Laser induced fluorescence measurements of the cylindrical Hall thruster plume
- Aerospace Corporation, P.O. Box 92957-M2-341, Los Angeles, California 90009-2957 (United States)
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)
An investigation of a fully cylindrical Hall thruster was performed using laser induced fluorescence (LIF) to measure ion velocity profiles in the plume. The measurements confirm a previously reported 9% increase in the exhaust energy when the cathode keeper draws an excess current (overrun mode). Furthermore, the velocity directions in the plume remain relatively unchanged for the cusped and direct magnetic field configuration in both overrun and nonoverrun modes. Previously reported plume narrowing in the overrun mode was confirmed and found to be due to the shift of the acceleration and ionization regions toward the anode. The electric field inferred from the LIF measurements allowed calculation of the electron ExB drift. Close to the centerline of the thruster, electrons drift azimuthally with velocity decreasing away from the centerline, thus creating shear. This shear can be a source of plasma instabilities and influence electron transport. Further away from the centerline, electrons drift in the opposite direction with their velocity increasing with increasing radius. In that region, electrons rotate without shear.
- OSTI ID:
- 21432297
- Journal Information:
- Physics of Plasmas, Vol. 17, Issue 9; Other Information: DOI: 10.1063/1.3475433; (c) 2010 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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