Performance of the SPring-8 modular piezoelectric bimorph mirror prototype

Abstract

This paper reports on the performances of a test prototype mirror, based on the Piezoelectric Bimorph Mirror technology, which has been designed and manufactured (in collaboration with the French optical company SESO) for the national Japanese 8 GeV storage ring SPring-8. The device consists of two 150 mm long modules assembled sideby-side. It exhibits superior surface quality with respect to previously manufactured long piezoelectric bimorph mirrors, as the junctions between modules do not introduce any distortion on the reflecting surface. The mirror can effectively compensate low frequency components of the figure error/waviness left by polishing. Two different simple optimisation methods have been validated: "ex-situ" in the metrology lab (Adaptive Optics correction & control algorithm) and, for the first time, "in-situ" at the beamline (Hartmann test). After optimisation with coherent x-rays at the 1 km long SPring-8 beamline, elliptical shaping was achieved with sub prad level precision for the slope error rms. The associated height error is as small as 8 nm rms. over 200 mm illuminated length. An extremely sharp and gaussian 8 im FWHM wide spot size was obtained by vertically demagnifying the undulator source. It has also been demonstrated that it is possible to bend the mirror to an arbitrary, user-defined, shape; i.e. sinusoidal.

Pressure-induced transition in titanium metal: a systematic study of the effects of uniaxial stress

“…The monochromatic x-ray beam was focused down, using multilayer bimorph mirrors in a Kickpatrick-Baez configuration [28,29], to 10 µm by 10 µm. Diffraction images were recorded during 30 sec.…”

Melting of tantalum at high pressure determined by angle dispersive x-ray diffraction in a double-sided laser-heated diamond-anvil cell

“…Angle-dispersive x -ray diffraction measurements of Ta under high pressure and high temperature were performed in a double-sided laserheated symmetric DAC (with flat diamonds with culet sizes ranging from 300 to 500 µm) at the 16ID -B undulator beamline of the High Pressure Collaborative Access . The monochromatic x-ray beam was focused down, using multilayer bimorph mirrors in a Kickpatrick-Baez configuration [33,34], to 10 µm by 10 µm.…”

Active x-ray optics for Generation-X, the next high resolution x-ray observatory

“…The program was motivated by the need to illuminate small samples without irradiating their surroundings. This program, led by R. Signorato (Signorato et al , 2004, has developed increasingly complex piezo controlled X-ray mirrors using a design of pairs of piezos acting oppositely, which removes temperature effects. As a result they call their designs 'Piezoelectric Bi-morph Mirrors' (PBMs).…”