Nonlinear hybrid simulations of energetic particle modes in realistic tokamak flux surface geometry

実形状トカマク平衡における高エネルギー粒子モードの非線形ハイブリッドシミュレーション

Bierwage, A.; 藤堂 泰*; 相羽 信行; 篠原 孝司; 石川 正男; 矢木 雅敏

Bierwage, A.; Todo, Yasushi*; Aiba, Nobuyuki; Shinohara, Koji; Ishikawa, Masao; Yagi, Masatoshi

The nonlinear dynamics of energetic particles in tokamak plasmas and their interaction with MHD modes have previously been studied using models which include only the most essential ingredients in order to understand the fundamental processes. Work is now underway to carry out simulations with more detailed models in order to enhance our predictive capabilities with respect to the excitation of MHD modes and energetic particle transport, which is expected to play an important role in burning plasmas. The present work focuses on the role of the equilibrium geometry, comparing results obtained for circular and for realistic flux surface geometry. For this purpose, earlier studies of so-called Abrupt Large-amplitude Events (ALE) in JT-60U are revisited. The simulations are carried out with the hybrid code MEGA. For the simple geometry, results obtained with another hybrid code, HMGC, serve as a benchmark, which may show how the choice of the numerical implementation affects the results.