AN SRRC ELLIPTICALLY POLARIZING UNDULATOR PROTOTYPE TO EXAMINE MECHANICAL DESIGN FEASIBILITY AND MAGNETIC-FIELD PERFORMANCE

In this work, a 1 m long Sasaki-type elliptically polarizing undulator (EPU) prototype with 5.6 cm period length is used to examine the mech anical design feasibility as well as magnetic held performance. The ma gnetic held characteristics of the EPU5.6 prototype at various phase s hifts and gap motion are described. The held errors from mechanical to lerances, magnet block errors, end held effects and phase/gap motion e ffects are analysed. The procedures related to correcting the held wit h the block position tuning, iron shimming and the trim blocks at both ends are outlined.