skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Role of the pressure force in the explosive dynamics of magnetic islands in double tearing modes

Abstract

The evolution of magnetic islands at two resonant surfaces during the development of a global tearing mode is investigated via numerical simulations of a reduced set of magneto-hydrodynamic equations in slab plasmas. The explosive dynamics of the islands resulting in an interchange follows a Rutherford-like regime, also referred to as a weakly coupled double tearing mode. It is found that the latent mechanism of this dynamics is the reduction of the total pressure around the opposite X-point and the abrupt growth is associated with an imbalance of the pressure around the islands. Once this imbalance is well established, each plasmoid is pushed to the opposite X-point, increasing the drive for the field merging. A feedback loop then takes place as the reconnection itself decreases the strength of the magnetic field between the tearing layers, i.e., reinforces the pressure imbalance. This loop accelerates reconnection, thus leading to the observed explosive growth.

Authors:
; ;  [1];  [2]
  1. Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Gokasho, Uji-shi 611-0011 (Japan)
  2. National Institute for Fusion Science, Oroshi-cho, Toki-shi 509-5292 (Japan)
Publication Date:
OSTI Identifier:
22046937
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 18; Journal Issue: 10; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPUTERIZED SIMULATION; MAGNETIC FIELDS; MAGNETIC ISLANDS; MAGNETOHYDRODYNAMICS; NUMERICAL ANALYSIS; PLASMA; PLASMA PRESSURE; PLASMA SIMULATION; SURFACES; TEARING INSTABILITY

Citation Formats

Janvier, M, Li, J, Kishimoto, Y, and Ishizawa, A. Role of the pressure force in the explosive dynamics of magnetic islands in double tearing modes. United States: N. p., 2011. Web. doi:10.1063/1.3646396.
Janvier, M, Li, J, Kishimoto, Y, & Ishizawa, A. Role of the pressure force in the explosive dynamics of magnetic islands in double tearing modes. United States. doi:10.1063/1.3646396.
Janvier, M, Li, J, Kishimoto, Y, and Ishizawa, A. Sat . "Role of the pressure force in the explosive dynamics of magnetic islands in double tearing modes". United States. doi:10.1063/1.3646396.
@article{osti_22046937,
title = {Role of the pressure force in the explosive dynamics of magnetic islands in double tearing modes},
author = {Janvier, M and Li, J and Kishimoto, Y and Ishizawa, A},
abstractNote = {The evolution of magnetic islands at two resonant surfaces during the development of a global tearing mode is investigated via numerical simulations of a reduced set of magneto-hydrodynamic equations in slab plasmas. The explosive dynamics of the islands resulting in an interchange follows a Rutherford-like regime, also referred to as a weakly coupled double tearing mode. It is found that the latent mechanism of this dynamics is the reduction of the total pressure around the opposite X-point and the abrupt growth is associated with an imbalance of the pressure around the islands. Once this imbalance is well established, each plasmoid is pushed to the opposite X-point, increasing the drive for the field merging. A feedback loop then takes place as the reconnection itself decreases the strength of the magnetic field between the tearing layers, i.e., reinforces the pressure imbalance. This loop accelerates reconnection, thus leading to the observed explosive growth.},
doi = {10.1063/1.3646396},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 10,
volume = 18,
place = {United States},
year = {2011},
month = {10}
}