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arXiv · 2210.11816

Predictions of improved confinement in SPARC via energetic particle turbulence stabilization

A. Di Siena·P. Rodriguez-Fernandez·N. T. Howard·A. Banon Navarro·R. Bilato·T. Goerler·1 E. Poli·G. Merlo·J. Wrigh·M. Greenwald·F. Jenko
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Abstract

The recent progress in high-temperature superconductor technologies has led to the design and construction of SPARC, a compact tokamak device expected to reach plasma breakeven with up to $25$MW of external ion cyclotron resonant heating (ICRH) power. This manuscript presents local (flux-tube) and radially global gyrokinetic GENE (Jenko et al 2000 Phys. Plasmas {\bf 7} 1904) simulations for a reduced-field and current H-mode SPARC scenario showing that supra-thermal particles - generated via ICRH - strongly suppress ion-scale turbulent transport by triggering a fast ion-induced anomalous transport barrier (F-ATB). The trigger mechanism is identified as a wave-particle resonant interaction between the fast particle population and plasma micro-instabilities (Di Siena et al 2021 Phys. Rev. Lett. {\bf 125} 025002). By performing a series of global simulations employing different profiles for the thermal ions, we show that the fusion gain of this SPARC scenario could be substantially enhanced up to $\sim 80\%$ by exploiting this fast ion stabilizing mechanism. A study is also presented to further optimize the energetic particle profiles, thus possibly leading experimentally to an even more significant fusion gain.

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A. Di Siena, P. Rodriguez-Fernandez, N. T. Howard, A. Banon Navarro, R. Bilato, T. Goerler, 1 E. Poli, G. Merlo, J. Wrigh, M. Greenwald, F. Jenko. 2022-10-21. Predictions of improved confinement in SPARC via energetic particle turbulence stabilization. https://doi.org/10.1088/1741-4326%2Facb1c7

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