压弯镜系统自重平衡多点调节方法的研究

A study on multi-point gravity compensation of mirror bending system

本文分析同步辐射光束线压弯系统中镜子自重引起的面形误差,介绍减少重力不利影响的方法。根据梁变形理论,提出多点调节的重力平衡方法,并结合上海光源XAFS光束线(BL14W)中的准直镜压弯系统,得到其平衡力最佳的作用点和大小,计算出用两点、三点和四点调节自重平衡时,面形的均方根误差分别为0.179、0.067和0.032μrad。结果表明,比常用的两点调节方式,三点、四点调节的压弯镜自重引起的面形误差明显减小,在镜子面形误差和所受载荷方面,四点调节自重平衡法的效果更为优越。

The sag of mirror due to gravity induces unacceptable slope errors in beamline mirror-bending system of a synchrotron radiation facility, and approaches must be found to eliminate the unwanted gravity effect. According to the beam bending theory, the multi-point gravity compensation method is applicable. Taking an example of the bent collimating mirror for the XAFS beam-line （BL14W） at Shanghai Synchrotron Radiation Facility （SSRF）, the best position and value of the equilibrant were calculated through minimizing the gravity effect. With two, three and four points gravity compensation, slope errors were 0.179, 0.067 and 0.032 p.rad, respectively, i.e. the multi-point gravity compensation is better than the two-point gravity compensation, which is used for the Phase I beamlines of SSRF. The four-point gravity compensation method reduces more slope error and stress due to four support points.