  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.

Instrumentation and Detectors;Materials Science;Optics