Anderson localization of ballooning modes, quantum chaos and the stability of compact quasiaxially symmetric stellarators

M. H. Redi*, J. L. Johnson, S. Klasky, J. Canik, R. L. Dewar, W. A. Cooper

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    6 Citations (Scopus)

    Abstract

    The radially local magnetohydrodynamic (MHD) ballooning stability of a compact, quasiaxially symmetric stellarator (QAS), is examined just above the ballooning beta limit with a method that can lead to estimates of global stability. Here MHD stability is analyzed through the calculation and examination of the ballooning mode eigenvalue isosurfaces in the 3-space (s,α,θ k); s is the edge normalized toroidal flux, α is the field line variable, and θ k is the perpendicular wave vector or ballooning parameter. Broken symmetry, i.e., deviations from axisymmetry, in the stellarator magnetic field geometry causes localization of the ballooning mode eigenfunction, and gives rise to new types of nonsymmetric eigenvalue isosurfaces in both the stable and unstable spectrum. For eigenvalues far above the marginal point, isosurfaces are topologically spherical, indicative of strong "quantum chaos." The complexity of QAS marginal isosurfaces suggests that finite Larmor radius stabilization estimates will be difficult and that fully three-dimensional, high-n MHD computations are required to predict the beta limit.

    Original languageEnglish
    Pages (from-to)1990-1996
    Number of pages7
    JournalPhysics of Plasmas
    Volume9
    Issue number5
    DOIs
    Publication statusPublished - May 2002

    Fingerprint

    Dive into the research topics of 'Anderson localization of ballooning modes, quantum chaos and the stability of compact quasiaxially symmetric stellarators'. Together they form a unique fingerprint.

    Cite this