Total cross-section calculations on proton-impact ionization of hydrogen

We have calculated the total cross section for proton-impact ionization of atomic hydrogen for the intermediate energy range 25-100 keV. We evaluate error bars of 5% on our theoretical values. The present results disagree with the experiment of Shah and Gilbody [J. Phys. B 14, 2361 (1981)] and Shah et at. [J. Phys. B 20, 2481 (1987)], differing by 20% at the peak of the ionization cross section. On the other hand, our results show better agreement with two recent theoretical calculations, one performed by close coupling and the other by integrating the time-dependent Schrodinger equation on a three-dimensional lattice. The present results also compare favorably with theoretical and experimental determinations of capture and excitation cross sections. We describe the two-center momentum space discretization method, used here, in detail, explaining how the cross sections and corresponding error bars are determined.