Effect of Resonant Magnetic Fields on the Development of Locked MHD Perturbations in the Plasma of the T‑10 Tokamak

The processes of development of locked magnetohydrodynamic (MHD) perturbations under conditions with all-metal tungsten limiters in the T-10 tokamak are considered. The system for generating external resonant magnetic fields based on eight saddle coils installed on the T-10 tokamak for investigating the conditions of destabilization of locked MHD perturbations is described. The effects of shielding of external magnetic fields by structural elements of the installation are analyzed. The studies showed the resonant nature of the influence of external magnetic perturbations on the development of MHD perturbations in the plasma of the T-10 tokamak, as well as an increase in the destabilization thresholds of locked MHD modes in high-density plasma. The experimental results are compared with a phenomenological model of the development of tearing modes in rotating plasma. Model calculations make it possible to describe the characteristic features of the influence of external resonant magnetic fields, including deceleration and stopping of angular rotation of magnetic islands and subsequent growth of locked MHD perturbations.