Kinetic equilibrium prediction at TCV using RAPTOR and FBT

Abstract We present results from a new Kinetic-Equilibrium Prediction workflow and shot preparation for full Tokamak à Configuration Variable (TCV) discharges, by coupling predict-first RAPTOR transport simulations with FBT inverse equilibrium calculations. RAPTOR is a 1.5D transport code which has been extensively used for plasma shot optimization and real-time modeling. We show that rapid pre-shot simulations can be performed directly using information from the pulse schedule across a wide range of plasma shapes and scenarios, given an estimate of the confinement quality factor H 98 ( y , 2 ) and line-averaged density. The resulting p ′ and T T ′ profiles are then provided to the pre-shot equilibrium computation performed by FBT—a static free-boundary solver routinely used at TCV—achieving convergence between the two codes in a few iterations. Finally, we show that this coupling, when integrated into the TCV shot preparation, improves the evaluation of the coil currents needed to match the target plasma shape; in particular providing an accurate estimate of critical quantities such as the internal inductance l i and normalized pressure β N , giving more realistic information to tokamak operators about the expected pulse behavior and enabling them to adjust the plan correspondingly.