The three-dimensional resolution function of the four-reflection monochromator: a route to a higher intensity

Abstract

The relative intensity passed by a four-reflection monochromator as a function of horizontal and vertical divergence and wavelength is calculated. From this three-dimensional function, the horizontal and vertical divergences, the wavelength band pass and the relative intensity of the monochromator in different settings are calculated. The information is used to design a high-intensity four-reflection monochromator, which is used for applications that require extra intensity. The current design has a 3.8 times higher intensity than the original design but a factor of 15 can be reached without serious redesign of the monochromator. A simple method of calculating rocking-curve peak widths of samples from the monochromator parameters is presented.

Performance of multi-crystal Bragg X-ray spectrometers under the influence of angular misalignments

“…Only at this point did Bartels [5] make and test a four-crystal Ge monochromator with the Ka 1 line of a Cu tube. Since Bartels' work, however, considerable further development has taken place, with a view to improving the energy resolution and the flux collection with different choices of material (Si or Ge) and reflection asymmetries [6][7][8][9].…”