X-Ray Crystal Collimators Using Successive Asymmetric Diffractions and Their Applications to Measurements of Diffraction Curves. III. Type II Collimator

Abstract

New type monolithic crystal collimators for 422 and 511 reflections of CuK_α1 using successive asymmetric diffractions are constructed and applied to precise measurements of diffraction curves from silicon crystals with a double-crystal diffractometer of parallel setting. The collimator consists of two crystal components and the second component is rotated to eliminate the deviation of the beam direction from the diffraction condition for second component, which is caused by refraction. Thus he beam intensity obtained for 422 becomes 35 times stronger than the case where the second component is not rotated. The angular spreads of the beams obtained are 0.10″ for 422 and 0.07″ for 511. For the symmetric Bragg-case diffractions, the observed (calculated) half-value widths and reflection percents are 2.944″±0.004″ (2.946″) and 94% (94.7%) for 422, and 1.998″±0.003″ (2.000″) and 87% (88.4%) for 333, respectively.