Modified method for diffraction aberration of one-dimensional wire chamber
Modified method for diffraction aberration of one-dimensional wire chamber
复制标题
一维线室衍射像差的修正方法
DOI：
10.7498/aps.64.082901
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发表时间：
2015-04
影响因子：
1
通讯作者：
Shao Jian-Xiong
中科院分区：
文献类型：
--
作者：
Wei Kun;Zhang Jian;Ouyang Qun;Shao Jian-Xiong
一维位置敏感线气体探测器是针对同步辐射衍射而开发的，它由单根镀金钨丝和200个阴极条作为读出器组成。当X射线以高电压入射到阳极丝上时，几个相邻的阴极条产生感应信号。利用重心法对一维相邻信号进行分析，可以获得X射线的一次电离位置，位置分辨率为160μm（FWHM）。在北京同步辐射装置，衍射测试是在实验站进行的。当X射线照射SiO2晶体样品时，可产生不同尺寸的衍射环。测得衍射角为11.148。 14.201.，当探测器在衍射环范围内移动和扫描时，二维衍射环被重建。一维线室的衍射像差非常明显。文中讨论了探测器结构的相关影响因素。工作气体的厚度和有效区域窗口的宽度都会引起衍射环像差。衍射像差的理论计算值大于气体探测器的位置分辨率值。根据相应的物理分析建立了校正方法，并通过该方法计算出衍射环点的值。利用该方法，衍射位置的相对像差改善高达7％，并且可以重建无像差的二维衍射环。
The one-dimensional position sensitive wire gaseous detector is developed for the synchrotron radiation diffraction, which consists of a single wire of gold-plated tungsten and 200 cathode strips as the readout. The induced signal is produced by the several adjacent cathode strips when X-ray is incident on anode wire with high voltage. Using the center gravity method to analyze the adjacent signals in one dimension, the primary ionization position of the X-ray can be obtained and the position resolution is 160 mu m (FWHM). In Beijing Synchrotron Radiation Facility, the diffraction test is done at the experimental station. When the X-ray irradiates the crystal sample of SiO2, the different sizes of the diffraction rings can be produced. The diffraction angles are measured to be 11.148. and 14.201., and the two-dimensional diffraction rings are reconstructed when the detector is moved and scanned with the several steps in the diffraction ring range. The diffraction aberration of one-dimensional wire chamber is very obvious. In the paper, the relevant influence factors of the detector construct are discussed. The thickness of the working gas and the width of active area window can give rise to the diffraction ring aberration. The theoretical calculation value of the diffraction aberration is larger than the position resolution value of the gaseous detector. The correction method is established based on the corresponding physical analysis, and by this method the value of the diffraction ring point is calculated. The relative aberration of diffraction position is improved by up to 7% with using the method, and the two-dimensional diffraction ring with no aberration can be reconstructed.