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Accession Number ADA580308
Title Experimental Assessment of Double Langmuir Probe Analysis Techniques in a Hall Thruster Plume.
Publication Date Jul 2012
Media Count 29p
Personal Author B. E. Beal D. L. Brown J. M. Blakely
Abstract A recent theoretical study of double Langmuir probes led to development of improved analytical techniques that account for probe electrode sheath expansion in a low-temperature plasma environment. The proposed technique is based on analytical curve fitting to Laframboise's results, which enables double probe measurement of electron temperature and plasma density over a wide range of densities without advance knowledge of the probe radius relative to Debye length. In this investigation, the method was evaluated by comparing plasma properties from three double Langmuir probes of varying electrode diameter. Far-field measurements of a Hall thruster plume were conducted with each probe at two facility background pressures. Plasma characteristics were calculated using the proposed analytical technique, and compared to orbital motion limited and thin-sheath analyses in regions of the plume where these methods are valid. Results revealed equivalent plasma properties from each double probe geometry when using the proposed double probe analysis methodology, indicating the electrode sheath expansion is accounted for. Calculated plasma densities and electron temperatures were consistent with standard analysis techniques. These findings support the proposed double probe analysis method for examination of plasma properties over a wide span of the far-field plume using a fixed Langmuir probe design and a single analysis technique.
Keywords Background
Briefing charts
Curve fitting
Hall thrusters
Langmuir probes
Low temperature
Mathematical analysis

Source Agency Non Paid ADAS
NTIS Subject Category 46G - Plasma Physics
43F - Environment
72B - Algebra, Analysis, Geometry, & Mathematical Logic
81B - Electric & Ion Propulsion
Corporate Author Air Force Research Lab., Edwards AFB, CA. Propulsion Directorate West.
Document Type Technical report
Title Note Conference paper.
NTIS Issue Number 1325
Contract Number N/A

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