变形晶体X射线分光性能的数值模拟  

Numerical simulation of distorted crystal Darwin width

作　　者：王丽[1,2] 徐中民[1] 王纳秀[1] 

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院研究生院,北京100049

出　　处：《核技术》2012年第6期413-417,共5页Nuclear Techniques

基　　金：国家自然科学基金(11175243)资助

摘　　要：通过有限元软件计算同步辐射晶体单色器分光晶体的变形,确定晶体倒格矢的改变量,按变形晶体光学理论预测变形晶体的Darwin宽度,建立一套预测直接水冷却晶体单色器分光性能的方法。算得直接水冷晶体子午方向Darwin宽度展宽为4.12μrad,与采用晶体表面变形倾斜误差计算值(3.89μrad)相比更接近实验值(5.0μrad)。A new numerical simulation method according to distorted crystal optical theory was used to predict the direct-cooling crystal monochromator optical properties （crystal Darwin width） in this study. The finite element analysis software was used to calculate the deformated displacements of DCM crystal and to get the local reciprocal lattice vector of distorted crystal. The broadening of direct-cooling crystal Darwin width in meridional direction was estimated at 4.12 μrad. The result agrees well with the experimental data of 5 μrad, while it was 3.89 μrad by traditional calcultion method of root mean square （RMS） of the slope error in the center line of footprint. The new method provides important theoretical support for designing and processing of monochromator crystal for synchrotron radiation beamline.

关 键 词：双晶单色器 倒格矢 Darwin宽度 数值模拟 变形晶体 

分 类 号：TH744[机械工程—光学工程]