Pre-shot transport-equilibrium simulations and optimization of ITB scenarios for TCV

Developing automatic pre-shot simulations for tokamak operations is an important step towards validation of physics models and the improvement of control and pulse design strategies. We present results obtained with RAPTOR, a fast transport solver designed for real-time control [1] and scenario optimization [2]. Fast automated simulations of the core region have recently been developed for full TCV discharges, including L- and H-mode positive and negative trianguarity plasmas, only using information from the pulse planning ; and are coupled to the free-boundary Grad-Shafranov solver FBT [3] to solve the inverse equilibrium problem estimating the poloidal coil currents required to maintain the desired shape with realistic profile evolution.

We extended this predict-first pulse simulator with EC heating and current drive, by coupling TORBEAM [4] to RAPTOR and FBT, for fast validation of electron transport barriers (eITBs) scenarios. The EC and NBI heat deposition locations and timings are optimized to shape the current density profile, helping to develop robust scenarios for triggering and maintaining eITBs. These pre-shot simulations then serve to inform the RAPTOR real-time observer and feedforward coil current calculation, facilitating the control of kinetic profiles and plasma shape during ITB experiments.

[1] F. Felici et al. Nucl. Fus. 58(096006) 2018

[2] S. Van Mulders et al. Nucl. Fus. 64(026021) 2024

[3] F. Hofmann. Comp. Phys. Commun. 48(2) 1988

[4] E. Poli and al. Comp. Phys. Commun. 225, 2018