Sub-millimeter synchrotron x-ray focusing by crystal bender

Abstract

Sagittal focusing is known as one of the most efficient focusing methods for synchrotron x-rays which increases the photon density at the sample position. Results are reported on the performance of a fixed height exit bender with an unribbed silicon (3 1 1) crystal. The fixed height exit was achieved by using a 4-point bending mechanism. This bending mechanism is designed for the SPring-8 standard double crystal monochromater (DCM) of bending-magnet beamlines. By using unribbed crystal, the focused beam size was kept at 0.5 mm in the energy range from 35–60 keV. A dynamical sagittal-focusing test was performed around Dy K-edge (53.787 keV). The results underline that 0.5-mm-focus size and beam position are kept during scanning energies; that is, the XAFS measurement can be performed with a sample size = 1 mm.