Relative L-shell X-ray emission rates in PIXE

L shell X-ray emission rates usually used as a part of a data base for analysis of PIXE spectra are theoretical values based on Dirac-Hartree-Slater (DHS) [J.H. Scofield, At. Data Nucl. Data Tables 14 (1974) 121] or Dirac-Harbree-Fock (DHF) [J.H. Scofield, Phys. Rev. A 10 (1974) 1507] calculations, or semiempirical data of Salem et al. [At. Data Nucl. Data Tables 14 (1974) 91], obtained from pre-1974 experiments with radioactive sources or sources ionized by photon or electron bombardment. Recently published L-subshell X-ray production cross sections by proton impact have been used to extract relative L-shell X-ray emission rates for some groups of L-shell X-ray lines, in order to compare them with the values from the three data bases mentioned before.