Determination of the rotational temperature of UF6 and pressure in a supersonic expansion by use of the Q branch under the influence of pressure broadening

A spectroscopic method is proposed for the simultaneous determination of both the rotational temperature of UF6 diluted with Ar and the total pressure in a supersonic Laval nozzle expansion. This method utilizes the fact that the relative intensities of the sub-bands of a Q branch depend on the rotational temperature and pressure. The values determined for the rotational temperature were found to agree with the temperature calculated on the assumption of thermal equilibrium under isentropic expansion. The total pressures estimated from the Q branch agree with the ones measured with a capacitance manometer.