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Bremsstrahlung radiation from toroidal plasmas generated through hydrodynamic shear.
Sean Mendoza1, Morteza Gharib2
1Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, 91125, USA. smendoza@caltech.edu.
Scientific Reports
|March 27, 2025
Summary
Bright visible light from argon plasma is caused by bremsstrahlung radiation. This study reveals distinct electron temperature and density phases within the plasma, suggesting self-confinement in this unique plasma configuration.
Area of Science:
- Plasma Physics
- Atomic Physics
- Spectroscopy
Background:
- Toroidal plasmas can exhibit unexpected light emission.
- Argon plasma's visible light spectrum differs from nitrogen or helium under similar conditions.
Purpose of the Study:
- Investigate the source of visible light in toroidal argon plasma.
- Characterize electron temperature (Te) and density (ne) distributions.
- Explore the plasma's self-confinement properties.
Main Methods:
- Generation of toroidal argon plasma via extreme hydrodynamic shear.
- Multispectral imaging for spatial analysis.
- Calculation of electron temperature and density from spectral data.
Main Results:
- Visible light emission identified as bremsstrahlung radiation from electron-neutral argon atom scattering.
- Spatial mapping revealed two distinct plasma phases: high Te/low ne inner ring and low Te/high ne outer region.
- A sharp boundary (<10 µm) was observed between these phases.
Conclusions:
- Bremsstrahlung radiation explains the anomalous visible light in argon plasma.
- The observed plasma phases and boundary suggest intrinsic self-confinement.
- The findings offer insights into controlling and understanding plasma behavior.
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