ISSP/SRL, Chiba
JASRI/SPring-8, Hyogo-ken
RIKEN Spring-8 Harima, Hyogo
A 27-m polarization-controlled undulator that consists of four horizontal and four vertical figure-8 undulator segments and seven phase shifters will be installed at SPring-8 as the most highly brilliant soft x-ray source for the material science beamline of the University of Tokyo. Each phase shifter controls the radiation phase between undulator segments by giving a bump orbit to the electron beam with its magnetic field to generate horizontal, vertical and circular polarization states. High reproducibility and stability of the phase control and fast helicity switching of the circular polarization radiation are required for the phase shifter. We designed and fabricated a phase shifter prototype to satisfy these requirements. The phase shifter prototype consists of three H-type dipole magnets and the yokes are made of 0.1-mm-thick permalloy laminations united and insulated by varnish. Various field measurements of the prototype were performed to evaluate the performance. In this paper, we will present the phase shifter prototype for the 27-m polarization-controlled undulator and its performance.
RIKEN/SPring-8, Hyogo
JASRI/SPring-8, Hyogo-ken
Several labs are pursuing the concept of cooling permanent magnet undulators down to cryogenic temperatures in order to increase the remnant field of the material and so the on-axis field strength. This talk will review the progress made in this field, experimental magnet field data will be available to show the real performance of such a device and show whether they can be built and shimmed at room temperature and operated at cryotemperatures.
