Martynov A A, Medvedev S Yu, Villard L
Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, Russia.
Phys Rev Lett. 2003 Aug 22;91(8):085004. doi: 10.1103/PhysRevLett.91.085004. Epub 2003 Aug 21.
Observations of nearly zero toroidal current in the central region of tokamaks (the "current hole") raises the question of the existence of toroidal equilibria with very low or reversed current in the core. The solutions of the Grad-Shafranov equilibrium equation with hollow toroidal current density profile including negative current density in the plasma center are investigated. Solutions of the corresponding eigenvalue problem provide simple examples of such equilibrium configurations. More realistic equilibria with toroidal current density reversal are computed using a new equilibrium problem formulation and computational algorithm which do not assume nested magnetic surfaces.
托卡马克中心区域几乎为零的环向电流观测结果（“电流孔”）引发了关于核心区域存在极低或反向电流的环向平衡的问题。研究了具有空心环向电流密度分布（包括等离子体中心的负电流密度）的Grad-Shafranov平衡方程的解。相应特征值问题的解提供了此类平衡构型的简单示例。使用一种新的平衡问题公式和计算算法计算了具有环向电流密度反转的更现实的平衡，该算法不假定嵌套磁面。
