title: Transmissive x-ray beam position monitors with submicron position- and submillisecond time resolution.
abstract: We present the development of fast transmissive center-of-mass x-ray beam position monitors with a large active area, based on a thinned position sensitive detector in both a duo- and a tetra-lateral variant. The detectors were tested at BESSY beamlines BL14.1, KMC-1, and KMC-2 and yielded signal currents of up to 3 microA/100 mA ring current at 10 keV photon energy using the monochromatic focused beam of BL14.1. The active area sizes were 1 x 1 and 3 x 3 mm(2) for the duo-lateral and 5 x 5 mm(2) for the tetra-lateral devices, with the duo-lateral detectors currently being available in sizes from 1 x 1 to 10 x 10 mm(2) and thicknesses between 5 and 10 microm. The presented detectors' thicknesses were measured to be 5 and 8 microm with a corresponding transmission of up to 93% at 10 keV and 15% at 2.5 keV. Up to a detection bandwidth of 10 kHz, the monitors provide submicron position resolution. For lower detection bandwidths, the signal-to-noise reaches values of up to 6 x 10(4) at 10 Hz, corresponding to a position resolution of better than 50 nm for both detector sizes. As it stands, this monitor design approach promises to be a generic solution for automation of state-of-the-art crystal monochromator beamlines.
authors.affiliation: BESSY GmbH, Berlin, Germany.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Fuchs
authors.forename: Karsten
authors.initials: K
authors.lastname: Holldack
authors.forename: Mark
authors.initials: M
authors.lastname: Bullough
authors.forename: Susanne
authors.initials: S
authors.lastname: Walsh
authors.forename: Colin
authors.initials: C
authors.lastname: Wilburn
authors.forename: Alexei
authors.initials: A
authors.lastname: Erko
authors.forename: Franz
authors.initials: F
authors.lastname: Schäfers
authors.forename: Uwe
authors.initials: U
authors.lastname: Mueller
mesh_terms: D018360:Crystallography, X-Ray / Q000295:instrumentation*; D004583:Electrons; D017785:Photons; D014965:X-Rays