|PROPOSAL NUMBER:||05 T3.02-9700|
|RESEARCH SUBTOPIC TITLE:||Space Power and Propulsion|
|PROPOSAL TITLE:||Non-ambipolar Electron Source|
|SMALL BUSINESS CONCERN (SBC):||RESEARCH INSTITUTION (RI):|
|NAME:||Phoenix Nuclear Labs||NAME:||University of Wisconsin--Madison|
|ADDRESS:||301 N. Whitney Way||ADDRESS:||301 N. Whitney Way|
|STATE/ZIP:||WI 53705-2722||STATE/ZIP:||WI 53706-1609|
|PHONE:||(608) 345-3779||PHONE:||(608) 263-4970|
PRINCIPAL INVESTIGATOR/PROJECT MANAGER
TECHNICAL ABSTRACT (LIMIT 200 WORDS)
A device to produce electron beams from magnetized plasma created with rf fields combined with electron extraction by electron sheaths is proposed. The source can provide electrons for neutralizing positive ion beams emerging from ion thrusters or as a generic electron source. With hollow cathode sources currently employed to provide neutralizing electrons, operation is limited in time and/or current density by cathode deterioration. RF electron sources provide an alternative approach that does not consume electrode material. The current from this Non-ambipolar Electron Source (NES) exceeds the current normally extracted from conventional rf plasma sources by a factor of (mi/me)1/2 where mi and me are the ion and electron mass. Ions are lost to a negatively biased conducting cylinder with area Ai chosen to be Ai ≥ (mi/me)1/2 *Ae where Ae is the electron extraction area. Slots in the conducting cylinder allow the cylinder to serve as a Faraday shield to reduce capacitive coupling from the antenna to the plasma. Proposed phase 1 design improvements should result in electron currents comparable to hollow cathode sources with lower neutral gas flow in the inductive discharge phase and higher currents with helicon operation. Phase 2 will develop prototype sources suitable for spacecraft testing.
POTENTIAL NASA COMMERCIAL APPLICATIONS (LIMIT 150 WORDS)
Due to the absence of electron emitting surfaces, the NES design allows for longer operational lifetimes and lower gas consumption compared to hollow cathodes used on solar-powered spacecraft and satellites which use electric propulsion for orbital maneuvers and station keeping. This technology will serve NASA by creating a new generation of electron neutralizers which will be able to function with decreased energy and fuel consumption causing a reduction in launch and operational costs. This concept is consistent with NASA's new vision for reliable, long-life, high current neutralizers that will be necessary for the successful completion of missions in Earth orbit, and to the moon, Mars and beyond. Other terrestrial NASA applications that would benefit from the replacement of hollow cathodes include: producing protective thermal spacecraft coatings, plasma assisted thin film formation, and optical coating deposition for large telescopic mirrors.
POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (LIMIT 150 WORDS)
There are currently 100's of commercial satellites in earth orbit that use electric propulsion technologies for daily station keeping and orbital maneuvers. All of these systems are limited in operational lifetime by hollow cathode deterioration and fuel consumption. NES technology has the promise of extending lifetime while reducing the fuel consumption of ion neutralizers. The U.S. military, Boeing, L3 Comm, Pratt & Whitney, Aerojet, and other large aerospace programs would directly benefit from this technology as it would extend the operational lifetime of their satellites. A very large non-NASA market exists for hollow cathode sources over a wide range of industrial applications that could be upgraded by NES technology. These include electron beam evaporation, electron beam surface modification, thin film growth, plasma assisted chemical vapor deposition, plasma vapor deposition, electron beam curing, waste handling, metallizing packaging films, electron beam reactive deposition, and more.
|NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.|
TECHNOLOGY TAXONOMY MAPPING
Fundamental Propulsion Physics
Optical & Photonic Materials
Particle and Fields
Semi-Conductors/Solid State Device Materials
Sterilization/Pathogen and Microbial Control
Thermal Insulating Materials