Properties of an rf produced magnetically confined nonneutral hot electron plasma

A magnetically confined, nonneutral hot electron plasma is produced by the acceleration and trapping of a low energy (approximately 1 keV) electron beam injected along the axis of an evacuated right circular cylindrical cavity resonator that is excited in the TE111 mode with up to 15 kW of rf power at 0.88 GHz. The cavity axis coincides with that of the static magnetic mirror field (B∼314 G, Rm=1.3:1). The nonneutral (for approximately 10–200 msec) hot electron plasma (We∼100 keV, Ne∼4×1011 electrons, and ne ∼4×109 cm−3) remains trapped for approximately 10 sec. There is a periodic ∇B precessional motion of the trapped electron cloud at a frequency of a few MHz.