2005/01/26 by N. Arcis, Arcis, N., D. F. Escande +3
Earth and Planetary Sciences · Physics and Astronomy · #Geophysical and Geoelectrical Methods #physics.plasm-ph
paper · pdf · doi:10.48550/arxiv.physics/0501136
4 pages, submitted to Physical Review Letters
arxiv created 2005/01/26 · arxiv updated 2009/12/01
Within the traditional frame of reduced MHD, a new rigorous perturbation expansion provides the equation ruling the nonlinear growth and saturation of the tearing mode for any current gradient. The small parameter is the magnetic island width w. For the first time, the final equation displays at once terms of order w ln(1/w) and w which have the same magnitude for practical purposes; two new O(w) terms involve the current gradient. The technique is applicable to the case of an external forcing. The solution for a static forcing is computed explicitly and it exhibits three physical regimes.