Determination of the kinetic coefficients of a gas in a supersonic jet from Brillouin spontaneous scattering spectra

The mean free path and the shear viscosity of molecular nitrogen are determined in a rarefied supersonic jet using the Brillouin spontaneous scattering technique. By examples of sub- and supersonic jets, the measured kinetic coefficients are shown to agree with the tabulated values of these parameters. These results are obtained using laser radiation, whose output power, which restricts the signal-to-noise ratio, is as low as 50 mW.