3x5 µm2 x-ray beam for high pressure spectroscopy experiments


As we seek to explore the properties of materials under extreme conditions, the high pressure spectroscopy station (16-ID-D) has commissioned a new focusing mirror system.  Near the middle of December 2015, the entire 16-ID-D hutch was re-configured to accommodate the bendable KB mirrors coated with Rh and Pt stripes on well-polished silicon.  The mirrors in Kirkpatrick-Baez geometry consist of a 320 mm long upstream vertical mirror and a 400 mm long downstream horizontal mirror, with a working distance of 250 mm.  Also a versatile pinhole positioner was installed in order to provide clean beam. As a result, the focus size at 11.56 keV incident beam, was 2.3 µm vertical x 5.0 µm horizontal in FWHM, with measured throughput very close to the design values.  The micron-sized focus capability enables the spectroscopy station to extend the range of pressures to multiple megabars for spectroscopy measurements in diamond anvil cells. (Key personnel: Stas Sinogeikin, Eric Rod, Yuming Xiao, Paul Chow)