提高大口径金属主镜面形精度的方法

The Method for Improving the Surface Shape Accuracy of Large Metal Primary Mirror

分析了影响Ｒｉｔｃｈｅｙ－Ｃｈｒｅｔｉｅｎ光学系统中金属主反射镜面形精度因素，采用有限元法对主镜的加工过程及其安装进行了模拟。指出提高主镜的面形精度，既要合理主镜材料的热处理工艺，也要对加工参数进行控制。良好的稳定化处理可以有效地消除材料内部的残余应力，保证主镜尺寸的稳定性。提高加工基准的精度，并采用组合加工镜面，可以大大提高主镜的面形精度。最后。

The factors effecting the surface shape accuracy of the metal primary mirror in Ritchey Chretien optical system are anglyzed in the paper.The processing and the mounting conditions for the metal primary mirror are simulated by the finite element method.In order to obtain the high surface shape accuracy of the primary mirror,we must properly select the heat treatment technology and the machining process for the metal primary mirror.A good stabilization treatment can effectively eliminate the residual stress of the material and ensure the stability of the primary mirror sizes.The surface shape accuracy of the primary mirror can be greatly improved through raising the machining testplate accuracy and using the combined processing mirror surface.The testing results of the primary mirror obtained by interferometer are given in the end.