Analysis of energy transfer for thermally available vibrational energy levels as measured by photoacoustic and infrared emission techniques

Abstract

An account is given of the analysis of energy relaxation processes for thermally available vibrational energy levels as measured by photoacoustic and infrared emission experiments employing intensity-modulation of the incident radiation. The main aim is to establish the effect on the observables of the distribution of the initially absorbed energy amongst the available energy modes, i.e., to examine the role of translational heating. A technique using the vibrational temperatures involved is set up for the two-level problem, and developed in some detail for the more complex multi-level situation. The formulae obtained are directly related to experimental results, and should be useful to experimentalists working, in particular, with spectrophone measurements.