光栅单色器中精密直线位移的测试与标定系统

A system to measure and calibrate linear displacement of grating monochromators at BSRF

在同步辐射光束线建设中,为达到单色器的光谱分辨率要求,对波长扫描机构的定位精度要求在μm量级。我们建立的由激光干涉仪、自准直仪组成的直线位移测试系统,可以对直线位移机构进行测试并对机构的直线位移编码器进行标定。该系统不但实现了直线位移的精密测量,还能对机构的直线性进行测量。应用该系统测出位移范围为160mm的直线位移机构的重复精度为1.0×10-3mm,分辨率达7.5×10-5mm,对光栅尺的标定精度达到RMS=3.0×10-4mm。

High accuracy linear movement in grating monochromators of synchrotron radiation beamline is essential. Usually the linear displacement accuracy requirement is about 1 micron to achieve the spectral resolution. A laser interferometer and an autocollimator are used Beijing Synchrotron Radiation Facility （BSRF） to measure linear displacement of the mechanism and to calibrate the linear encoder. It measures not only precision of the linear displacement, but also linearity of the movement. Linear displacement mechanism was tested by the system with accuracy of 1.0×10^-3 mm and resolution of 7.5×10^-5 mm. The linear encoder can give the displacement at an accuracy of RMS=3×10^-4 mm within 160 mm range. This system plays an important role for both linear displacement mechanism commissioning and for wavelength calibration of the monochromators.