Relative Cross Sections for the Intramultiplet Quenching of Hg(63P2) to Hg(63P1)

Relative intramultiplet quenching cross sections for the transition $\mathrm{Hg}{\text{(6}}^3{P}_2\mathrm{)\to }\mathrm{Hg}{\text{(6}}^3{P}_1)$ have been obtained for a variety of collision partners by using crossed molecular beams and monitoring the phosphorescence of Hg(6³P₁) from the cross beam interaction region. Energy resonance with vibrational states does not appear to be a major factor in determining the magnitude of the intramultiplet cross sections for this process. The results with He and Xe indicate that internal degrees of freedom are required for significant cross sections when the quencher lacks excited electronic states below Hg(6³P₂). In general the large differences in cross sections observed with molecules are best explained in terms of competitive processes, e.g., highly reactive molecules tend to have small intramultiplet cross sections. The present data are compared with total and intramultiplet cross sections for Hg(6³P₁) which have been obtained by optical excitation in bulb experiments.