晶体单色器微调结构设计分析

Design and Analysis of Crystal Monochromator Trimming Structure Design

为了利用同步辐射单色光研究生物细胞、病毒等以促进生物医药学的发展,对输出单色光的晶体单色器的主要结构(微调结构)进行了设计分析.根据实际的应用要求,单色器只输出三个能量点分别为2.1keV、2.3keV和2.5keV的光束线,能量分辨率Δ≤5×10-4,角度重复精度小于3″,微调结构采用三块独立的切槽型晶体,设计了晶体安装座、柔性铰链和推杆等,利用步进电机实现晶体角度的精确微调.步进电机朝一个方向转到预设的光栅尺数值,并与自准直仪的监测数值比较.测试结果表明:角度微调的10次移动过程中,最大偏差2.79″,最小偏差-1.87″,满足重复精度小于3″的设计指标.

In order to study the mechanism of biological cells and viruses by the synchrotron radiation monochromatic light,the main structure of the crystal monochromator which outputs monochromatic light was designed and analyzed.According to the actual application,this monochromator output the beam lines of three energy points：2.1keV,2.3keV and 2.5keV.The energy resolution wasΔ≤5×10-4,and the repeatability of angle was less than 3″.The fine structure of the crystal monochromator included three separate cutting groove-typed crystals.And the crystal mounting base,flexible hinge,and the push rod were cleverly designed.The crystal angle was tuned precisely by a stepper motor.The stepper motor was turned in one direction to the preset value of grating,which was compared with the monitoring data by the autocollimator.The test results show that,in the process of 10 times of angle trimming,the maximum deviation is 2.79″,the minimum deviation is-1.87″which meet the design specification that the repeatability needs to be less than 3″.