Dynamics of resistive double tearing modes with broad linear spectra
Abstract
The nonlinear evolution of resistive double tearing modes (DTMs) with safety factor values q=1 and q=3 is studied with a reduced cylindrical model of a tokamak plasma. We focus on cases where the resonant surfaces are a small distance apart. Recent numerical studies have shown that in such configurations highm modes are strongly unstable and may peak around m=m{sub peak}{approx}10. In this paper, it is first demonstrated that this result agrees with existing linear theory for DTMs. Based on this theory, a semiempirical formula for the dependence of m{sub peak} on the system parameters is proposed. Second, with the use of nonlinear simulations, it is shown that the presence of fast growing highm modes leads to a rapid turbulent collapse in an annular region, where small magnetic island structures form. Furthermore, consideration is given to the evolution of lowm modes, in particular the global m=1 internal kink, which can undergo nonlinear driving through coupling to fast growing linear highm DTMs. Factors influencing the details of the dynamics are discussed. These results may be relevant to the understanding of the magnetohydrodynamic activity near the minimum of q and may thus be of interest for studies on stability and confinement of advancedmore »
 Authors:
 Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 6110011 (Japan)
 (France)
 (Japan)
 Publication Date:
 OSTI Identifier:
 20974822
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 2; Other Information: DOI: 10.1063/1.2446420; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CYLINDRICAL CONFIGURATION; KINK INSTABILITY; MAGNETIC ISLANDS; MAGNETOHYDRODYNAMICS; NONLINEAR PROBLEMS; NUMERICAL ANALYSIS; PLASMA; PLASMA CONFINEMENT; PLASMA SIMULATION; SAFETY; STABILITY; TEARING INSTABILITY; TOKAMAK DEVICES
Citation Formats
Bierwage, Andreas, Benkadda, Sadruddin, Hamaguchi, Satoshi, Wakatani, Masahiro, Equipe Dynamique des Systemes Complexes, UMR 6633 CNRSUniversite de Provence, 13397 Marseille, Center for Atomic and Molecular Technologies, Osaka University, 21 Yamadaoka, Suita, Osaka 5650871, and Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 6110011. Dynamics of resistive double tearing modes with broad linear spectra. United States: N. p., 2007.
Web. doi:10.1063/1.2446420.
Bierwage, Andreas, Benkadda, Sadruddin, Hamaguchi, Satoshi, Wakatani, Masahiro, Equipe Dynamique des Systemes Complexes, UMR 6633 CNRSUniversite de Provence, 13397 Marseille, Center for Atomic and Molecular Technologies, Osaka University, 21 Yamadaoka, Suita, Osaka 5650871, & Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 6110011. Dynamics of resistive double tearing modes with broad linear spectra. United States. doi:10.1063/1.2446420.
Bierwage, Andreas, Benkadda, Sadruddin, Hamaguchi, Satoshi, Wakatani, Masahiro, Equipe Dynamique des Systemes Complexes, UMR 6633 CNRSUniversite de Provence, 13397 Marseille, Center for Atomic and Molecular Technologies, Osaka University, 21 Yamadaoka, Suita, Osaka 5650871, and Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 6110011. Thu .
"Dynamics of resistive double tearing modes with broad linear spectra". United States.
doi:10.1063/1.2446420.
@article{osti_20974822,
title = {Dynamics of resistive double tearing modes with broad linear spectra},
author = {Bierwage, Andreas and Benkadda, Sadruddin and Hamaguchi, Satoshi and Wakatani, Masahiro and Equipe Dynamique des Systemes Complexes, UMR 6633 CNRSUniversite de Provence, 13397 Marseille and Center for Atomic and Molecular Technologies, Osaka University, 21 Yamadaoka, Suita, Osaka 5650871 and Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 6110011},
abstractNote = {The nonlinear evolution of resistive double tearing modes (DTMs) with safety factor values q=1 and q=3 is studied with a reduced cylindrical model of a tokamak plasma. We focus on cases where the resonant surfaces are a small distance apart. Recent numerical studies have shown that in such configurations highm modes are strongly unstable and may peak around m=m{sub peak}{approx}10. In this paper, it is first demonstrated that this result agrees with existing linear theory for DTMs. Based on this theory, a semiempirical formula for the dependence of m{sub peak} on the system parameters is proposed. Second, with the use of nonlinear simulations, it is shown that the presence of fast growing highm modes leads to a rapid turbulent collapse in an annular region, where small magnetic island structures form. Furthermore, consideration is given to the evolution of lowm modes, in particular the global m=1 internal kink, which can undergo nonlinear driving through coupling to fast growing linear highm DTMs. Factors influencing the details of the dynamics are discussed. These results may be relevant to the understanding of the magnetohydrodynamic activity near the minimum of q and may thus be of interest for studies on stability and confinement of advanced tokamaks.},
doi = {10.1063/1.2446420},
journal = {Physics of Plasmas},
number = 2,
volume = 14,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}

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