F.J. Himpsel, H. Akatsu, et al.
Progress in Surface Science
A low pass filter is described that suppresses higher-order diffraction light from vacuum ultraviolet and soft x-ray monochromators. It consists of a triple silicon reflector with the angle of incidence matched to the desired photon energy cutoff. The performance is calculated and tested experimentally using a toroidal grating monochromator.