Kinetic Equilibrium Prediction at TCV using RAPTOR and FBT
Abstract
We present results from a new Kinetic-Equilibrium Prediction (KEP) workflow and shot preparation for full 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 H98(y,2) and line-averaged density. The resulting p' and TT' 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 and normalized pressure , giving more realistic information to tokamak operators about the expected pulse behavior and enabling them to adjust the plan correspondingly.
Cite
@article{arxiv.2603.01210,
title = {Kinetic Equilibrium Prediction at TCV using RAPTOR and FBT},
author = {C. E. Contré and A. Merle and O. Sauter and S. Van Mulders and R. Coosemans and G. Durr-Legoupil-Nicoud and F. Felici and O. Février and C. Heiss and B. Labit and A. Pau and Y. Poels and C. Venturini and B. Vincent and the TCV team and the EUROfusion Tokamak Exploitation Team},
journal= {arXiv preprint arXiv:2603.01210},
year = {2026}
}
Comments
26 pages, 21 figures