Vibrational energy relaxation of highly compressed N2–D2 mixtures

Abstract

Vibrational energy relaxation time T1 of nitrogen in highly compressed mixtures of D2–N2 has been measured at room temperature as a function of gas density and mixture ratio. The first vibrational state of N2 has been populated by a rapid V–V transfer from D2 which has been vibrationally excited by collision-induced absorption. The decay of the N2 vibrational excited population has been time resolved by monitoring the infrared collision-induced fluorescence. The data are compared with attractive hard-sphere models developed for energy relaxation in dense fluids.