Band-reject-filtering X-ray spectra by mosaic structures of pyrolytic graphite

The possibility of effective band-reject filtration of intense spectral lines in X-ray spectra and the creation of deep spectral valleys in the continuous spectrum by diffraction extinction was shown. Optimum material for band-reject filters in the energy range E > 6 keV is highly oriented pyrolytic graphite (HOPG). The filtering scheme in the form of an echelon arrangement of HOPG films is proposed, which suppresses the negative effect of multiple reflections due to diffraction extinction. The full width at half minimum of the spectral valleys can vary from tens of electronvolt to several kiloelectron volt depending on the HOPG mosaic spread, HOPG filters arrangement, and rejected energy region. At the energy range E of 10 keV, the spectral density attenuation value may be of order 10(-3) and lower. The obtained results can be used in various fields of X-ray spectrometry, as well as in static energy dispersive diffractometry and reflectometry.