Advanced Nano-Scandate Cathode

Scandate cathodes have the potential to replace conventional cathodes because of their improved emission characteristics. Nevertheless, it remains a challenge in this field to produce scandate cathodes with uniform surface emission in a reproducible manner. In this study, we report on scandate cathode emitters prepared from a novel nano-scandia/tungsten composite powder. Processing improvements have been developed to yield high-quality emitter surfaces. Emission testing demonstrates a greater than 200°C decrease (improvement) in knee temperature versus the standard M-type cathode. There is an on-going effort to quantify the work function of the cathode surface prior to and following activation.