Because of new technology, it is now possible to offer higher electron-beam densities and longer cathode life at lower heater powers then ever before. this is a significant development for high-frequency space communications, ka band and above; in this area, the limiting factor on microwave power… More

There is a significant and growing NASA requirement for small efficient space communications amplifiers in the range of five- to 50-watts at 20 GHz and above. These powers are too high for solid state technology. Traveling wave tubes, on the other hand, are not very efficient at these low power… More

There is a significant and growing NASA requirement for small efficient space communications amplifiers in the range of five- to 50-watts at 20 GHz and above. These powers are too high for solid state technology. Traveling wave tubes, on the other hand, are not very efficient at these low power… More

This proposal describes a program for an improved impregnated dispenser cathode. It will first seek to verify and understand recent improvements in scandate cathodes by workers in China.To do this, it will conduct tests on these cathodes and it will study composition and fabrication procedures. … More

The proposal describes a low-risk program for solving the remaining problems on reservoir cathodes. The solution will allow production of a miniature cathode with at least 20 Amps/cm2 loading and a life greater than 50,000 hours. All dispenser cathodes are limited by their supply of barium. … More

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… More

We propose an improved cathode based on our novel theory of the role of scandium oxide in enhancing emission in tungsten-impregnated cathodes. Recent results have demonstrated the efficacy of nano-particle scandium oxide, but a detailed theory on the mechanism of operation has been lacking. Our… More

We propose a reservoir cathode to improve performance in both ion and Hall-effect thrusters. We propose to adapt our existing reservoir cathode technology to this purpose. Reservoir cathodes are the only emission sources that are capable of providing the necessary current density (>5.0 A/cm2)… More

We propose a hollow reservoir cathode to improve performance in ion and Hall thrusters. We will adapt our existing reservoir cathode technology to this purpose. Reservoir cathodes are the only emission sources that are capable of supplying the necessary current density (>5.0 A/cm2) and life… More