Emission studies on reservoir cathodes

We report improved emission from our miniature reservoir cathodes due to changes in emission material composition and processes. Also, the diffuser plug porosity and composition were adjusted. The activity curves on diode testers now exhibit knee temperatures of 970deg CB at 5 A/cm 2 . This is slightly above the ldquoMrdquo impregnated cathodes used as controls. Activation time was also reduced. The main improvement was introduction of sub-micron tungsten as activator in the reservoir and improved processes to protect emission material from water vapor. We present the data and describe the compositional and process changes that were made.