Space charge saturated sheath regime and electron temperature saturation in Hall thrusters

Journal Article · Fri Jul 15 04:00:00 EDT 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.1944328· OSTI ID:20764433

Raitses, Y; Staack, D; Smirnov, A; Fisch, N J ^[1]

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1. Plasma Physics Laboratory, Princeton University, P. O. Box 451, Princeton, New Jersey 08543 (United States)

Existing electron-wall interaction models predict that secondary electron emission in Hall thrusters is significant and that the near-wall sheaths are space charge saturated. The experimental electron-wall collision frequency is computed using plasma parameters measured in a laboratory Hall thruster. In spite of qualitative similarities between the measured and predicted dependencies of the maximum electron temperature on the discharge voltage, the deduced electron-wall collision frequency for high discharge voltages is much lower than the theoretical value obtained for space charge saturated sheath regime, but larger than the wall recombination frequency. The observed electron temperature saturation appears to be directly associated with a decrease of the Joule heating rather than with the enhancement of the electron energy loss at the walls due to a strong secondary electron emission. Another interesting experimental result is related to the near-field plasma plume, where electron energy balance appears to be independent on the magnetic field.

• OSTI ID: 20764433
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRIC DISCHARGES
ELECTRIC POTENTIAL
ELECTRON COLLISIONS
ELECTRON EMISSION
ELECTRON TEMPERATURE
ELECTRONS
ION TEMPERATURE
ION THRUSTERS
JOULE HEATING
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
PLASMA
PLASMA GUNS
PLASMA SHEATH
RECOMBINATION
SPACE CHARGE
WALL EFFECTS