Effect of ELM mitigation coils on losses of fast ions in ITER

Tani, Keiji*; Shinohara, Koji; Oikawa, Toshihiro*; Miyamoto, Seiji

ITER is planning to install ELM mitigation coils in the vacuum vessel. However, because the ELM mitigation coils produce a new error field in addition to those of the toroidal field ripple and the Test Blanket Modules, it is unclear if the error field from the ELM mitigation coils causes additional losses of fast ions and a consequent additional heat load on the first wall. We have investigated the effects of the ELM mitigation coils on the loss of fast ions using JAEA's orbit-following Monte-Carlo code. Results show that the loss of alpha particles is acceptably low at less than 1 %. The ELM mitigation coils, however, may cause a more significant loss of fast ions produced by NBI on the order of 5-6 %.