Test of holographic SiC gratings for high-power synchrotron radiation

摘要

SiC laminar gratings have been fabricated by reactive ion-beam etching and holographic exposure. Diffraction efficiencies were measured in the region between 17 angstroms and 300 angstroms. The efficiency of the $PLU@1 order was 5 to 20% in this region with a small amount of scattered lights. An irradiation test for the SiC gratings was performed by using intense radiation with a power density of 2.7 W/mm$+2$/ emitted from a multipole wiggler installed into the 2.5 GeV Photon Factory ring. No visible damages and no reduction of the diffraction efficiencies were observed for the uncoated SiC grating after the irradiation, while a remarkable deformation of the deposited Au layer and increase of the scattered light component were observed for the grating coated with Au. In addition to these results, some experimental results of polishability of CVD-SiC are reported.