Effective Evaluation of the Impact of the Magnetic Ripple on the Field Line Topology in DTT: Preliminary Results

The tracking of magnetic field lines (FLs) in a Tokamak is a rather challenging issue because of the high computational burden required for field calculation and the high number of field points, especially in fully 3-D configurations. An effective scheme, based on a high-precision Chebyshev polynomials approximation of the field has been proposed to reduce the computational burden while guaranteeing the accuracy within suitable margins. In this article, the approach has been applied to evaluate the effect of the magnetic toroidal ripple on the scrape-off layer (SOL) of the reference configuration of the Divertor Tokamak Test (DTT) facility. The results demonstrate a significant impact on the last closed plasma magnetic surface but a limited effect on the magnetic load on the divertor surface. In addition, the article demonstrates that both effects depend on the specific plasma scenario analyzed and provides an interpretation key based on the analysis of the magnetic topology.