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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
Nonlinear electron oscillations in a viscous and resistive plasma
1Department of Theoretical Physics, Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw, Poland. askor@fuw.edu.pl
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 28, 2010
Summary
This study analyzes nonlinear Langmuir waves in plasmas, considering viscosity and resistivity. It finds that plasma viscosity significantly impacts wave evolution, potentially splitting density maxima, while resistivity effects are negligible in typical hydrogen plasmas.
Area of Science:
- Plasma Physics
- Fluid Dynamics
- Wave Phenomena
Background:
- Investigates nonlinear, spatially periodic, long-wavelength electrostatic modes in electron-ion plasmas, known as Langmuir waves.
- Incorporates viscous and resistive effects into the analysis of these plasma oscillations.
Purpose of the Study:
- To determine the conditions for applying the cold plasma approximation to large-amplitude Langmuir waves.
- To derive a general nonlinear solution for electron fluid dynamics and Poisson's equation.
- To analyze the influence of plasma resistivity and viscosity on wave evolution.
Main Methods:
- Adoption of the cold plasma approximation for long-wavelength electrostatic modes.
- Derivation of a general nonlinear solution in parametric form using continuity, momentum transfer, and Poisson's equations.
- Analysis of the impact of plasma resistivity and viscosity on electron number density profiles over time.
Main Results:
- Plasma resistivity has a negligible effect on Langmuir waves in typical hydrogen plasmas.
- A cold, collisionless plasma model is applicable if the wavelength (λ) is much larger than a minimum value dependent on equilibrium density and temperature.
- Strong plasma viscosity can significantly alter the density profile, including splitting the largest density maximum.
Conclusions:
- The nonlinear time evolution of periodic initial electron number density profiles can be determined within the derived limitations.
- A critical condition exists for initial electron density to prevent blow-up of density maxima after half a plasma oscillation period.
- Viscosity plays a crucial role in modifying Langmuir wave behavior, especially at shorter wavelengths or higher viscosity.
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