A CROSSED BEAM STUDY OF THE IONIZATION OF MOLECULES BY METASTABLE NEON ATOMS

Total ionization cross sections for the collisions between metastable Ne*(3P2,0) atoms (predominantly 3P2) and several molecules (N2, CO, O2, NO, HCl, HBr, Cl2, CO2, N2O, CH4, CH3Cl, CH3Br, C2H6, C2H4, and C2H2) have been measured, in a crossed beam experiment, within the ≈ 0.03 to ≈ 0.5 eV collision energy range. The cross sections have been obtained on the same relative scale for all systems and calibrated to an absolute value by assuming a literature value for the reference system Ne*-Ar. These experimental cross sections have been integrated over the Maxwell-Boltzmann distribution to estimate the values of the ionizationrate constants. Comparison between the ionization and the quenching rate constants shows that the ionization is the main channel for the quenching of metastable neon atoms in thermal systems. © 1990.