Development of a barium-free high-temperature cesium Tacitron

A barium-free, high-temperature, cesium Tacitron has been developed using a platinum, hollow cathode, emitter. The hollow cathode emitter used in our investigation is designed to enhance the current emission of a Tacitron cat hode without the use of barium in the switch. In a barium-cesium Tacitron, the barium is known to cover the surface of a molybdenum emitter lowering i ts work function. The barium however limits the lifetime of the Tacitron, u nless sophisticated seal technology is used in the manufacture of the Tacit ron, The hollow cathode emitter was operated at current densities from 2.5 A/cm( 2) up to 7.0 A/cm(2). Continuous operation of the Tacitron was demonstrated at 100-150 V and repetition rates of up to 5.8 kHz with measured voltage d rops of 3.5-9.0 V, The results of the experimental characterization are com pared to the computer model, and the applicability of this unique Tacitron design is discussed.