Nano-Particle Scandate Cathode for Space Communications

We propose an improved cathode based on our novel theory of the role of scandium oxide in enhancing emission in tungsten impregnate cathodes. Recent results have demonstrated the efficacy of nano-particle scandium oxide, but a detailed theory on mechanism has been lacking. Our theory explains published data and point to an optimized cathode which we here propose to build and test at our facility. The cathode is the performance limiting component in high frequency linear beam amplifiers such as traveling wave tubes and klystrons. Bandwidth, data rates, numbers of channels, frequency and output power requirements are going up. The performance of linear beam amplifiers is acutely limited by the cathode limitations. Scandate cathodes offer a way to increase emission from current limits of about 10 A/cm2 to about 50 A/cm2.