1D X-ray beam compressing monochromators

A total beam compression of 5 and 10 corresponding to the asymmetry angles of 9° and 12° is achieved with V-5 and V-10 monochromators, respectively, in standard single crystal pure germanium (220) X-ray beam compressing (V-shaped) monochromators for CuK?1 radiation. A higher 1D compression of X-ray beam is possible using larger angles of asymmetry, however it is achieved at the expense of the total intensity, which is decreased due to the refraction effect. To increase the monochromator intensity, several ways are considered both theoretically and experimentally. Linearly graded germanium rich GexSi(1-x) single crystal was used to prepare a V-21 single crystal monochromator with 15° asymmetry angles (compression factor of 21). Its temperature gradient version is discussed for CuK?1 radiation. X-ray diffraction measurements on the graded GeSi monochromator showed more than 3-times higher intensity at the output compared with that of a pure Ge monochromator.