Forced reconnection by external magnetic perturbation in toroidal plasmas

Ishii, Yasutomo

Magnetic perturbations applied to magnetically confined plasma cause the forced magnetic reconnection and lead to magnetic island formation. Such a change of the magnetic structure affects the plasma performance. In the theoretical studies and/or numerical simulation ones, many works treated the slab geometry or the cylindrical geometry focusing on fundamental process of the magnetic reconnection. On the other hand, magnetic confined plasma aiming for nuclear fusion reactor is confined in the toroidal geometry. In the toroidal geometry, if an external magnetic perturbation with a single helicity is applied, many modes with different helicities are excited through the side band mode couplings and affect the magnetic configuration. In this study, we will report results obtained by numerical simulation study about effects of the external magnetic perturbation applied to tokamak plasma with toroidal symmetry, especially about feature of externally driven magnetic islands.