Formation of anions and cations via a binary-encounter process in OH${}^{+}$ + Ar collisions: the role of dissociative excitation and statistical aspects

Abstract

Molecular fragmentation leading to the formation of negatively and positively charged hydrogen ions in 7-keV OH${}^{+}$ + Ar collisions is investigated experimentally. The most striking finding is that negative and positive hydrogen ions are emitted with very similar angular dependences. Also, the kinetic energy distribution of the H${}^{+}$ fragment shows strong similarities with that of the ejected H${}^{-}$ ion. The kinematics of the emitted H core is found to be essentially driven by its scattering on the atomic target. However, in addition to this binary-encounter process, dissociative electronic excitation of the molecular projectile has to be invoked to explain the observed fragmentation patterns. Though the electron capture process is complex, it is shown that the relative population of the different final charge states of the outgoing fragments can be described by simple statistical laws.

References in corpus (1)

• Formation of negative hydrogen ions in 7-keV OH+ + Ar and OH+ + acetone collisions: a general process for H-bearing molecular species

Cited by in corpus (4)

• Anion emission from water molecules colliding with positive ions: Identification of binary and many-body processes
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• Thermodynamic model for electron emission and negative- and positive-ion formation in keV molecular collisions
• Anion and cation emission from water molecules after collisions with 6.6-keV ${}^{16}$O${}^{+}$ ions