Misalignment sensitivity of an inclinedcrystal monochromator
Abstract
The sensitivity of a novel inclinedcrystal monochromator design to misalignments has been calculated, and compared to data. Rocking curve narrowing as well as broadening can occur because the asymmetry factor of dynamical diffraction given by b= s_{0}· n/ s_{H}· n can have absolute value largeror smaller than unity. Here s_{0}· n and s_{0}· n are the direction cosines of the incident and diffracted beams, respectively, and n is the inward surface normal. An inclined double crystall monochromator that is perfectly aligned would have b=1 for both crystals, and only then would the diffraction be symmetric. We have computed b and rocking curve widths for inclination angles of 70.53° and 85.00°, and we compare the 70.53° case to data for silicon {111] reflections using 8 keV (CuKα) radiation. The 70.53° case applies to ( 11 overline1) reflection from a (111) oriented crystal. We report that rotations around the reciprocal lattice vector have the expected effect on b.
 Publication:

Nuclear Instruments and Methods in Physics Research A
 Pub Date:
 August 1992
 DOI:
 10.1016/01689002(92)90547H
 Bibcode:
 1992NIMPA.319..155M