Nonlinear drift tearing modes

Temperature-Gradient-Driven Tearing Modes

The observation of spontaneous islands growth in tokamak experiments indicates that the tearing mode could also be linearly unstable. However, in the framework of resistive magnetohydrodynamics, previous works have demonstrated that drift effects, electron heat transport along magnetic field lines and ion Larmor radius effects have stabilizing effects. Recently, numerical calculations and analy...

Drift-tearing magnetic islands in tokamak plasmas

A systematic fluid theory of nonlinear magnetic island dynamics in conventional low, large aspect-ratio, circular cross-section tokamak plasmas is developed using an extended magnetohydrodynamics model that incorporates diamagnetic flows, ion gyroviscosity, fast parallel electron heat transport, the ion sound wave, the drift wave, and average magnetic field-line curvature. The model excludes th...

Plasma rotation effects on neoclassical tearing modes

The effect of an equilibrium sheared ow on the nonlinear evolution of a neoclassical tearing mode is investigated by estimating the inuence it has on the inner and outer layer dynamics of the mode. Two complementary approaches are adopted. A generalized Rutherford model calculation is carried out to estimate the ow contributions to the polarization current term in the inner layer. For the ou...

Quasi-linear evolution of tearing modes

Nonlinear interactions of tearing modes in the presence of shear flow

The interaction of two near-marginal tearing modes in the presence of shear flow is studied. To find the time asymptotic states, the resistive magnetohydrodynamic (MHD) equations are reduced to four amplitude equations, using center manifold reduction. These amplitude equations are subject to the constraints due to the symmetries of the physical problem. For the case without flow, the model tha...