Influence of aspect ratio, plasma viscosity, and radial position of the resonant surfaces on the plasmoid formation in the low resistivity plasma in Tokamak

In the present paper, we systematically investigate the nonlinear evolution of the resistive kink mode in the low resistivity plasma in Tokamak geometry. We find that the aspect ratio of the initial equilibrium can significantly influence the critical resistivity for plasmoid formation. With the aspect ratio of 3/1, the critical resistivity can be one magnitude larger than that in cylindrical geometry due to the strong mode–mode coupling. We also find that the critical resistivity for plasmoid formation ηcrit decreases with increasing plasma viscosity in the moderately low resistivity regime. Due to the geometry of Tokamaks, the critical resistivity for plasmoid formation increases with the increasing radial location of the resonant surface.

日本語訳

本論文では、トカマク形状における低抵抗率プラズマ中の抵抗性キンクモードの非線形発展を系統的に調査する。初期平衡のアスペクト比がプラズモイド形成の臨界抵抗率に有意に影響を与え得ることを見出す。アスペクト比3/1の場合、強いモード間結合により、臨界抵抗率は円柱形状における値よりも一桁大きくなり得る。また、中程度に低い抵抗率領域では、プラズモイド形成の臨界抵抗率ηcritはプラズマ粘性の増加とともに減少することを見出す。トカマクの形状により、プラズモイド形成の臨界抵抗率は共鳴面の動径位置の増加とともに増加する。