Linear and nonlinear stability of drift-tearing mode

The drift-tearing mode stability is studied numerically using the (reduced) two fluid equations. With a set of experimental data as input, the mode is found to be driven unstable by the electron temperature gradient when the classical perpendicular electron heat conductivity is taken into account. In the nonlinear phase two saturation regimes are found, a small magnetic island regime existing for an intermediate electron diamagnetic drift frequency and a large island regime for a sufficiently high bootstrap current fraction.