Experimental investigation of the ionization dynamics in slow p-H2 collisions

The single ionization (SI) and the transfer ionization (TI) of H2 have been investigated utilizing the Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) reaction microscope. Continuum electron velocity spectra have been measured for experimentally determined nuclear motion. Electron velocity distributions for the SI of H2 show that the ejected electrons lie mainly in the scattering plane where their velocities were found to lie between those of the recoiling target and the scattered projectile. In addition to a group of electrons seen in SI saddle electrons group, the electron velocity spectra for TI of H2 unveiled the existence of another group of electrons with different structure. These electrons were emitted with velocities greater than the projectile velocity and found to result from a narrow range of impact parameters. These fast forward electrons reveal a substantial amount of out-of-plane scattering.