Chemi-ionization and secondary ion reactions in molecular hydrogen and its isotopes on impact of metastable helium atoms

Publisher Website
Google Scholar
Abstract
Relative cross sections for the following reactions are reported: in which X2 is (a) H2, (b) D2, and (c) HD. The isotope effect in the production of HeH+ and HeD+ in Reaction (2c) was determined and relative measurements were made of the kinetic energy of the ion product in Reaction (1). The cross section for the secondary reaction was also determined as a function of the relative kinetic energy of the reactants. This energy‐dependent cross section was determined for H2+ formed both by helium metastable atom collisions and by electron impact. The cross section for H+2 formed by metastable helium was found to be greater than for H+2 formed by electron impact. This may be evidence for an additional reaction producing H+3 involving highly excited Rydberg states of H2 as reactants.