Dependence of the Compton to Rayleigh intensity ratio on the scatterer atomic number in the range of 4(Be) to 31(Ga).

Compton to Rayleigh scattering intensity ratios (IC/IR) have been measured using X‐rays with energy 17.44 keV for single‐component materials with atomic number Z from 4 (Be) to 31 (Ga) and binary compounds of stoichiometric composition. The measurements have been performed using two optical schemes: an energy‐dispersive X‐ray fluorescence scheme with a molybdenum secondary target and wavelength‐dispersive X‐ray fluorescence one. The processing of the spectra was carried out by fitting with Pearson VII functions. For single‐component and binary standards, the experimental dependence of the scattering intensity ratio on the atomic number was found to be the same. This confirms the additivity of the contribution of different atoms to the scattering. The dependence has a complex shape but is well described by the theoretical relationship for IC/IR with correction on the difference between Compton and Rayleigh radiation absorption coefficients. Two ranges of atomic number values are defined, in which the effective atomic number Zeff can be determined by the calibration method using this dependence: for Z from 4 to 7 with low error of ΔZeff =±0.15 and for Zeff from 10 to 18 with low error of ΔZeff =±0.69. A change in the shape of the Compton peak and an overestimated value of the of the Compton and Rayleigh peak intensity ratio when passing from a single‐component scatterer (Al or Si) to their oxides Al2O3 or SiO2, respectively, have been revealed. [ABSTRACT FROM AUTHOR]