Characteristics of current quenches of major disruption in JT-60U

Kawano, Yasunori; Sugihara, Masayoshi; Ozeki, Takahisa; Shimada, Michiya

Since the major disruption determines key designing conditions of a vacuum vessel and plasma facing components of the tokamak fusion reactor, it is essential to understand the characteristics of major disruption. For this purpose, a disruption database has been constructed covering most of high performance discharges in JT-60U. By database analysis, for disruptions during the reverse shear discharges, we have found that fast current quench tends to occur at the regime of surface safety factor of just around 4 and internal inductance of around 0.5. This knowledge will provide basis to investigate the physics of current quench in the reverse shear discharges.