Diagnostics of plasmas by CARS (coherent anti- Stokes Raman scattering)

Abstract- Some of the most representative results of the coherent anti-Stokes Raman spectroscopy research program on discharges a t ONERA are presented. A very short review of the principles of CARS and of the main instrumental characteristics is first given. The results of an analysis of a magnetic multipole-confined H, discharge are then shown. The kinetics of rotational and vibrational state populations have been followed in the transient regime and the deactivation of the vibrational level v = 1 by the walls measured. Also, 0, in a glow discharge and in a waveguide discharge has been studied. Rotational, vibrational temperatures and the density of the 'A state have been monitored as functions of position, pressure and discharge current