A Novel Beam-Conditioning Monochromator for High-Resolution X-ray Diffraction

This paper describes a novel duMond-configuration monochromator for high-resolution X-ray diffraction. The device consists of two single-crystal blocks of silicon each containing two beam channels cut respectively parallel to and 17.65° from the (011) planes. In the high-intensity mode, with Cu Kα₁, radiation, the beam divergence is 11.5" and the dispersion is 1.3 × 10⁻⁴ with intensity comparable with that from a symmetric Ge 022 device. The high-resolution setting has a divergence of 4.4" and dispersion of 4.9 × 10⁻⁵, the intensity being a factor of ten lower than in the high-intensity setting. Parallel lateral translation of the two elements permits a rapid switch between the high-resolution and high-intensity settings.