(AASERT-97) Development of a Field Emitter Cathode for Low-Power Hall Thrusters
Final technical rept. 1 Jun 1997-31 Dec 2000
MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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Fuel-efficient electric propulsion EP systems such as the Closed-Drift Hall thruster CDT can greatly enhance the capability of small satellites by reducing spacecraft propellant mass while increasing sensor payload and Deltav. However, a major stumbling block to the development of low-power - 100 W CDTs is the absence of a suitable cathode. Conventional 6.4-mm hollow cathodes consume 20 W of power and 5 sccm of propellant, which is more than the total propellant flow rate of a 100-W CDT. Smaller hollow cathodes e.g., 3.2-mm are in development with the challenging goal of consuming 5 W of power. However, the minimum propellant flow rate of these cathodes is unlikely to dip much below 1 sccm. Our approach for providing electron emission for low-power CDTs is to use field emitter array cathodes FEACs as a replacement for hollow cathodes. AASERT funds were secured to support one student in a three-year program to investigate the use of FEAC technology with CDTs. The current-voltage characteristics and lifetime of several baseline cathode designs were evaluated over a wide range of pressures 10exp -10 to 10exp -6 Torr range in an ultra high vacuum FEAC test facility. FEAC performance models were also developed and compared with experimental results.
- Electrical and Electronic Equipment
- Electricity and Magnetism
- Electric and Ion Propulsion