Beamline 10: A multipole wiggler beamline at SSRL (invited)

Abstract

A beamline has been constructed at Stanford Synchrotron Radiation Laboratory (SSRL) whose radiation source is a multipole permanent magnet wiggler installed in a straight section of the SPEAR 3–3.5 GeV electron storage ring. The wiggler is a hybrid design that utilizes Nd–Fe alloy magnet material combined with Vanadium Permendur poles. It is approximately 2 m long and has 15 full wiggler periods. Its field is regulated by varying its gap height. It has a peak operating field, limited by the electron beam vacuum chamber vertical aperture, of 1.4 T. The beamline consists of vacuum, safety, and optical components capable of transporting photons to one hard x-ray (3–30 keV) end station, with provisions for implementing up to two additional branch lines. The existing hard x-ray branch can be focused by a Pt-coated toroidal mirror with a cutoff energy of approximately 22 keV. The experimental end station is serviced by a Hower–Brown type double crystal monochromator. The wiggler and beamline construction was completed in the fall of 1987 and was operated for a brief period for characterization and experimental use. We present design details and results of the initial characterization studies.