Abstract of JORSTAR2 Project

Large scale plasma instabilities can be strongly influenced by the mutual interaction with currents flowing in conducting vessel structures. To study this, the non-linear MHD code JOREK has been coupled with the vacuum code STARWALL, which allows to include the effects of eddy currents in 3D conducting structures in non-linear MHD simulations and is currently being extended to halo currents. JOREK-STARWALL has already been applied to non-linear simulations of RWMs, VDEs, Disruptions, Quiescent H-Mode, penetration of RMP fields, and vertical kick ELM triggering.

JOREK-STARWALL has the potential to contribute to the understanding of fundamental physics questions regarding many types of large-scale plasma instabilities, the interpretation of related experimental observations, and predictions for ITER. The proposed project is required to address realistic wall structures which is of high interest to ITER, for instance to predict asymmetric forces acting on support structures during disruption events. STARWALL was already MPI parallelized in a 2016 HLST project. The JOREK-STARWALL coupling terms inside JOREK need to be MPI parallelized as well, which involves distribution of large matrices over MPI tasks, linear algebra operations on the distributed matrices, and parallel I/O. These optimizations are required to enable simulations with realistic wall structures containing a large number of wall triangles.