Universal empirical fit to Lα, Lβ and Lγ x-ray production cross section by protons impact within updated experimental data: Three dimensional (Z-dependence), collective and individual formulae

Abstract

The aim of this contribution is to investigate the different empirical procedures to deduce the L lines x-ray production cross sections for a wide range of elements (50≤Z ≤ 92) by proton impact. The data base which relies on different compilations available in the literature, is used from three different aspects, to deduce a new empirical production cross sections of the main x-ray lines Lα, Lβ and Lγ. One, the data are fitted collectively by analytical functions to calculate the empirical cross sections. Second, three dimensional empirical L-shell x-ray production cross sections have been deduced by introducing the dependence of the universal trend of the updated experimental data on the atomic number of the target, noted as “Z-dependence”. Third, these experimental data can be presented in a single curve depending on a scaling law extracted from studies in the most familiar theories of collision (PWBA). Then, a first order exponential decay function was used to fit very well the existing database of the main x-ray lines Lα, Lβ and Lγ cross sections for elements from 50Sn to 90U. Generally, the deduced production cross sections obtained by fitting the available experimental data for each element separately give the most reliable values than those obtained by a global fit. At last, a comparison is made between the three empirical formula reported in this work, those obtained using the ECPSSR model and other earlier works.