A compact point focusing spatial filter for x-ray fluorescence and inelastic x-ray scattering studies

Appropriately selected absorbers combined with spatial filters are frequently used as x-ray low-pass filters in inelastic x-ray scattering studies and x-ray fluorescence spectroscopies. We describe here a compact point focusing spatial filter with a large collection solid angle and excellent rejection of fluorescence from an absorber when used as an x-ray low pass filter. We expect this instrument to have regular application in x-ray microscopies where momentum resolution is irrelevant, such as x-ray fluorescence holography or fluorescence-mode x-ray absorption fine structure measurements using micro-focused beams. As an additional application, we demonstrate that the filter can also be used as the key component in a filter-based analyzer capable of measuring the near edge structure in non-resonant x-ray Raman scattering with 3.0 eV energy resolution. (C) 2001 American Institute of Physics.