Investigation of the vibrational temperature kinetics in a TEA CO$_2$ laser

Detailed experimental investigations of the kinetics of the vibrational and translational temperatures of the active medium of a TEA CO$_2$ laser are reported for the first time. A comparison of the theoretical and experimental results confirms the validity of the generally adopted temperature model for times $\gtrsim1$ $\mu$sec/atm after the start of the discharge. A considerable difference between the experimental and theoretical results in the range $<1\mu$sec/atm shows that in this range a dynamic equilibrium is still absent between the lower levels of the symmetric and bending modes. A reduction discovered in the rate of transfer of vibrational energy from N$_2$ to CO$_2$ for excitation in an electric discharge is explained by the excitation of the higher vibrational levels of N$_2$, a low $VV$ relaxation rate in nitrogen, and anharmonicity of the N$_2$ molecule.