The turbulence and transport expected in the SPARC tokamak Primary Reference Discharge (PRD) [P. Rodriguez-Fernandez et al., J. Plasma Phys. 86, 865860503 (2020)] have been investigated with the gyrokinetic code CGYRO [J. Candy et al., J. Comput. Phys. 324, 73–93 (2016)]. Linear and nonlinear simulations that focus on ion ($k_{\theta }{\rho }_s<1.0$) and electron-scale ($k_{\theta }{\rho }_s>1.0$) turbulence were used to probe the nature of the turbulence and the resulting transport in the fusion core. It is found that in the SPARC PRD, ion temperature gradient (ITG) turbulence is expected to dominate transport over most of the profile with some potential trapped electron mode impact in the near edge. Stiff turbulence is observed over a part of the plasma core such that SPARC's ion temperature profile will likely be pinned to just above the critical gradient for ITG. The role of electromagnetic turbulence, rotation, and electron-scale turbulence was investigated to provide some insight into the physics required to accurately predict SPARC performance via gyrokinetics. Additionally, predictions of impurity peaking for potential low- and high-Z SPARC first-wall materials are probed using ion-scale simulation. The dominance of low-k turbulence in SPARC provides a potential opportunity for more tractable prediction of plasma profiles using nonlinear gyrokinetics. This work is the first step toward full gyrokinetic profile prediction of SPARC kinetic profiles and the resulting fusion power and plasma gain.

中文翻译：

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SPARC 托卡马克中湍流和输运的陀螺动力学模拟

SPARC 托卡马克初级参考排放 (PRD) 中预期的湍流和输运 [P. 罗德里格斯-费尔南德斯等人。, J. 等离子体物理学。86, 865860503 (2020)] 已经使用陀螺动力学代码 CGYRO [J. 糖果等。, J. 计算。物理。324, 73–93 (2016)]。专注于离子的线性和非线性模拟（${克}_{\theta }{\rho }_{秒}<1.0$) 和电子秤 (${克}_{\theta }{\rho }_{秒}>1.0$) 湍流被用来探测湍流的性质和在聚变核心中产生的传输。发现在 SPARC PRD 中，离子温度梯度 (ITG) 湍流预计将主导大部分剖面的传输，在近边缘具有一些潜在的俘获电子模式影响。在等离子体核心的一部分上观察到剧烈的湍流，因此 SPARC 的离子温度分布可能会被固定在 ITG 的临界梯度之上。研究了电磁湍流、旋转和电子尺度湍流的作用，以深入了解通过陀螺动力学准确预测 SPARC 性能所需的物理学。此外，还使用离子尺度模拟探测了对潜在低和高 Z SPARC 第一壁材料的杂质峰化的预测。SPARC 中低 k 湍流的主导地位为使用非线性陀螺动力学更易于预测等离子体分布提供了潜在机会。这项工作是对 SPARC 动力学曲线以及由此产生的聚变功率和等离子体增益进行全面陀螺动力学曲线预测的第一步。