Dynamic target screening for two-active-electron classical-trajectory Monte Carlo calculations for H++He collisions

Total cross sections and doubly differential probabilities for various two-electron processes resulting from protons colliding with helium are calculated using a new two-active-electron classical-trajectory Monte Carlo theory in which one electron moves under the influence of the projectile and target nucleus potentials as well as a time-varying potential due to the other electron. This results in a dynamic screening of the target nucleus by one active electron as seen by the other active electron. The results of calculations for the two-electron processes of ionization (including single and double), transfer ionization, ionization, and excitation, as well as double ionization, are presented. The double-ionization results are compared with recent experimental results and are found to have an improved agreement over any other results available to date