Triply-differential cross sections for electron-impact ionization of atomic hydrogen

A method for obtaining triply-differential cross sections (TDCS) for electron-impact ionization of atomic hydrogen in the Glauber approximation is developed. The expression for the Glauber amplitude in the present case turns out to be a simple two-dimensional integral which can be accurately evaluated. The present procedure has an advantage over the conventional partial-wave technique in calculating TDCS in that the latter requires substantial computer time where many partial waves are involved. We present numerical results for electron-impact ionization of hydrogen atoms at incident energies of 100, 113.6, and 250 eV. A comparison is made of the present TDCS with the corresponding results of the first Born approximation and experiment.