USA flag logo/image

An Official Website of the United States Government

Non-ambipolar Electron Source

Award Information

National Aeronautics and Space Administration
Award ID:
Program Year/Program:
2006 / STTR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
Solicitation Number:
Small Business Information
Phoenix Nuclear Labs LLC
8123 Forsythia St Suite 140 Middleton, WI -
View profile »
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 1
Fiscal Year: 2006
Title: Non-ambipolar Electron Source
Agency: NASA
Contract: NNC06CB42C
Award Amount: $100,000.00


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.

Principal Investigator:

Noah Hershkowitz
Principal Investigator

Business Contact:

Gregory R. Piefer
Business Official/President
Small Business Information at Submission:

Phoenix Nuclear Labs
8123 Forsythia Street Suite 140 Madison, WI 53562

EIN/Tax ID: 203361665
Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Research Institution Information:
University of Wisconsin-Madison
301 N. Whitney Way
Madison, WI 53706
Contact: Stepahnie Gray
Contact Phone: (608) 263-4970
RI Type: Nonprofit college or university