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Published on: November 3, 2016
Anomalous electron mobility in a coaxial Hall discharge plasma
N B Meezan1, W A Hargus, M A Cappelli
1Mechanical Engineering Department, Stanford University, Stanford, California 94305-3032, USA.
Summary
Anomalous electron mobility in Hall plasma accelerators is linked to plasma fluctuations near the channel exit. This finding supports a model where fluctuations enhance electron transport in highly magnetized regions.
Area of Science:
- Plasma Physics
- Space Propulsion
Background:
- Hall plasma accelerators are crucial for space propulsion.
- Understanding electron transport is key to optimizing accelerator performance.
Purpose of the Study:
- To investigate anomalous cross-field electron mobility in Hall plasma accelerators.
- To determine the factors influencing electron transport mechanisms.
Main Methods:
- Utilized nonintrusive laser-induced fluorescence (LIF) for velocity measurements.
- Employed electrostatic probe diagnostics to measure plasma properties.
- Compared experimental Hall parameters with classical and Bohm values.
Main Results:
- Electron mobility near the anode aligns with classical collision-driven transport.
- Near the channel exit, inferred Hall parameters approach the Bohm value (approximately 16).
- Intense plasma fluctuations correlate with enhanced electron transport.
Conclusions:
- Plasma fluctuations significantly enhance electron transport in highly magnetized regions of Hall accelerators.
- A model incorporating both elastic collisions and fluctuation-induced frequencies explains the observed Hall parameter.
- Findings suggest a more nuanced understanding of electron transport in magnetized plasmas is required.
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