发表机构
Oak Ridge National Laboratory; MIT Plasma Science and Fusion Center; Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine（橡树岭国家实验室; 麻省理工学院等离子体科学与聚变中心; 让·拉摩尔研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究针对低密度边缘等离子体中ICRF运行面临的冷等离子体理论奇异性问题，解析推导了碰撞消除奇异后的峰值长度尺度，并通过二维有限元模拟验证，指出仍需分辨热等离子体尺度的物理。
AI 中文摘要
在聚变发电厂中持续进行ICRF运行可能需要较低的边缘密度以减轻等离子体-壁相互作用，这一状态最近在WEST装置中以极低的杂质溅射实现。然而，冷等离子体理论预测在该状态下，无论是在低混杂共振处还是沿共振锥，射频电场都会出现奇异性，这引发了标准碰撞冷等离子体模型是否足以描述低密度边缘ICRF的问题。碰撞原则上可以消除这些奇异性，将其替换为有限但尖锐的峰值场。我们解析推导了这些峰值的长度尺度，并通过使用指数网格细化的二维有限元模拟加以确认，在需要处实现了微米级分辨率。我们得出结论，冷等离子体中的边缘碰撞并未消除对通常与热等离子体和伯恩斯坦波物理相关的长度尺度进行分辨的需求。
英文摘要
Sustained ICRF operation in a fusion power plant may require low edge densities to mitigate plasma-wall interactions, a regime which was recently achieved in WEST with very little impurity sputtering. Cold plasma theory, however, predicts singular radiofrequency electric fields in this regime, both at the lower hybrid resonance and along the resonance cones, raising the question of whether standard collisional cold plasma models suffice to describe low-density edge ICRF at all. Collisions in principle remove these singularities, replacing them with finite but sharply peaked fields. We derive these peak length scales analytically and confirm them with a 2D finite-element simulation using exponential mesh refinement, achieving micrometer resolution where needed. We conclude that edge collisions in cold plasma do not remove the need to resolve length scales ordinarily associated with hot-plasma and Bernstein-wave physics.
