Measurement of vibrational, gas, and rotational temperatures of H-2 (X-1 Sigma(+)(g)) in radio frequency inductive discharge plasma by multiplex coherent anti-Stokes Raman scattering spectroscopy technique

Translational, rotational, and vibrational temperatures of H2 in radio frequency inductive discharge plasmas at pressures and power release ranges, respectively, of 0.5-8 torr and 0.5-2 W/cm3 have been measured by using multiplex coherent anti-Stokes Raman scattering ?CARS? spectroscopy. Computational codes have been developed to determine the rotational and vibrational temperatures and to analyze H2 CARS spectrum for nonequilibrium conditions. The results show a decrease of the vibrational temperature from 4250 to 2800 K by increasing the pressure from 0.5 to 8 torr and a corresponding increase of the rotational temperature from 525 to 750 K.