Evaluation of accurate uncertainty of measurement of L subshell ionization cross-sections

Abstract

Experimentally, X-ray production cross-sections are measured, but ionization cross-sections are calculated theoretically. The uncertainty of the measured L X-ray production cross-section is mainly statistics and detector-efficiency driven. But the experimental ionization cross-section involves many other factors because the relationship between the production and ionization cross section involves various atomic parameters and thus its uncertainty equation is complex. Consequently, determining the measurement uncertainty in L subshell ionization cross-section is always difficult. We have studied this issue in the simplest way, where the rule of weighted propagation of relative uncertainty is utilized. We notice that larger uncertainties are involved in atomic parameters relevant to L1 (2s1/2) subshell than those associated with the other two L2 (2p1/2) and L3 (2p3/2) subshells. Hence, comparison between theory and experiment would give higher emphasis on L2 and L3 subshell ionization cross sections. We believe this work makes us aware that the appropriate uncertainty evaluation is extremely important for providing the right judgement on the data.