Charge transfer and Penning ionization of N2, CO, CO2, and H2S in proton excited helium mixtures

In this work we report on studies of the kinetics of He–N2 mixtures excited by a proton beam. The rate of charge transfer from both atomic and molecular helium ions to N2 was studied using a time-resolved technique to measure the fluorescence of N+2(B 2Σ+u→X 2Σg). The population of N+2(B2Σ+u) through a Penning ionization process from metastable helium atoms or molecules is observed, and the Penning ionization and charge transfer process which populates this state in a He–N2 laser is discussed. The charge transfer rate constants of He+–CO, He+–CO2, He+–H2S, and He+2–CO are also measured.