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Electron temperature measurement from neutral atomic tungsten emission line ratio
Steven F Adams1, Chase S Murray2, Neil A Pohl2
1Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, USA.
The Review of Scientific Instruments
|January 6, 2025
Summary
This study introduces a new method to measure plasma electron temperature using tungsten atomic emission lines. The technique calibrates against laser Thomson scattering, enabling future measurements without this complex equipment.
Area of Science:
- Plasma Physics
- Atomic Spectroscopy
Background:
- Accurate measurement of electron temperature is crucial for understanding plasma behavior.
- Existing methods like laser Thomson scattering can be complex and expensive.
Purpose of the Study:
- To develop and validate a novel method for determining plasma electron temperature.
- To utilize atomic tungsten emission spectra for temperature diagnostics.
Main Methods:
- Spectral analysis of atomic tungsten emission lines (400.88 and 401.52 nm).
- Measurement of line intensity ratios in the post-discharge region of a pulsed air plasma.
- Calibration of the tungsten emission method using laser Thomson scattering.
Main Results:
- A correlation between the intensity ratio of specific tungsten lines and electron temperature was established.
- A calibration factor was derived, representing a new ratio of Einstein A coefficients.
- The tungsten emission method was validated against laser Thomson scattering.
Conclusions:
- Atomic tungsten emission provides a viable diagnostic for electron temperature in plasmas.
- The developed method offers a simpler alternative to laser Thomson scattering for future measurements.
- The derived calibration factor enables direct electron temperature determination using tungsten line ratios.
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