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Building Langmuir Probes and Emissive Probes for Plasma Potential Measurements in Low Pressure, Low Temperature Plasmas
Published on: May 25, 2021
High accuracy plasma density measurement using hybrid Langmuir probe and microwave interferometer method.
C Deline1, B E Gilchrist, C Dobson
1Radiation Laboratory, University of Michigan, Ann Arbor, Michigan 48109, USA.
The Review of Scientific Instruments
|December 7, 2007
Summary
Researchers developed a new method for measuring plasma density using a Langmuir triple probe and radio frequency interferometers. This technique offers high spatial resolution and improved accuracy for magnetic nozzle physics research.
Area of Science:
- Plasma physics
- Propulsion systems engineering
- Spacecraft propulsion
Background:
- Accurate plasma density measurements are crucial for understanding magnetic nozzle physics.
- Existing methods may have limitations in spatial resolution or accuracy.
Purpose of the Study:
- To develop and validate a high spatial resolution plasma density measurement technique.
- To improve the accuracy of plasma density measurements in magnetic nozzle research.
Main Methods:
- Utilized a Langmuir triple probe scanned across an rf interferometer measurement chord.
- Normalized scanned profiles to microwave interferometer line-integrated density.
- Reconstituted line density by summing voltage readings for absolute density determination.
Main Results:
- Achieved measurement accuracy of 9%-15%, comparable to rf interferometers.
- The hybrid technique showed favorable comparison with scanning rf interferometers.
- The method appears more accurate than standard Langmuir probe theory alone.
Conclusions:
- The developed hybrid technique provides accurate, high spatial resolution plasma density measurements.
- This method is applicable to non-axisymmetric plasmas, enhancing its versatility.
- The technique advances the study of magnetic nozzle physics.
