Role of the Electron Temperature in the Current Decay during Disruption in JT-60U

The effect of the electron temperature Te on the plasma current decay after the mini-collapse was investigated for the disruption in JT-60U owing to a massive neon gas puff by using the disruption simulation code DINA. During the current quench in JT-60U, the fast electron temperature decrease is followed by a transient plasma current increase. This is called “mini-collapse”, typically occurring when the plasma current decreases to 80 90% of its value at the flattop phase. The plasma evolution after the mini-collapse was investigated using the DINA code for three assumed Te profiles: flat, broad, and peaked profiles. The time evolution of the plasma current, plasma center position, plasma cross section, and vacuum vessel current were not found to be sensitive to the Te profile after the mini-collapse. The plasma current after mini-collapse decreased owing to the plasma resistance, although it was previously found that the plasma current decrease during the initial phase of current quench was owing to the time derivative of the plasma inductance [Y. Shibara et al., Nucl. Fusion 50, 025065 (2010)].