A novel crystal bender for x-ray synchrotron radiation monochromators

Abstract

A new bending mechanism for an indirectly water cooled monochromator crystal has been developed. The main design goals were a lightweight construction, ease of manufacture, and control. The construction consists of a U-shaped first Si(111) crystal, which can be bent by compressed air to compensate the bowing induced by the heat load from the impinging white synchrotron radiation. The performance of the system was tested at the x-ray undulator beamline BW1 at HASYLAB (Hamburg, Germany). For heat loads between ∼100 and 400 W, rebending of the crystal significantly increases the intensity of the monochromatic beam while the rocking curve is narrowed accordingly, typical widths obtained at 8.9 keV photon energy amount to about 10 arc sec.

The materials science X-ray beamline BL8 at the DELTA storage ring

“…Both goniometers can be adjusted vertically by about 50 mm to the variable first mirror pitch. All the first crystals are indirectly water cooled, with the cooling being designed for heat loads of up to 500 W. For the Si(111) and the Si(311) crystals, the cooling is combined with a bending mechanism to compensate for the thermal bump induced by the high heat load of the wiggler (Zaeper et al, 2002). For this purpose the legs of the U-shaped crystals [80 mm  80 mm (length  width) of the reflecting Si surfaces] can be spread by a metal bellow actuated by compressed air, thereby increasing the Bragg-reflected intensities and narrowing the corresponding rocking curves (Zaeper et al, 2002;Dudzik et al, 2006).…”

The new HMI beamline MAGS: an instrument for hard X-ray diffraction at BESSY

“…The goniometer can be moved vertically by 50 mm to adjust to the changing first-mirror pitch. The first crystal is indirectly watercooled, with the cooling designed for heat loads up to 600 W. The cooling is combined with a counterbending mechanism to compensate the thermal bump from the wiggler beam (Zaeper et al, 2002). This bender was built by ACCEL in collaboration with the University of Wuppertal, Germany.…”

Research on a logarithmically bent Laue crystal analyzer for X-ray monochromatic backlight imaging

“…[1][2][3] The key components of these imaging spectrometers are generally spherically bent Bragg crystals. [4][5][6] However, the configurations using spherically bent crystals always encounter the geometric constraints that arise from the fact that the Bragg angles of the spherically bent crystals are limited to angles larger than 45 •7 and must be greater than 80 • to limit astigmatism. 8 One possible solution of the problem is to use toroidally bent crystals.…”