RWM analyses of JT-60SA and JT-60U tokamak plasmas

Kurita, Genichi; Bialek, J.*; Fujita, Takaaki; Tamai, Hiroshi ; Matsukawa, Makoto; Matsunaga, Go; Takechi, Manabu; Tsuda, Takashi; Ozeki, Takahisa; Navratil, G. A.*; Ishida, Shinichi

JT-60SA is a tokamak device, being now designed at JAEA with collaboration of EU. One of the main purpose of JT-60SA is to realize the steady state plasma with high normallized beta values, 3.55.5. Our previous analyses have shown that the critical normalized beta value was 3.8 with the effect of the stabilizing structure with finite resitivity and the active feedback control. The critical beta value is very low compared to the critical normalized beta of 5.5 in the case using ideal stabilizing structure, which results in very low C value of 0.37 and bad efficiency of feedback control. To overcome these, we consider the new configuration of stabilizing structure and feedbacck control coil. The analyses are being carried out by VALEN code developed in Columbia University for new equiilibrium including transport analyses of JT-60SA plasma. We also present the results of analyses of experimental data of current driven and pressure driven RWM in JT-60U tokamak.