Rotational relaxation rate constants for CO2

Abstract

Rotational relaxation rate constants, krot, have been measured for the CO2 00°1 level in three kinds of amplifiers: one using CO2 alone and two others using mixtures of CO2–He and CO2–N2. The experiment consists of perturbing the CO2 00°1 level with a ∼2-nsec saturating pulse at P(20) in the 10.4-μ band and monitoring the subsequent repopulation of the J = 19 rotational state with a probe beam set at P(20) in the 9.4-μ band. The determined rate constants are kCO2–CO2 = 1.3±0.2, kCO2–He = 0.6±0.1, and kCO2–N2 = 1.2±0.2, all in units of 107 sec−1 Torr−1.