Modeling of runaway electron flux during tokamak disruptions by 3D relativistic orbit calculation

Matsuyama, Akinobu; Yagi, Masatoshi; Aiba, Nobuyuki; Kagei, Yasuhiro*

It is important to understand physics of REs during disruptions in order to develop reliable schems for mitigation of RE wall loads in ITER and tokamak reactors. A dominant role of magnetic perturbations on RE electron confinement has been demonstrated experimentally and theoretically. In this work, we study RE confinement in presence of external-kink perturbation by coupling 3D orbit following code ETC-Rel and linear ideal stability code MARG2D. It is shown that high-energy REs start to lose with lower perturbation amplitude with effect of curvature drift, and they are scattered longer distance in the poloidal direction as compared to low energy one. Concerning the heat load distribution, poloidal width of heat deposition is shown to depend strongly on the kink amplitude.