DOUBLE TEARING MODE IN PLASMA WITH MAGNETIC BRAIDING

Abstract

The linear behavior of the double tearing mode driven by anomolous electron viscosity effects associated with magnetic braiding is investigated within the framework of MHD. A two-space-scale analysis is performed and the result is used to obtain an approximate dispersion relation for the mode. If the seperation of the rational surfaces at x =±xs is sufficiently small, xs/ αyα)-11/15R-1/15, the growth rate is predicted to scale as R-1/15. With increa-sing seperation the mode makes a transition to R-1/3 scaling, where R = τv/τH. The R-1/5 scaling is shown to be correlated with violation of the constant-φ approximation.