Time resolved Thomson scattering measurements of the electron and ion temperatures in a high intensity laser–plasma interaction

Abstract
Time resolved Thomson scattering from thermal plasma fluctuations is used to measure the electron and ion temperatures in the interaction of a short pulse (1 nsec FWHM), high intensity (∼2×1014 W/cm2) CO2 laser beam with a preformed carbon plasma. Time histories of the plasma temperatures with a temporal resolution of ∼150 psec were obtained in a single irradiation/discharge event by streaking the Thomson scattering spectrum. The experimentally measured electron temperature was found to be lower than that predicted by computer simulations. The discrepancy is attributed mainly to a decrease in the inverse bremsstrahlung absorption coefficient at high laser intensities (vosc/ve>1) .