Plasma rotation and wall effects on resistive wall mode in JT-60U

Takechi, Manabu; Matsunaga, Go; Ozeki, Takahisa; Aiba, Nobuyuki; Kurita, Genichi; Isayama, Akihiko; Koide, Yoshihiko; Sakamoto, Yoshiteru; Fujita, Takaaki; Kamada, Yutaka; JT-60 Team

This is the first experimental result which demonstrates the dependence of critical RWM onset of plasma rotation and beta on initial plasma rotation with the variation of the angular momentum input and without magnetic braking. In the JT-60U with newly ferretic wall installed, it is possible to produce high beta plasma tightly coupled with the wall (b/a=1.2) above . In near-zero plasma rotation, the RWM started to grow at = and with finite plasma rotation, the plasma pressure survives up to much higher level than that with small rotation. The observed critical beta onset and the RWM growth rate are discussed along with theoretical predictions using experimentally observed q-, pressure-, and rotation profiles. The critical rotation of RWM on JT-60U is less one-second times lower than previous report of other tokamaks.