Microwave technique for measuring vibrational temperature in pulsed nitrogen discharges

A microwave radiometric technique has been developed to measure the molecular vibrational temperature in the active period of a pulsed N2 discharge. The technique monitors decay of the electron average energy Ūe in the afterglow. Kinetic theory analysis shows that if the quasi-steady-state value of Ūe > 0.5 eV, it may be taken as a direct measure of the vibrational temperature Tv in the active period. For lower values of average energy, elastic and rotational energy losses must be included in the calculation of Tv. The results are the first experimental confirmation of the electron-molecular coupling proposed by Hurle.