上海光源可变椭圆极化波荡器积分场垫补

Field integral shimming of elliptically polarized undulator at Shanghai synchrotron radiation facility

详细介绍了上海光源波荡器EPU100积分场多极分量和一、二次积分的垫补及优化计算方法,其中的积分场多极分量采用"Magic Fingers"技术,即:在插入件两端部中平面上下使用一组适当的磁柱组合来抵消积分场误差;一、二次积分采用两端部的8个调补线圈垫补。通过垫补,EPU100在全磁隙,各种极化模式下四极分量小于9×10-3T,六极分量小于1.6 T/m,八极分量小于30 T/m2,达到了设计指标。

This paper discusses the shimming and the optimization algorithm of the integrated multipoles and the first and second field integrals of the EPU100 at Shanghai synchrotron radiation facility. To shim the integrated muhipoles, the ＂Magic Fingers＂ technique is used, which is a proper arrangement of small magnet cylinders to reduce variation of the field integral errors; and the 8 trimming coils installed at the two ends of the undulator are used to shim the first and second field integrals. After shim-ming all the operating gaps or polarized modes of the EPU100, the quadrupole component is less than 9×10^-3 T, the sextupole component is less than 1.6 T/m, and the octupole component is less than 30 T/m^2 , the muhipole components are all well within the specifications.