Quenching of excited mercury atoms (6 3P 1 and 6 3P 0) in collisions with SiH 4, SiD 4, Si 2H 6 and GeH 4

Abstract

The cross sections for Hg(6 3P 1) and Hg(6 3P 0) quenching by SiH 4, SiD 4, Si 2H 6 and GeH 4 have been obtained from steady-state experiments of Hg photosensitization at 253.7 nm. The quenching rate of Hg(6 3P 1) was determined from the decrease of the 253.7 nm fluorescence intensity as a function of pressure of the quenching gas, and the effect of radiation imprisonment was taken into account. Metastable Hg(6 3P 0) atoms were produced by photosensitization of NH 3 and their quenching rate was derived from the attenuation of partial pressure of the added quenching gas. Both methods were tested with H 2 and C 2H 4 giving results in good agreement with those reported in the literature. The series of silane molecules, as well as germane, appear as excellent quenchers of both Hg(6 3P 1) and Hg(6 3P 0) at nearly collisional rates in contrast with the first members of the alkane series.