HU, HC (reprint author), CHINA INST ATOM ENERGY,POB 275 18,BEIJING 102413,PEOPLES R CHINA.
Exact solutions of power transfer equations for plane-parallel and bent crystals in symmetric and asymmetric Bragg and Laue geometries are obtained, for the nonabsorbing case. Conceptual and mathematical errors in the solutions for asymmetric diffraction given by Bacon & Lowde [Acta Cryst. (1948), 1, 303-314] are pointed out. A very significant result is that, for asymmetrical Laue geometry, over 50% reflecting power is proved to be possible when b < 1. The integrated reflecting power and expressions for the optimum value of the curvature radius for bent mosaic crystals in the Bragg and Laue cases are also given.