Double ionization ofH2by fast bare-ion collisions

Abstract

A time-dependent close-coupling method is developed to treat the double ionization of ${\text{H}}_{2}$ by fast bare-ion collisions. At high incident energies, for which charge transfer to the projectile may be ignored, multipole expansions are made for the electron-electron and electron-projectile interactions in a fixed target nuclei coordinate system. The time-dependent Schr\"odinger equation for the six dimensional target electron wave function is reduced to a set of close-coupled equations on a four dimensional numerical lattice in $({r}_{1},{\ensuremath{\theta}}_{1},{r}_{2},{\ensuremath{\theta}}_{2})$ center-of-mass spherical polar coordinates. Time-dependent close-coupling calculations are carried out for $p+{\text{H}}_{2}$ collisions at an incident energy of 1.0 MeV. The ratio of double to single ionization is found to be 0.3%, which is in reasonable agreement with experimental measurements.