Vibrational state distributions of H+2(v″) resulting from the electron transfer reactions H+2(v′=0, 1) +H2(v″=0)→H2(v′)+H+2(v″) in the collisional energy range of 2–16 eV

Abstract

The vibrational state distributions of product H+2(v″) resulting from the symmetric charge transfer reactions H+2(v′0=0 or 1) +H2(v″0=0) →H2(v′) +H+2(v″) in the center-of-mass collisional energy (Ec.m.) range of 2–16 eV have been measured by the charge exchange method. When reactant H+2 ions are prepared in v′0 =0, the majority (>80%) of product H+2 ions are formed in v″=0. The vibrational relaxation channel for forming H+2(v″=0) is found to be much more efficient than the vibrational excitation process for producing H+2(v″=2) in the H+2(v0=1) +H2(v″0=0) charge transfer collisions. The experiment also reveals that inelastic charge transfer channels become more important as Ec.m. is increased. The vibrational state distributions of product H+2(v″) determined at Ec.m. =8 and 16 eV are compared with results of the semiclassical energy conserving trajectory calculations of Lee and DePristo. A better agreement between experimental and theoretical results is observed at Ec.m. =16 eV, a collisional energy at which charge transfer is the overwhelming channel.