COBRA: An Optimized Code for Fast Analysis of Ideal Ballooning Stability of Three-Dimensional Magnetic Equilibria

R. Sanchez, S. P. Hirshman, J. C. Whitson, A. S. Ware

    Research output: Contribution to journalArticlepeer-review

    Abstract

    A new, fast, and accurate numerical algorithm to assess stability against ideal ballooning modes in general three-dimensional magnetic configurations of interest to controlled thermonuclear fusion is described. The code for ballooning rapid analysis (COBRA) performs this assessment by solving an eigenvalue problem in the form of a linear second-order ordinary differential equation along magnetic field lines in the configuration. An initial approximation for the eigenvalue is obtained from a fast second order matrix method. In COBRA, this approximate eigenvalue is further refined using a variational principle to obtain fourth-order convergence with the mesh size. Richardson's extrapolation is then applied to a sequence of eigenvalues to estimate the exact eigenvalue using the coarsest possible mesh, thus minimizing the computational time.

    Original languageEnglish
    Pages (from-to)576-588
    Number of pages13
    JournalJournal of Computational Physics
    Volume161
    Issue number2
    DOIs
    StatePublished - Jul 1 2000

    Keywords

    • Ballooning instabilities
    • Growth rate
    • Magnetohydrodynamics
    • Richardson's extrapolation
    • Spectrum of Stürm-Liouville operators
    • Stellarators

    Fingerprint

    Dive into the research topics of 'COBRA: An Optimized Code for Fast Analysis of Ideal Ballooning Stability of Three-Dimensional Magnetic Equilibria'. Together they form a unique fingerprint.

    Cite this