A Single-Ended ``Q Machine'' with Pulsed Emitter

A simplified version of a single-ended ``Q machine'' operating in the atomic beam mode is described. A highly ionized, low temperature, cesium plasma is generated from the contact ionization of a monatomic cesium beam on a conical, closely wound, hot tungsten, spiral filament. The filament is heated by repetitively pulsing the current passing through it to allow periods in time where no voltage appears across the hot tungsten surface. This technique eliminates the necessity of heating a solid tungsten plate by electron bombardment. Electron densities from 1×1010 to 4×1011/cm3 have been achieved at confining magnetic fields ranging from 0–3200 G. During the period in which the filament current is pulsed off, the filament, electron, and microwave radiation temperatures are all approximately equal.