Destabilization mechanism of the collisional microtearing mode in magnetized slab plasmas

The destabilization mechanism of the collisional microtearing mode driven by an electron temperature gradient is studied using theoretical analyses and gyrokinetic simulations including a comprehensive collision model, in magnetized slab plasmas. The essential destabilization mechanism of the microtearing mode is the lag of the parallel inductive electric field behind the magnetic field owing to the time-dependent thermal force and inertia force induced by the velocity-dependent electron-ion collisions. Quantitative measurements of the collision effects enable us to identify the unstable regime against collisionality and reveal the relevance of the collisional microtearing mode with existing toroidal experiments. A nonlinear simulation demonstrates that the microtearing mode does not drive magnetic reconnection with the explosive release and conversion of the magnetic energy.

Automated summary

The destabilization mechanism of the collisional microtearing mode driven by an electron temperature gradient is investigated using theoretical analyses and gyrokinetic simulations including a comprehensive collision model. The essential destabilization mechanism is the lag of the parallel inductive electric field due to time-dependent thermal force and inertia force induced by velocity-dependent electron-ion collisions. Quantitative measurements of collision effects identify the unstable regime against collisionality and reveal the relevance of the collisional microtearing mode with existing toroidal experiments. A nonlinear simulation demonstrates that the microtearing mode does not drive magnetic reconnection with explosive release and conversion of magnetic energy.