On the V ‐ I Characteristic of the Double‐Cathode Discharge in a Longitudinal Magnetic Field

Abstract

The V -I characteristics of a double-cathode discharge with plane-parallel cathodes in Ne are investigated. It is shown that the differential resistance -, as a function of the tube voltage, reaches a minimum value which can be zero or negative in a given range of pressures and magnetic field intensities. The departure of the differential resistance plot from the typical pattern for a usual abnormal discharge can characterize the degree of development of the hollow cathode effect in the plane parallel geometry and shows the influence of the longitudinal magnetic field. dV d IPrevious works [l-121 dedicated to the experimental study of the negative glow plasma from a double cathode cold discharge immersed in a longitudinal magnetic field showed that for certain correlated values of cathode spacing, pressure, and magnetic field a considerable increase of the discharge current and radiation intensity occurs, at a practically constant voltage. The phenomenon was interpreted as a particular form of beam-plasma interaction, the two oppot Fig.1. The discharge device. A = anode, C = water cooled cathodes