Electron temperature and density profiles in a neutral loop discharge plasma

Thomson scattering measurements of electron temperature and density in a neutral loop discharge (NLD) plasma were performed in order to reveal electron behavior around the neutral loop. The method yielded unambiguous and reliable results, enabling quantitative analyses of particle balance to be made. The results showed that the electron temperature had a peak on the neutral loop and, in contrast, the electron density had a peak at a position radially inward from the neutral loop. We suggest that charged particles are produced by electron impact ionization of argon atoms on the neutral loop and then flow radially inward. The effect of the magnetic field strength on the NLD plasma formation is also discussed.