Formation of the background component of the analytical signal in the long-wavelength region of X-ray fluorescence spectrum

Components of X-ray background in the long-wavelength spectral region of a crystal diffraction X-ray fluorescence spectrometer were calculated. The calculations took into account the bremsstrahlung radiation of free electrons, diffuse scattering and fluorescence of the crystal analyzer, and high-order reflections of the scattered radiation of the fluorescent sample by the crystal analyzer. The results of calculations were compared with the intensities of background samples measured in the region of the Na K α fluorescence line on an SRM-25 wave X-ray spectrometer. The experimental background intensities (response function) well correlate with those found by the regression equation with calculated factors. The importance of particular processes in the formation of X-ray background was assessed.