Thomson Scattering Applied to a Noisy Radiative Plasma

Thomson scattering with a 1.5 ms long pulse mode 20 J ruby laser has been applied to a radiative argon plasma with electron densities n_e from 2.5 10¹⁹ m^?3 to 1.5 10²⁰ m^?3 and an electron temperature T_e of about 3 eV. Photon counting techniques have been used. The accuracy of n_e and T_e to be reached is about 5% after 10 shots. The signal to noise ratio S/N has been optimized by the use of optical filters and a special purpose grating. The effects of these elements on S/N have been calculated. The entrance angle, transmission and quantum efficiency have also been optimized. A comparison between 5 possible laser systems, including a normal mode and a Q-switched mode ruby laser, has been carried out.