Measurements of Electron Temperature and Density of Slow Theta Pinch Plasma by Laser Scattering

Abstract

Laser scattering is a very powerfull diagnostic technique for the measurements of high temperature and high density plasmas. This method has been used in many experiments with successfull results. Here 90° scattering is observed to determine the electron temperature and density of the slow theta pinch plasma of relatively large device, which had. been used as a plasma source of BSG devices. The temperature and density are in the order of-1016cM-3and_??_10 eV, respectively, so that the plasma is isothermal (τie<10-6sec), and then ion temperature, which ia more important for the experiment, can be estmated as well as electron temperature and density. The characteristics of theta pinch are : L=60 cm, d=10 cm, V=40 kV and E=ll kJ. The results of scattering theory are simply descrimbed for the understanding of experimental results. Observed scattered spectra were ranged from α=0.3 to 1.3 and electron temperature, from about 8 to 4 eV, according to experimental conditions. The time dependence of electron temperature and density was obtained in case of initial gas pressure.of 35 mtorr.