NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Performance of a Cylindrical Hall-Effect Thruster with Magnetic Field Generated by Permanent MagnetsWhile Hall thrusters can operate at high efficiency at kW power levels, it is difficult to construct one that operates over a broad envelope down to 100W while maintaining an efficiency of 45- 55%. Scaling to low power while holding the main dimensionless parameters constant requires a decrease in the thruster channel size and an increase in the magnetic field strength. Increasing the magnetic field becomes technically challenging since the field can saturate the miniaturized inner components of the magnetic circuit and scaling down the magnetic circuit leaves very little room for magnetic pole pieces and heat shields. An alternative approach is to employ a cylindrical Hall thruster (CHT) geometry. Laboratory model CHTs have operated at power levels ranging from the order of 50 Watts up to 1 kW. These thrusters exhibit performance characteristics which are comparable to conventional, annular Hall thrusters of similar size. Compared to the annular Hall thruster, the CHT has a lower insulator surface area to discharge chamber volume ratio. Consequently, there is the potential for reduced wall losses in the channel of a CHT, and any reduction in wall losses should translate into lower channel heating rates and reduced erosion. This makes the CHT geometry promising for low-power applications. Recently, a CHT that uses permanent magnets to produce the magnetic field topology was tested. This thruster has the promise of reduced power consumption over previous CHT iterations that employed electromagnets. Data are presented for two purposes: to expose the effect different controllable parameters have on the discharge and to summarize performance measurements (thrust, Isp, efficiency) obtained using a thrust stand. These data are used to gain insight into the thruster's operation and to allow for quantitative comparisons between the permanent magnet CHT and the electromagnet CHT.
Document ID
20090014105
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Polzin, Kurt A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Raitses, Yevgeny
(Princeton Univ. Princeton, NJ, United States)
Fisch, Nathaniel J.
(Princeton Univ. Princeton, NJ, United States)
Date Acquired
August 24, 2013
Publication Date
December 8, 2008
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
MSFC-2183
Meeting Information
Meeting: 3rd Spacecraft Propulsion Subcommittee (SPS) Meeting/ JANNAF Interagency Propulsion Committee
Location: Orlando, FL
Country: United States
Start Date: December 8, 2008
End Date: December 12, 2008
Sponsors: Department of the Army, Department of the Air Force, NASA Headquarters, Department of the Navy
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available