Measurement of L X-ray production cross sections by impact of proton beams on Hf, Ir, and Tl

•A new data set of L X-ray production cross sections by proton impact is given.•The incident energy range for elements 72Hf, 77Ir, and 81Tl extends up to 4.75 MeV.•The ECPSSR theory is used, with United Atom and Multiple Ionization corrections.•Intra-shell coupling is also considered.•Definite conclusions about theories are complicated by experimental uncertainties.

In spite of the existence of a large quantity of experimental results for X-ray production cross sections by proton beam impact, recent publications emphasize the need for more measurements in several targets and energy ranges. Following these recommendations, this work presents results with some heavy elements (72Hf, 77Ir, and 81Tl) irradiated with protons in the energy interval 0.45 MeV–4.75 MeV. The results are compared with experimental data from previous publications, empirical tables, as well as with predictions of the ECPSSR theory with the United Atom modification, intra-shell coupling corrections, and Multiple Ionization effects. Although there is good coincidence with previous experiments, the agreement among the theories with the experimental data does not allow a definitive conclusion about the best predictions for the measured cross sections.