Computer-simulated X-ray three-beam pinhole topographs for spherical silicon crystals.

X-ray three-beam pinhole topograph images for spherical silicon crystals were computer-simulated based on the n-beam Takagi-Taupin (T-T) equation. They were compared with those for parallel-plate crystals. The procedure to integrate the n-beam T-T equation for a crystal with an arbitrary shape has been validated in a separate paper [Okitsu et al. (2011), Acta Cryst. A67, 550-556] from comparison between experimentally obtained and computer-simulated six-beam pinhole topographs for a channel-cut silicon crystal.