BOLTZMANNPOPULATION, EXCITATION TEMPERATURE AND EXCITATION OF MATERIAL LINES IN A HIGH-CURRENT HOLLOW CATHODE

Measurements of relative intensities of Fe I spectral lines in the negative glow of a high-current hollow cathode show that at low discharge currents and low gas pressures there is no Boltzmann distribution. With increasing discharge current and gas pressure, however, this condition is approached. By means of cathode sputtering experiments and measurements of relative intensities it could be shown that material lines are excited by collisions of the second kind. Excitation temperatures are also measured and discussed. © 1969 Springer-Verlag.