椭圆石英弯晶的积分衍射效率标定

摘要

椭圆弯晶谱仪具有测谱宽度大,能谱分辨力高等特点,并在"神光II"激光惯性约束聚变实验研究中得到了很好的应用.利用X射线衍射仪铜(Cu)靶X射线管作为X射线线光源,选取合适厚度滤片,抑制Cu-Kβ线及韧致辐射,测量了Cu-Kα能点处二氧化硅石英椭圆弯晶的积分衍射效率和摆动曲线半高全宽,并开展了针对上述两个重要参数随晶体弯曲曲率半径改变的测试验证,预估了能谱分辨力.结果表明,椭圆弯晶的积分衍射效率和摆动曲线半高全宽对晶体弯曲半径改变敏感,通过提高晶体弯曲度可增强晶体"镶嵌"效果.该结果可为下一步优化设计多用途性椭圆弯晶谱仪,以及完善X射线光谱定量化测量提供了数据支撑.%Elliptically curved crystal spectrometers exhibit large width of spectral measurement,high resolution of energy spectrum and other features,thus can be fully used in the experimental research on "SG II" Inertial Confinement Fusion(ICF).Taking advantage of X-ray tube of the copper(Cu)target for the X-ray diffractometer,and seleting appropriate thickness of filter disc to restrain Cu-Kβ ray and bremsstrahlung,parameters of integral diffraction efficiency and full width at half maximum of rocking curve for elliptically curved quartz crystal which was made from silicon dioxide at the Cu-Kα energy point were measured.In addition,a verification test aiming at the changes of curvature radius for curved crystal with the two above mentioned important parameters were performed,thus estimating the resolution of energy spectrum.The result shows that the integral diffraction efficiency of the elliptically curved crystal and full width at half maximum of rocking curve are sensitive to the change of the bending radius of the crystal.Therefore,the mosaic effect of crystal can be strengthened by improving the tortuosity of the crystal.The result can provide data support for further optimization of multi-purpose elliptical curved crystal spectrometer and quantitative measurement of X-ray spectrum.