 1.67 eV full-width at half maximum(FWHM)for elastic scattering peak of sample at 8046 eV is achieved,which is close to the world advanced level.[Conclusions]The von Hamos geometry X-ray emission spectrometer based on PILATUS detector meets the need of high energy resolution experiment at SSRF.