Gyrokinetic turbulent transport simulations on steady burning condition in D-T-He plasmas

TL;DR

This study uses gyrokinetic simulations to analyze turbulent transport in D-T-He plasmas, identifying conditions for steady burning and effects of impurities, turbulence, and flows on plasma confinement.

Contribution

First demonstration of gyrokinetic simulation-based evaluation of steady burning conditions with He-ash exhaust and D-T fuel pinch in ITER-like plasmas.

Findings

Imbalance in turbulent particle flux for D and T ions depending on density ratio.

Identification of profile regimes satisfying steady burning conditions.

Impact of zonal flows and nonthermal He-ash on plasma profile optimization.

Abstract

Ion temperature gradient(ITG) and trapped electron modes(TEM) driven turbulent transport in an ITER-like plasma is investigated by means of multi-species gyrokinetic Vlasov simulations with D, T, He, and real-mass kinetic electrons including their inter-species collisions. Beyond the conventional zero-dimensional power balance analysis presuming the global energy and particle confinement times, gyrokinetic-simulation-based evaluation of a steady burning condition with He-ash exhaust and D-T fuel inward pinch is demonstrated. It is clarified that a significant imbalance appears in the turbulent particle flux for the fuel ions of D and T, depending on the D-T density ratio and the He-ash accumulation. Then several profile regimes to satisfy Reiter's steady burning condition are, for the first time, identified by the gyrokinetic simulation. Also, the impacts of zonal flows and nonthermal He-ash on the optimal profile regimes are examined.