title: An SRRC elliptically polarizing undulator prototype to examine mechanical design feasibility and magnetic field performance.
abstract: 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 mechanical design feasibility as well as magnetic field performance. The magnetic field characteristics of the EPU5.6 prototype at various phase shifts and gap motion are described. The field errors from mechanical tolerances, magnet block errors, end field effects and phase/gap motion effects are analysed. The procedures related to correcting the field with the block position tuning, iron shimming and the trim blocks at both ends are outlined.
authors.affiliation: Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan.
authors.forename: C H
authors.initials: CH
authors.lastname: Chang
authors.forename: C S
authors.initials: CS
authors.lastname: Hwang
authors.forename: T C
authors.initials: TC
authors.lastname: Fan
authors.forename: K H
authors.initials: KH
authors.lastname: Chen
authors.forename: K T
authors.initials: KT
authors.lastname: Pan
authors.forename: F Y
authors.initials: FY
authors.lastname: Lin
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: L H
authors.initials: LH
authors.lastname: Chang
authors.forename: H H
authors.initials: HH
authors.lastname: Chen
authors.forename: M C
authors.initials: MC
authors.lastname: Lin
authors.forename: S
authors.initials: S
authors.lastname: Yeh