L-subshell x-ray cross sections for proton collisions with Pt, Au, and Hg. [Ionization, binding energy, coulomb-deflection]

The L x-ray production cross sections for the L..cap alpha../sub 1//sub ,//sub 2/, L..gamma../sub 1//sub ,//sub 5/, and L..gamma../sub 2//sub ,//sub 3//sub ,//sub 6/ transitions in Pt, Au, and Hg have been measured by ionization of the L-subshell electrons with 0.4--2.0-MeV proton bombardment. Individual subshell ionization cross sections, sigma/sub L/i-italic (i = 1, 2, or 3), have been extracted from the x-ray yields. Comparisons of the x-ray production and ionization cross-section data have been made with the predictions of the plane-wave Born approximation (PWBA), the PWBA with binding-energy and/or Coulomb-deflection effects, and the constrained binary-encounter approximation (CBEA). The binding-energy and Coulomb-deflection effects partially account for the gross quantitative discrepancies between the PWBA and the data for proton energies less than 1 MeV. Substantial discrepancy still exists, as evidenced by the disagreement between the data for sigma/sub L/3/sigma/sub L/2 and all the theoretical predictions. (AIP)