M-shell X-ray production cross sections for PIXE applications

M-shell X-ray production cross sections by protons of energies 0.1-4.0 MeV are reported for the most intense M-alpha beta(M4.5N6.7), M-7(M3N4.5) and M 3O4.5 M-X ray transitions appearing in PIXE spectra. The cross sections hav e been measured systematically for selected heavy elements between Ta and T h (Z(2) = 73-90). Measured M-X-ray production cross sections were found to be universal with respect of M-shell scaled velocity xi(M). The data are co mpared with available theoretical calculations of M-shell ionization by cha rged particles based on the plane-wave Born approximation (PWBA) and the se miclassical approximation (SCA), as well as the ECPSSR theory and relativis tic RPWBA-BC which are going beyond the first order treatment. Simple param eterization of experimental proton induced M-X-ray cross sections is propos ed for PIXE applications. This parameterization, being accurate within +/-5 %, can be used for precise determination of heavy metal concentrations by P IXE technique. (C) 1999 Elsevier Science B.V. All rights reserved.