Measurement of the electron temperature and density of a helium plasma produced by a hollow cathode arc discharge

The electron temperature and electron density of a steady state helium plasma produced by a hollow cathode arc discharge have been measured with the aid of Thomson scattering as functions of the radial distance to the plasma axis. Electron densities in the range of 1 x 1019 to 4 x 1019m-3 and electron temperatures 0.5 x 105 to 2.5 x 105 K were determined with an accuracy of 5% in both. The observed Thomson spectra indicate a Maxwell-Boltzmann velocity distribution of the electrons. The Thomson scattering measurements have been spatially extended by probe measurements. (author)