In order to inform core performance projections and divertor design, the baseline SPARC tokamak plasma discharge is evaluated for its expected H-mode access, pedestal pressure and edge-localized mode (ELM) characteristics. A clear window for H-mode access is predicted for full field DT plasmas, with the available 25 MW of design auxiliary power. Additional alpha heating is likely needed for H-mode sustainment. Pressure pedestal predictions in the developed H-mode are surveyed using the EPED model. The projected SPARC pedestal would be limited dominantly by peeling modes and may achieve pressures in excess of 0.3 MPa at a density of approximately 3 × 1020m−3. High pedestal pressure is partially enabled by strong equilibrium shaping, which has been increased as part of recent design iterations. Edge-localized modes (ELMs) with >1 MJ of energy are projected, and approaches for reducing the ELM size, and thus the peak energy fluence to divertor surfaces, are under consideration. The high pedestal predicted for SPARC provides ample margin to satisfy its high fusion gain (Q) mission, so that even if ELM mitigation techniques result in a 2× reduction of the pedestal pressure,Q> 2 is still predicted.

中文翻译：

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SPARC 托卡马克 H 模式接入和边缘基座的投影

为了告知核心性能预测和偏滤器设计，对基线 SPARC 托卡马克等离子体放电的预期 H 模式访问、基座压力和边缘局部模式 (ELM) 特性进行了评估。对于全场 DT 等离子体，预计有一个清晰的 H 模式访问窗口，可用的设计辅助功率为 25 MW。H 模式维持可能需要额外的 α 加热。使用 EPED 模型调查了已开发的 H 模式中的压力基座预测。预计的 S​​PARC 基座将主要受到剥离模式的限制，并且可能在大约 3 × 10 的密度下实现超过 0.3 MPa 的压力20米-3. 强大的平衡成形部分实现了高基座压力，这已作为最近设计迭代的一部分而增加。预计能量大于 1 MJ 的边缘局部模式 (ELM)，并且正在考虑减小 ELM 尺寸的方法，从而降低偏滤器表面的峰值能量注量。SPARC 预测的高基座提供了充足的余量来满足其高融合增益（问) 任务，因此即使 ELM 缓解技术导致基座压力降低 2 倍，问> 2 仍被预测。