Postcollisional decay in Ne multiple ionization by H2+ ions in breakup collisions

Abstract

We measured the Neq+ charge-state yield distribution for Ne atoms multiply ionized by 1-MeV/amu H2+, in coincidence with the final state of the projectile, for both breakup and nonbreakup channels. Measurements with 1-MeV H+ projectiles were also performed. While the H2+ nonbreakup channel produces results similar to equal-velocity proton or electron projectiles, the breakup channels lead to a charge-state yield distribution very close to the known Ne 2s-1 postcollisional decay distribution, measured through photoionization [T. A. Carlson, W. E. Hunt, and M. O. Krause, Phys. Rev. 151, 41 (1966)]. This behavior suggests that, in the breakup channels, contributions to multiple ionization from mechanisms that are usually considered to be dominant in ion-atom collisions are less important than the postcollisional decay.