Speaker
Description
Predictive modelling of plasma edge and divertor physics is a key challenge for ITER and future fusion power plants, where narrow operational margins require self-consistent treatment of turbulence, neutrals, magnetic geometry, and plasma-wall interactions. The TSVV3 project was established to advance European edge fluid turbulence modelling tools towards reactor-relevant predictive capability. We report here on its main outcomes and discuss identified remaining gaps.
The TSVV3 project coordinated developments across the main European edge turbulence codes (GBS, GRILLIX, FELTOR and SOLEDGE3X), combining advances in numerical methods, physical models and high-performance computing. The project addressed four major challenges: 1- realistic magnetic and wall geometries, 2- self-consistent neutral dynamics in detached divertor conditions, 3- turbulence modelling in high-performance plasma regimes, and 4- scalability towards reactor-sized simulations. Code developments were accompanied by validation against experiments on several European tokamaks and by applications to both tokamak and stellarator configurations.
The project enabled arbitrary axisymmetric magnetic geometries in all contributing European edge turbulence codes and extended simulations to three-dimensional configurations, including stellarators. Self-consistent neutral models based on fluid, kinetic and coupled Monte Carlo approaches were implemented, allowing first turbulence simulations in detached divertor regimes and demonstrating significant turbulence-induced scrape-off layer broadening in line with experimental results. Electromagnetic turbulence and improved collisional closures extended the applicability of fluid models towards high-β and low-collisionality plasmas, eventually enabling first self-consistent edge turbulence simulations in H-mode conditions. In parallel, substantial advances in numerical algorithms and GPU acceleration improved computational performance. Validation activities across multiple experimental devices have demonstrated the growing flexibility and predictive capability of these models.
While TSVV3 has significantly expanded the physics fidelity and applicability of European edge fluid turbulence codes, significant challenges remain on the path to self-consistent reactor-scale simulations. These include improved wall geometry treatment, scalable kinetic neutral modelling, impurity physics in three-dimensional turbulence simulations, and numerical strategies capable of addressing the spatial and temporal scales of fusion power plants. We will browse through some of these issues and highlight possible solutions currently explored in the TSVV-B project which took over TSVV3.