Vibrational excitation in proton-hydrogen collisions at medium energies

Abstract

The vibrational populations of H,(X 'Xi, 0) produced by Hf projectiles at energies 90s E s IOOOeV have been measured as a function of the scattering angle 9. A strang vibrational excitation is observed at large angler far all energies studied. Measurements of charge exchange and electronic excitation have also been performed in order to examine whether this vibrational excitation may be related to these processes. A relative increase o i the charge tranrier dirierentiai cross section is thus observed when the coilision energy increases. A simple model is tried to rationalize the variations with E and 8 of the vibrational excitation. A fairly good agreement between the experimental and theoretical results is obtained especially at low energy. The discrepancies found at higher energy may be explained in terms of interactions neglected in the model such as charge transfer and electronic excitation.