Chemiionization of Excited Mercury Atom with 253.7 nm Irradiation in the Presence of N2 and CH4

Abstract

Abstract Chemiionization of excited mercury atom with 253.7 nm irradiation was studied. Results on the system Hg–N2 previously reported were further confirmed. It was found that CH4 can also induce chemiionization of Hg atoms with 253.7 nm irradiation. The dependence of ionization current on CH4 pressure and light intensity was investigated, the ionization current being found to be proportional to the square of light intensity and to increase with increase in CH4 pressure up to 30 Torr, reaching a constant value. N2 and CH4 are considered to show a similar behavior in ionization current against pressure and light intensity, and other substances such as H2, He, CO, NO, Ar, C2H4, and 1-butene to give no appreciable ionization current. Thus the mechanism in which chemiionization proceeds through the collision of Hg(3P1) with Hg(3P0) is further confirmed.