Studies on a helical near field divertor

The proposed Dynamic Ergodic Divertor (DED) on the Torus Experiment for Technology Oriented Research (TEXTOR) has inspired the analysis of the near field of the perturbation current. For simplicity, the analysis is performed in cylindrical geometry. In the near field of a resonant perturbation current the field lines are diverted such that a helical divertor is formed. The configuration can be transformed topologically into the poloidal divertor. The required perturbation amplitude is about an order of magnitude smaller than the one required for the poloidal divertor. At this rather low perturbation current, the particle diversion efficiency is lower than that of a poloidal divertor, but amounts to more than 50%, which is quite considerable