2 MECHANICAL ASSEMBLY AND ACCURACY TESTING

A 132 pole elliptically polarizing undulator (EPU5.6) with magnetic period of 5.6 cm for production of brilliant and soft x-rays has been constructed and performed the field measurement at Synchrotron Radiation Research Center (SRRC). The "Apple-II" type device was selected for this EPU5.6 structure. The key factors in the construction and assembly process stage will be described. In addition, the shimming algorithm for the magnetic field adjustment, the performance of the mechanical structure, magnetic field distribution without the field shimming will be presented in this paper. Meanwhile, the control performance also will be discussed.