Desorption of H- ions from solid surfaces induced by MeV ion impact

A model for desorption of H- ions from solid surfaces induced by MeV ion impact is proposed. The desorption process is considered as a result of transition to an antibonding state caused by collision with secondary electrons escaping the ion track. The H- yield has been calculated taking into account the effect of the ion track potential. The yield was shown to change dramatically with primary ion angle of incidence: depending on film thickness: opposite tendencies in variation of the yield with the angle of incidence are revealed in agreement with experiment. The energy and angular distributions of the emitted H- ions have also been calculated and compared with experimental data. (orig.)