Observation of Resistive Wa I l Modes in JT-60U

Resistive wall modes (RWM) associated with ideal magnetohydrodynamic current-driven (pN 2.4) kink modes with low toroidal mode number n (n = I ) have been identified in JT-60U. The pressure-driven RWM occurs at the plasma toroidal rotation of about 1~;~o the Alfv6n speed without clear continuous slowing down of the plasma toroidal rotation. Occurrence of n = I RWMS result in thermal quench accompanied by higher n (n ~ 2) modes. In the case of current-driven (- zero p) RWMs, a thermal quench occurs only at the peripheral region just after the RWM. In contrast, a thermal quench occurs in the whole plasma region following a drastic increase in the growth rate of the RWM from the order of ~:~-1 (1:~ is the resistive diffusion time of the wall) to larger than 102 1::*-1 in the case of