Khz rate simultaneous rotational and vibrational thermometry in a nonequilibrium plasma using hybrid fs/ps-CARS

Abstract

Hybrid femto/picosecond coherent anti-Stokes Raman scattering (fs/ps-CARS) spectroscopy has been used to perform 1 kHz single-shot thermometry in a low-pressure nonequilibrium N2 DC glow discharge, where the rotational and vibrational temperatures differ significantly. Q-branch Raman spectra of N2 are used to simultaneously retrieve vibrational temperatures up to 4000 K and rotational temperatures up to 1000 K with better than 10% precision. The single shot and high-repetition rate capabilities of the fs/ps-CARS technique permit observations of transient dynamics both during and after the discharge.