Energy Transfer between Molecules and Electronically Excited Atoms

The technique of competitive quenching has been used to determine the relative rate constants of O2, N2, H2, CO2, and CH4 for quenching of excited argon atoms formed both by the action of β radiation from a tritium source and also by low-energy electron impact. Calculations based on the mean lifetime of these species in the system show that with the exception of nitrogen the quenching process for all the other molecules is highly efficient and energy transfer occurs on every collision. Evidence is also presented to suggest that the excited species formed by collision with β rays are primarily in the 1P1 state and not the 3P0,2 metastable states.