title: An ultrahigh-vacuum apparatus for resonant diffraction experiments using soft x rays (hnu=300-2000 eV).
abstract: We have developed an ultrahigh-vacuum instrument for resonant diffraction experiments using polarized soft x rays in the energy range of hnu=300-2000 eV at beamline BL17SU of SPring-8. The diffractometer consists of modified differentially pumped rotary feedthroughs for theta-2theta stages, a sample manipulator with motor-controlled x-y-z-, tilt (chi)-, and azimuth (phi)-axes, and a liquid helium flow-type cryostat for temperature dependent measurements between 30 and 300 K. Test results indicate that the diffractometer exhibits high reproducibility (better than 0.001 degrees ) for a Bragg reflection of alpha-quartz 100 at a photon energy of hnu=1950 eV. Typical off- and on-resonance Bragg reflections in the energy range of 530-1950 eV could be measured using the apparatus. The results show that x-ray diffraction experiments with energy-, azimuth-, and incident photon polarization-dependence can be reliably measured using soft x rays in the energy range of approximately 300-2000 eV. The facility can be used for resonant diffraction experiments across the L-edge of transition metals, M-edge of lanthanides, and up to the Si K-edge of materials.
authors.affiliation: RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
authors.forename: A
authors.initials: A
authors.lastname: Chainani
authors.forename: Y
authors.initials: Y
authors.lastname: Takata
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Oura
authors.forename: M
authors.initials: M
authors.lastname: Tsubota
authors.forename: Y
authors.initials: Y
authors.lastname: Senba
authors.forename: H
authors.initials: H
authors.lastname: Ohashi
authors.forename: T
authors.initials: T
authors.lastname: Mochiku
authors.forename: K
authors.initials: K
authors.lastname: Hirata
authors.forename: S
authors.initials: S
authors.lastname: Shin