Nanocomposite Scandate Tungsten Powder for High Current Density and Long Life Thermionic Cathodes Navy STTR FY2015.A Sol No.: Navy STTR FY2015.A Topic No.: N15A-T010 Topic Title: Nanocomposite Scandate Tungsten Powder for High Current Density and Long Life Thermionic Cathodes Proposal No.: N15A-010-0054 Firm: Vacuum Process Engineering, Inc. 110 Commerce Circle Sacramento, California 95815-4202 Contact: Neville Luhmann Phone: (530) 752-5414 Web Site: http://www.vpei.com/ Abstract: Vacuum Process Engineering Inc. in collaboration with the UC Davis millimeter wave research group proposes to develop a large scale production process for nanocomposite scandate tungsten powder for advanced high current density and long life thermionic cathodes that have been previously demonstrated by UC Davis to be superior to the commercially available state-of-the-art. The produced cathodes demonstrated over 100 A/cm^2 loading at 1050�C and over 40 A/cm^2 current loading at 850�C with lifetime of over 20,000 hours. The team will develop a process that could be scaled up to 300-500 kg per year and confirm the high quality of the produced powder by providing detailed powder evaluation data as well as cathode testing results in diode type and Pierce gun type test vehicles for pulsed and continuous wave operation. Finally, the team will provide cathode samples for independent evaluation in real devices by CPI, L-3 Electron Devices, Teledyne MEC, SLAC, and JPL as attested to by collaboration endorsement letters. Semicon Associates will provide necessary support for packaging development and delivery to the customers. Dr. Randall German will provide powder metallurgy consulting services to the team for development of reliable and consistent large scale powder manufacturing process. Benefits: The microwave industry will benefit immensely from availability of the nanocomposite scandate tungsten cathodes: the newly developed cathodes would extend the life of existing devices that are used in satellite communication tubes and in millimeter wave imaging systems (medical, security, and plasma fusion). These cathodes will also open opportunities for development of future high frequency devices bridging the terahertz gap with potential to be the next revolution in high data rate transmission. Expanding beyond the microwave tube industry, nanocomposite cathodes have potential to take over the electron beam lithography market providing higher quality and higher power beam without life degradation. Furthermore, the applications can be expanded to include electron beam welding and electron beam machining. Finally, nanocomposite cathodes have a potential to expand into the electric propulsion market by enhancing efficiency and expanding lifetime of the thrusters. Need for longer life cathodes in the electric thrusters has been established as a technical challenge by NASA and the nanocomposite scandate cathodes would allow NASA and other electric propulsion companies to overcome this challenge. Return