A BOXCARS investigation of the V–V energy transfer from highly excited SF6 to CS2 and the sensitized photodissociation of CS2

Abstract

The BOXCARS technique was used to investigate the vibrational energy transfer between highly excited SF6 and CS2, and for the sensitized photodissociation of CS2. The analysis of data, as reported in our previous studies, to extract vibrational temperature from the CARS signal has been revised in the present work to adjust for the fact that the ground-state population may not be constant. The current investigation suggests that IR laser excitation of SF6 and the energy exchange between excited SF6 and CS2 create a high-lying vibrational energy reservoir in the CS2 vibrational manifold. The rate of energy transfer depends on the partial pressures of SF6 and CS2, and the excitation intensity. The transfer rate shows greater dependence on the partial pressure of SF6 than on the partial pressure of CS2. At higher excitation energies, the energy reservoir leads to photofragmentation products.