A singular finite element technique for calculating continuum damping of Alfvén eigenmodes

Bowden, G. W.; Hole, M. J.

doi:10.1063/1.4907792

Title: A singular finite element technique for calculating continuum damping of Alfvén eigenmodes

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Abstract

Damping due to continuum resonances can be calculated using dissipation-less ideal magnetohydrodynamics provided that the poles due to these resonances are properly treated. We describe a singular finite element technique for calculating the continuum damping of Alfvén waves. A Frobenius expansion is used to determine appropriate finite element basis functions on an inner region surrounding a pole due to the continuum resonance. The location of the pole due to the continuum resonance and mode frequency is calculated iteratively using a Galerkin method. This method is used to find the complex frequency and mode structure of a toroidicity-induced Alfvén eigenmode in a large aspect ratio circular tokamak and is shown to agree closely with a complex contour technique.

Authors:

Bowden, G. W.; Hole, M. J. ^[1]

Research School of Physical Sciences and Engineering, Australian National University, Acton, ACT 0200 (Australia)

Publication Date:: Sun Feb 15 00:00:00 EST 2015

OSTI Identifier:: 22408069

Resource Type:: Journal Article

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 22; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; 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; ALFVEN WAVES; ASPECT RATIO; DAMPING; EIGENVALUES; FINITE ELEMENT METHOD; ITERATIVE METHODS; MAGNETOHYDRODYNAMICS; RESONANCE; TOKAMAK DEVICES

Citation Formats


                    Bowden, G. W., and Hole, M. J. A singular finite element technique for calculating continuum damping of Alfvén eigenmodes.  United States: N. p., 2015. 
        Web.  doi:10.1063/1.4907792.

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                    Bowden, G. W., & Hole, M. J. A singular finite element technique for calculating continuum damping of Alfvén eigenmodes.  United States.  https://doi.org/10.1063/1.4907792

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                    Bowden, G. W., and Hole, M. J. 2015.  
        "A singular finite element technique for calculating continuum damping of Alfvén eigenmodes".  United States.  https://doi.org/10.1063/1.4907792.

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@article{osti_22408069,

  title        = {A singular finite element technique for calculating continuum damping of Alfvén eigenmodes},

  author       = {Bowden, G. W. and Hole, M. J.},

  abstractNote = {Damping due to continuum resonances can be calculated using dissipation-less ideal magnetohydrodynamics provided that the poles due to these resonances are properly treated. We describe a singular finite element technique for calculating the continuum damping of Alfvén waves. A Frobenius expansion is used to determine appropriate finite element basis functions on an inner region surrounding a pole due to the continuum resonance. The location of the pole due to the continuum resonance and mode frequency is calculated iteratively using a Galerkin method. This method is used to find the complex frequency and mode structure of a toroidicity-induced Alfvén eigenmode in a large aspect ratio circular tokamak and is shown to agree closely with a complex contour technique.},

  doi          = {10.1063/1.4907792},

  url          = {https://www.osti.gov/biblio/22408069},
  journal      = {Physics of Plasmas},

  issn         = {1070-664X},

  number       = 2,

  volume       = 22,

  place        = {United States},

  year         = {Sun Feb 15 00:00:00 EST 2015},

  month        = {Sun Feb 15 00:00:00 EST 2015}

}

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