Integrated modeling of dedicated ramp up experiments at TCV: towards predict first

Understanding the evolution of the plasma during the ramp up of the current is critical for scenario design, since the exact trajectory impacts stability, pulse duration and disruption avoidance. Prediction of internal inductance, stored energy and normalized plasma pressure can, for example, help setting up the control systems. Modelling of the ramp up at TCV was already performed in [1], but on a limited set of discharges. A new set of dedicated TCV ramp up experiments was performed to extend the physics understanding and validate the models on a wider set of conditions. Current trajectory, shape, magnetic field, density and impurity composition were varied and the experimental data were compared with predictions with QuaLiKiz [2] and TGLF [3] used to predict the turbulent transport within the HFPS [4]. Despite fair agreement in some of the discharges, points of failure of the modelling and differences between the transport models are highlighted. Scanning only one actuator for each experiment and calculating precise agreement metrics help to isolate the physics mechanisms at play and in identifying where the models require improvements. Finally, perspectives on leveraging high fidelity models for predict-first and scenario development will be presented.

[1] M. Marin et al. (2025) Nucl. Fusion 65 036015

[2] Citrin et al. (2017) Plasma Phys. Control. Fusion 59 124005

[3] Staebler et al. (2016) Phys. Plasmas 23 062518

[4] Romanelli M. et al. (2014) Plasma Fusion Res. 9 3403023