发表机构
Columbia University（哥伦比亚大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对近全仿星器的高能粒子共振损失问题，开发了可微目标函数Δ_res，优化准轴对称构型后使高能粒子约束提升4倍，为电站仿星器的粒子损失抑制提供了有力工具。
AI 中文摘要
近全仿星器（near-omnigenous stellarators）易受高能粒子（EP）损失影响，原因是捕获的高能粒子与磁场的非全仿扰动之间存在共振。现有的 bounce-averaged 目标函数如 Γ_c、Γ_δ 和 Γ_α 针对的是漂移面与通量面的非共振错位，但未捕捉共振的对流或扩散运动。我们开发了近全仿场中捕获高能粒子 bounce 点的离散映射理论，其中由于进动频率与 bounce 频率的共振，会形成相空间岛。我们引入 Δ_res，这是一种可微的 bounce-averaged 目标函数，通过惩罚这些岛的宽度来促进相空间可积性。结合 Δ_res 与两项准对称性目标函数优化准轴对称构型，可通过位移低阶共振并形成高能粒子输运势垒，使高能粒子约束提升4倍。Δ_res 是应对电站相关仿星器中共振对流和扩散损失的强大工具。
英文摘要
Near-omnigenous stellarators are susceptible to energetic particle (EP) losses due to resonances between trapped EPs and non-omnigenous perturbations to the magnetic field. Existing bounce-averaged objectives such as $Γ_c$, $Γ_δ$ , and $Γ_α$ target the non-resonant misalignment of drift and flux surfaces, but they do not capture resonant convective or diffusive motion. We develop a discrete map theory for the bounce points of trapped EPs in near-omnigenous fields, in which phase-space islands form due to resonance between the precession and bounce frequencies. We introduce $Δ_{res}$, a differentiable, bounce-averaged objective function that penalizes the widths of these islands, promoting phase-space integrability. Optimizing a quasi-axisymmetric configuration using $Δ_{res}$ combined with a two-term quasi-symmetry objective yields a factor-of-four improvement in EP confinement by displacing low-order resonances and forming EP transport barriers. $Δ_{res}$ is a powerful tool to combat both resonant convective and diffusive losses in power plant-relevant stellarators.
