Integrated instrumentation for combined polarized single-crystal XAS and diffraction data acquisition for biological applications

Single-crystal X-ray absorption spectroscopy (XAS) instrumentation, allowing sequential integrated XAS and crystallographic data acquisition during the same experiment and on the same beamline, has been developed for SSRL beamline 9-3, a wiggler side station dedicated to general user biological XAS. The implementation includes a Huber kappa goniometer, Canberra 30-element Ge detector for XAS data collection, open-flow LHe and LN₂ crystal coolers, a microscope for crystal alignment in the beam, and a MarCCD crystallography detector. The kappa goniometer allows a large accessible angular range with an open geometry, affording access to detectors and open stream coolers, as well as future instrumentation. Applicable standard hardware on SSRL crystallography beamlines has been incorporated, with crystallographic data collection controlled via the Blu-Ice software developed by the SSRL SMB macromolecular crystallography group. XAS data collection is handled through the SSRL standard XAS-Collect software. Initial diffraction and XAS data from single crystals using an open-flow cryostat are presented. The instrument will be available to general users after the SPEAR3 upgrade in 2004, and future expansion for use in high-throughput structural genomics XAS is proposed.