Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving x-ray crystal optics

We report fabrication and results of high-resolution X-ray topography characterization of diamond single crystal plates with a large surface area (10$\times$10 mm$^2$) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics. The plates were fabricated by laser cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature method. The intrinsic crystal quality of a selected 3$\times$7~mm$^2$ crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. The wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking curve topography. The variation of the rocking curve width and peak position measured with a spatial resolution of 13$\times$13 $\mu m^2$ over the selected region were found to be less than one microradian.