Use of Asymmetric Dynamical Diffraction of X-rays for Multiple-Crystal Arrangements of the (n₁, +n₂)Setting

Asymmetric dynamical diffractions of X-rays are successively used for multiple crystals arranged in the (n 1 , +n 2 ) setting. Double successive asymetric diffractions of the (n 1 , +n 2 ) arrangement give a beam of peculiar spread in angle and wavelength. Triple successive asymmetric diffractions of the (n, + n, - n) arrangement give a highly parallel and monochromatic beam for some appropriate combination of the asymmetry factors of the three crystals. Possible use of multiple asymmetric diffractions is discussed.