Plasma Potential Fluctuations in a Reflex Discharge with Thermionic Cathode

One of the promising applications of low-temperature plasma in crossed electric and magnetic fields is plasma mass separation. To its implementation it is necessary to create a magnetized plasma with a given spatial distribution of the plasma potential. Plasma potential distribution determines the particle trajectories during separation. One of the difficulties that lie in the way of creating an efficient separator is the oscillations of the plasma potential resulting from the development of various types of instabilities. In the present work, fluctuations of the plasma potential in a reflex discharge with a thermionic cathode are studied. An analysis of the frequencies of plasma potential oscillations for magnetic fields in the range of 1-1.4 kG is presented. Measurements of the radial profiles of the root-mean-square deviation of the plasma potential are provided.