Yields ofKandLX Rays Arising from 2-30-MeV-Proton Bombardment of Ag

Abstract

Ag $K$ and $L$ x-ray yields have been measured for 2-30-MeV protons incident on a thin Ag foil target with a Si(Li) x-ray detector (resolution 540 eV at 6 keV). The absolute $K$-shell ionization cross section ${\sigma }_K$ extracted from these measurements has been compared to plane-wave-Born-approximation (PWBA) and binary-encounter-approximation (BEA) calculations and agrees quite well with both over the energy range covered in this investigation. However, the PWBA and BEA predictions of $L$-shell ionization cross sections are low by a factor close to 2 compared to experimental values for ${\sigma }_L$, although both predict an energy dependence for the shape of ${\sigma }_L$ in good agreement with that observed. The disagreement in magnitude is most likely because of the present inadequate $L$-shell fluorescence yields for medium-and low-$Z$ atoms. The $\frac{K\alpha }{K\beta }$ x-ray intensity ratio for proton bombardment of Ag from 2-30 MeV was observed to be constant (4.68±0.33) and consistently slightly below Scofield's calculation (5.09). The unresolved $K\beta$ peak was decomposed into its two major components $K{\beta }_{1,3}$ and $K{\beta }_2$ whose ratio appeared to be weakly dependent on proton-beam energy.