A Study of Glow Discharge in a Strong Transverse Magnetic Field

Glow discharges in axial magnetic field have been studied intensively since the 1930s [1-2]. The radial field case has been studied as well [3], but solely for coaxial electrodes placed in a weaker field. In this work, we investigate the gas discharge from cold cathode Geissler tubes in a transverse B-field of about 2T. Though the initial goal was detection and analysis of the Zeeman effect as reported here in a different section [4], we have discovered the formation of a dense plasma layer under specific physical conditions. Interestingly, this layer forms in Ar, but not in other tested noble gases, i.e., Ne, Kr and Xe. At the same time, a weak HeII ion line was detected in a He tube. As the gas becomes ionized, plasma begins to etch the wall material, in this case, AR glass with known chemical composition. The erosion products' emission lines are identified using high-res spectroscopy. Measured broad NUV-NIR spectra are presented as well for different gases and conditions.