Anderson Localization of Ballooning Modes, Quantum Chaos and the Stability of Compact Quasiaxially Symmetric Stellarators

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

Princeton University. Plasma Physics Laboratory.

关键词: Axial Symmetry;    70 Plasma Physics And Fusion Technology;    Stellarators;    Ballooning Instability;    Larmor Radius;   

DOI  :  10.2172/788453
RP-ID  :  PPPL-3623
RP-ID  :  AC02-76CH03073
RP-ID  :  788453

美国|英语

来源: UNT Digital Library

【 摘 要 】

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, alpha, theta(subscript ''k'')]; s is the edge normalized toroidal flux, alpha is the field line variable, and q(subscript ''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.