Error field penetration processes in magnetic island mode locking with the time-varying and fixed boundary perturbations are investigated numerically by using a two-dimensional resistive magnetohydrodynamic model in slab geometry. The evolution of various poloidal torques on the rational surface in the processes is analyzed in detail. In particular, three different states with the fixed boundary perturbations, viz. below the threshold (nearly locked regime), on the threshold (just locked regime), and above the threshold (strongly locked regime), are discussed and compared with the physical processes of the Rutherford regime.
Modeling of magnetic island formation in magnetic reconnection experiment