Measurement of the relative proton-induced L-subshell ionization cross sections of Ag, Sb and Au

L X-rays were produced by the impact of protons between 200 and 900 keV energy on thin Ag, Sb and Au foils. The spectra were measured by a Si(Li) detector and analysed by least-squares techniques to yield X-ray intensity ratios as a function of energy. From these, ionization cross section ratios for the subshells L I , L II and L III were calculated. For Ag and Sb, X-ray emission rate ratios were also determined which agree with Scofield's values in many cases, but not in all. For Au, X-ray intensity ratios are generally in agreement with published results; for Ag and Sb, the ratio L alpha /Ll is smaller than Scofield's values. The ratio sigma 2 / sigma 1 is generally well described by the plane-wave Born approximation theory; for the ratio sigma 3 / sigma 2 , a decision between different theories is difficult.