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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- and low-confinement modes in simple magnetized toroidal plasmas.
Paolo Ricci1, B N Rogers, S Brunner
1Centre de Recherches en Physique des Plasmas - Ecole Polytechnique Fédérale de Lausanne, Association EURATOM-Confédération Suisse, CH-1015 Lausanne, Switzerland.
Physical Review Letters
|July 23, 2008
Summary
Simulations reveal two plasma confinement regimes: low (L) and high (H). A transition to the high confinement regime occurs with increased plasma source or reduced vertical magnetic field, improving plasma stability.
Area of Science:
- Plasma Physics
- Fusion Energy Research
- Magnetohydrodynamics
Background:
- Interchange turbulence is a key factor in plasma confinement.
- Understanding plasma transport is crucial for fusion energy development.
- Magnetized toroidal plasmas are relevant to fusion devices.
Purpose of the Study:
- To investigate interchange turbulence in a magnetized toroidal plasma.
- To identify and characterize different turbulent regimes.
- To develop analytical models for plasma transport and confinement transitions.
Main Methods:
- Three-field numerical simulations were employed.
- Analytical evaluations were performed for the low confinement regime.
- Transition conditions were estimated and compared with simulation results.
Main Results:
- Two distinct turbulent regimes, low (L) and high (H) confinement, were identified.
- Analytical expressions for plasma gradients and fluxes in the L regime showed good agreement with simulations.
- A transition to the H regime was observed, characterized by velocity shear limiting perpendicular transport and steepening plasma profiles.
Conclusions:
- The study successfully characterized L and H confinement regimes in interchange turbulence.
- Analytical models developed for the L regime accurately predict simulation outcomes.
- The findings provide insights into plasma confinement transitions and stability in toroidal systems.
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