Investigation into the use of auxiliary discharges in thermionic generation

Abstract

Space charge compensation is studied in experimental auxiliary discharge thermionic generation devices containing Ne, Ar, Kr, Xe and mixtures of Ne-Ar, Ne-Kr, Ne-Xe, at pressures between 0.25 and 5.0 torr. The emitter and collector are similar barium aluminate matrix cathodes and the auxiliary cathode is an oxidecoated coiled tungsten filament. The space charge compensation improves as the atomic number of the gas increases. Optimum pressures occur for each gas: these are lower for the heavier gases. Gas mixtures show no significant advantage over single gases. Better space charge compensation is achieved when the auxiliary discharge is produced away from the emitter-collector region and when the auxiliary cathode temperature is reduced.