Fast ion loss associated with RMP penetration

Since Resonant magnetic perturbation (RMP) demonstrate edge localized mode (ELM) suppression and/or mitigation in DIII-D and KSTAR, RMP became a most promising tool for ITER to control ELM. However, enhancement of fast ion loss has been behavior in KSTAR during RMP application and it became very crucial to understand the fast ion loss behavior in the presence of the non-axisymmetric magnetic field. In order to investigate the behaviors of the fast ions during RMP in KSTAR plasmas, fast-ion loss detectors (FILD) have been used intensively. In order to investigate relation between axisymmetric breaking and fast ion loss behavior, various spectrum of RMP has been applied. In addition, to control the RMP penetration, plasma rotation speed has been modulated using ECH heating. It has been observed that n=1 static RMP induced toroidally asymmetric fast ion loss with 90 degree of phase difference with maximum radial magnetic perturbation intensity. In addition, fast ion loss during RMP is following a power law to the level of toroidal rotation speed. (author)