Electron density and temperature in the pulsed-orbitron-maser glow discharge

In order to better understand the pulsed-glow discharge that provides the feed electrons for a pulsed-orbitron maser, the authors report using penetrating microwave beams and radially inserted Langmuir probes to make bulk and radial measurements of the number density in the plasma. The Langmuir probe was also used to measure the electron temperature across the plasma radius, and to investigate the effects of an externally applied magnetic field on the RF output of the orbitron. It was found that the emitted frequency is apparently not related to the electron plasma frequency by any simple linear relationship, and that an externally imposed magnetic field of as little as 70 G is required to kill the instability