An investigation of the distribution of the intensity of spectral lines in the gap length of a copper dc arc of 7A, burning both with and without nonhomogenous magnetic field, will be described in this paper. The close-electrode intensification effect of spectral lines has been observed and its variation with the time of preliminary burning and the gap length has been investigated. It has been established that close-electrode intensification appears only with the ionic lines. An increase of the intensity of some spectral lines and certain variations in their distribution have been observed when the arc is burning in a magnetic field. The temperature range has been studied in its relationship to the gap length. The temperature around the cathode region is approximately 6500 K and that around the anode region is about 6000 K. The superposition of an external magnetic field contributes to an increase of the temperature of about 400 K. Some possibilities for the application of these effects in the case of spectral analytical determinations have been suggested.
A. Petrakiev and R. Milanova, "An Investigation of Close-Electrode Intensification in a dc Arc in a Magnetic Field," Appl. Spectrosc. 24, 95-98 (1970)