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Published on: May 25, 2021
Neoclassical toroidal plasma viscosity torque in collisionless regimes in tokamaks
1Institute for Energy Research-Plasma Physics, Forschungszentrum Jülich, Association EURATOM-FZJ, Trilateral Euregio Cluster, 52425 Jülich, Germany. y.sun@fz-juelich.de
Physical Review Letters
|January 15, 2011
Summary
Magnetic field irregularities boost plasma viscosity and slow plasma flow. This study presents a general solution for neoclassical toroidal plasma viscosity torque from nonaxisymmetric magnetic perturbations in tokamaks, showing significant angular momentum changes.
Area of Science:
- Plasma Physics
- Fusion Energy Research
- Magnetohydrodynamics
Background:
- Plasma viscosity is crucial for understanding plasma dynamics in fusion devices.
- Neoclassical Toroidal Viscosity (NTV) torque influences plasma rotation and confinement.
- Nonaxisymmetric Magnetic Perturbations (NAMPs) are known to break toroidal symmetry.
Purpose of the Study:
- To derive a general solution for NTV torque induced by NAMPs in collisionless tokamak regimes.
- To quantify the impact of magnetic field irregularities on plasma flow damping.
- To investigate the relationship between NAMP strength and plasma angular momentum changes.
Main Methods:
- Analytical derivation of the NTV torque in collisionless regimes.
- Analysis of plasma response to nonaxisymmetric magnetic perturbations.
- Mathematical modeling of plasma angular momentum evolution.
Main Results:
- Bumpiness in the magnetic field significantly enhances plasma viscosity.
- NAMPs lead to increased plasma flow damping rates.
- A small NAMP (0.1% of toroidal field strength) can cause substantial changes in plasma angular momentum.
Conclusions:
- Magnetic field perturbations are a critical factor in controlling plasma viscosity and rotation in tokamaks.
- The derived NTV torque solution provides a tool for predicting plasma behavior under NAMPs.
- Understanding NTV torque is essential for optimizing plasma confinement and stability in fusion reactors.
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