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A 100 KW Class Applied-field Magnetoplasmadynamic Thruster
Published on: December 22, 2018
Magnetohydrodynamic mechanism for pedestal formation
1Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA.
Physical Review Letters
|October 27, 2011
Summary
Simulations show tokamak edge density pedestals form when poloidal velocity exceeds the sound speed, impacting plasma performance. These findings are crucial for understanding L-H transitions and high-performance tokamak operations.
Area of Science:
- Plasma physics
- Magnetohydrodynamics
- Fusion energy research
Background:
- Tokamak plasmas are key to fusion energy.
- Understanding edge plasma behavior is critical for performance.
- Conventional theories do not fully explain observed density profiles.
Purpose of the Study:
- Investigate the formation of density pedestals in tokamak edge plasmas.
- Explore the role of poloidal flow exceeding the sound speed.
- Relate findings to L-H transitions and pedestal formation.
Main Methods:
- Time-dependent, two-dimensional magnetohydrodynamic (MHD) simulations.
- Analysis of plasma behavior under varying edge poloidal flow conditions.
- Numerical modeling of plasma density and flow dynamics.
Main Results:
- A density pedestal forms around the entire tokamak edge when poloidal velocity exceeds the poloidal sound speed.
- Outboard pedestal formation is driven by transonic discontinuity.
- Inboard pedestal formation results from mass redistribution.
- A highly sheared flow forms at the transonic surface, correlating with pedestal development.
Conclusions:
- Edge poloidal flow exceeding the sound speed is a key mechanism for density pedestal formation.
- The simulation results offer insights into the L-H transition physics.
- Findings contribute to understanding pedestal formation in high-performance tokamak regimes.
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