Resonant magnetic perturbations and divertor footprints in poloidally diverted tokamaks

摘要

General formula describing both the divertor strike point splitting and widthof magnetic islands created by resonant magnetic perturbations (RMPs) in apoloidally diverted tokamak equilibrium is derived. Under the assumption thatthe RMP is produced by coils at the low-field side such as those used tocontrol edge localized modes (ELMs) it is demonstrated that the width ofislands on different magnetic surfaces at the edge and the amount of divertorsplitting are related to each other. Explanation is provided of aligned maximaof the perturbation spectra with the safety factor profile - an effectempirically observed in models of many perturbation coil designs.