Curvature effects on the dynamics of tearing modes in tokamaks
The curvature effects on the dynamics of magnetic island evolution in tokamaks are investigated both theoretically and numerically. By taking into account perpendicular and parallel heat diffusion, a new dispersion relation is derived for tearing modes that match the linear and nonlinear results. This evolution equation allows a quantitative description over the whole range of island sizes. It predicts a nonlinear instability, i.e., growing magnetic islands in linearly stable magnetic configurations. All these predictions are in excellent agreement with full tridimensional linear and nonlinear magnetohydrodynamic (MHD) computations with the latest version of XTOR [K. Lerbinger and J. F. Luciani, J. Comput. Phys. 97, 444 (1991)]. These results have important consequences on the onset of neoclassical tearing modes because they predict a resistive MHD threshold.
Bibliographic Reference: An article published in: Physics of Plasmas, October 2001, Volume 8, Issue 10, pp. 4267-4270
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1063/1.1399056
Record Number: 200215624 / Last updated on: 2002-12-02
Original language: en
Available languages: en