The scattering suppression of X‐rays with energy of 20–200 keV in spectrometers with Barkla polarizers

Abstract

The method is proposed for estimating the polarization parameters and the scattering suppression coefficients in energy dispersive X‐ray spectrometers with Barkla polarizers (EDPXRS) for X‐ray fluorescence (XRF) analysis. The scatter suppression coefficients are estimated accounting primary beam polarization, secondary beams yields, detectors response function, and partial factors. Estimations of scatter suppression coefficients due to polarization do not require the use of Stokes parameters and matrices. The method gives the possibility to make polarization‐related corrections in calculations by XRF theory based on scattering cross sections of unpolarized beams. Calculations clarify early estimations of EDPXRS parameters with Barkla polarizers in the 20–200 keV range. The polarizing ability at δ = 7° deviations varies from 0.973 at 20 keV to 0.863 at 200 keV. The analyzing ability of registration system is about the same. In a simple XRF version on a synchrotron radiation with Barkla polarizer, the scattering can be decreased 60 times at 20 keV and 11 times at 80 keV with δs = 3°. In EDPXRS, the scatter suppression factor varies within 10–4.2 at deviations δ = 10° and within 20–4.8 at δ = 7°. The scatter suppression at low energies is determined by angular factor and background and at high energies is limited by energetic factors.

The influence of polarization and filtration of beams on the ED spectrometers sensitivity

“…The scattering cross sections for polarized beams are discussed in Zhalsaraev. [6,7] Thus, due-to-polarization background reduction is estimated in rather complicated ways, while filters background attenuation is estimated very simply.…”

Polarization and intensity of Compton scattering

“…In 1991 Robertson 8 already submitted a patent of using 115 keV Bremsstrahlung polarized X‐rays in order to analyze up to uranium elements in ore by high energy K line XRF. Zhalsaraev 9 evaluated the effects of polarized X‐rays for the sensitivity and detection limits of wavelength‐dispersive 10 and energy‐dispersive 11 XRF spectrometers.…”