Potential contour shaping and sheath behavior with wall electrodes and near-wall magnetic fields in Hall thrusters

Journal Article · Mon Oct 15 04:00:00 EDT 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4762856· OSTI ID:22068850

Xu, K G ^[1]; Dao, H; Walker, M L. R. ^[2]

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1. Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)
2. Department of Aerospace Engineering, Georgia Institute of Technology, Atlanta, Georgia 30318 (United States)

Graphite electrodes are embedded within the discharge channel of a Hall effect thruster to focus ions for improved performance. Cusp-shaped magnetic fields are added around the electrodes to shield the electrodes from high electron current. Internal plasma potential measurements inside the discharge channel show that the presence of floating graphite does not significantly affect the potential contours at 150 V anode potential. Creation of closed contour pockets are observed with the electrodes biased 10 and 30 V above the anode potential. The electrodes also cause a compression of the acceleration region in the thruster. The cause of the changes in the potential contours is attributed to a shifting of discharge electrode from the anode to the electrodes and an expansion of the near-wall plasma sheath. The presence of the cusp magnetic fields is shown to affect the current collected by the electrodes, a behavior associated with modification of the plasma sheath properties due to magnetization of electrons.

• OSTI ID: 22068850
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 19; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANODES
CURRENTS
CUSPED GEOMETRIES
ELECTRIC DISCHARGES
ELECTRONS
GRAPHITE
HALL EFFECT
IONS
MAGNETIC FIELDS
MAGNETIZATION
PLASMA POTENTIAL
PLASMA SHEATH
THRUSTERS
WALL EFFECTS