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Effect of shaping on turbulent dynamics in reversed-field pinch simulations

Published online by Cambridge University Press:  29 November 2021

Robert Chahine ,
Kai Schneider Open the ORCID record for Kai Schneider [Opens in a new window]  and
Wouter J.T. Bos Open the ORCID record for Wouter J.T. Bos [Opens in a new window]
Robert Chahine
Affiliation:
Univ Lyon, CNRS, Ecole Centrale de Lyon, INSA Lyon, Univ Claude Bernard Lyon 1, LMFA, UMR5509, 69340 Ecully, France
Kai Schneider
Affiliation:
Aix-Marseille Université, CNRS, Institut de Mathématiques de Marseille (I2M), UMR 7373, 39 rue Joliot-Curie, 13453 Marseille cedex 13, France
Wouter J.T. Bos*
Affiliation:
Univ Lyon, CNRS, Ecole Centrale de Lyon, INSA Lyon, Univ Claude Bernard Lyon 1, LMFA, UMR5509, 69340 Ecully, France
*
†Email address for correspondence: wouter.bos@ec-lyon.fr
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Abstract

We study the influence of the shape of the plasma container on the dynamics of the reversed-field pinch (RFP). The geometries we consider are periodic cylinders with elliptical and circular-shaped cross-sections. Numerical simulations of fully nonlinear viscoresistive magnetohydrodynamics are carried out to illustrate how the plasma dynamics is affected by shaping. It is shown that independent of the plasma shape, the quantity $\beta$, comparing the hydrodynamic pressure to the magnetic pressure, decreases for increasing values of the Lundquist number, but the pressure gradient fluctuations remain roughly constant, when compared to the Lorentz force. Different elliptical shapes of the cross-section of the domain lead to the excitation of different toroidal (or axial) magnetic and dynamic modes. Furthermore, it is found that in a geometry with circular cross-section, a significant local poloidal angular momentum is observed, absent in the geometries with elliptical cross-section. Because the confinement is dominantly determined by plasma movement, and the dynamics of the velocity and magnetic field are modified by the modification of the geometry, shaping can thus affect the performance of RFP devices.

Keywords

MHD and ElectrohydrodynamicsMHD turbulenceplasmas

Information

Type
Research Article
Information
Journal of Plasma Physics , Volume 87 , Issue 6 , December 2021 , 905870608
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Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press

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Footnotes

‡

Present address: Rio Tinto Aluminium, Voreppe, France.

References

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