Nonlinear gyrokinetic simulations correctly predict particle as well as ion and electron energy fluxes of high confinement plasmas with a negative triangularity cross sectional shape, showing that core transport in these plasmas is well described by standard gyrokinetic models. Experimentally inferred power balance fluxes are mostly reproduced within one standard deviation across a wide portion of the minor radius. Experimental conditions are reproduced by ion scale simulations, without the need to include density and temperature profile curvature effects. The experimental case is used as baseline to predict that the non-dimensional confinement scaling in negative triangularity plasmas increases strongly with plasma current while slightly degrading at increasing normalized pressure and decreasing collisionality. Recent experiments showed that low toroidal rotation negatively impacts confinement; consistent with the experiment, simulations predict that low rotational shear significantly affects confinement unless the plasma effective charge is maintained above a minimum level. Core confinement is predicted to significantly degrade in low aspect ratio devices.
この論文は、負の三角形断面を持つ高コンファインメントプラズマの粒子、イオン、電子エネルギー流束を正しく予測するジャイロキネティックシミュレーションについて報告しています。実験条件を再現し、プラズマ電流、規格化圧力、衝突周波数の影響を予測しています。また、低回転シアが閾値以下の場合、コンファインメントが大幅に劣化すると示唆しています。