Angular dependence of L x-ray production cross sections in seven elements from Yb to Pt at a photon energy of 59.5 keV

The L-l, L-alpha, L-beta and L-gamma x-ray production cross sections of Pt, Re, W,Ta, Hf,Lu and Yb have been measured using an incident photon energy of 59.5 keV at an angular range of 40-130 degrees. The measurements were pe rformed using a Am-241 radioisotope as the photon source and a detection sy stem with a Si(Li) detector. Although differential cross sections for Lg an d L, x-rays were found to be angle independent within experimental error, t hose for the La and L, x-rays were found to be angle dependent. As previous ly reported this confirms the angular dependence of photon-induced La and L , x-ray production cross sections. Furthermore the present results also con firm the theoretical predictions of Flugge er al (Flugge S, Melhorn W and S chmidt V 1972 Phys. Rev. Lett. 29 7) and Jacobs (Jacobs V L 1972 J. Phys. B : At. Mel. Phys. 5 2257). However, our experimental results are contrary to the results reported by Mehta et al (Mehta D, Purl S, Singh N, Garg M L an d Trehan P N 1999 Phys. Rev. A 59 2723). Integral cross sections for the pr oduction of L-l, L-alpha, L-beta and L-gamma x-rays are also deduced in thi s paper and are found to be in good agreement with theoretical values.