Characterization of beryllium and CVD diamond for synchrotron radiation beamline windows and x-ray beam monitor

Abstract

We characterized beryllium foils and CVD diamond films/plates for synchrotron radiation beamline windows and x-ray beam monitor especially in coherent x-ray applications. Sub-micron-resolution imaging with a zooming tube was performed using spatially coherent x-rays at 1-km beamline 29XU of SPring-8. We found that the speckles observed in the conventional powder and ingot beryllium foils were due to voids with diameter of several to ten-several microns. The physical vapor deposition (PVD) eliminated the voids and the PVD beryllium showed the best performance with no speckles. We characterized a commercially available polycrystalline CVD diamond window and CVD films as well as beryllium foils. Polished thin diamond film showed rather uniform transmission image. We found dark spots at in-line image due to Bragg diffraction from grains for thicker CVD diamond window.