Simulation studies of plasma initiation and disruption in JT-60U

The plasma initiation and the disruption observed in JT-60U experiment are simulated by using TSPS (Toroidally Symmetric Plasma Simulation) code and EDDYCAL code. TSPS code simulates plasma evolutions and EDDYCAL code performs the eigenmode analysis of the eddy currents. The agreements between the experiment and the simulation are acceptable. The maximum discrepancy of the vessel currents between the simulation results and the experimental measurements is about 30%. The plasma initiation is simulated from the initial magnetization until the plasma current grows 120 kA. It is found that the location of the initial plasma growth is determined by the positional stability. The negative voltage spike during the li-drop and the evolution of the plasma obtained in the simulation of the disruption are consistent with the experiment. It is shown that the simulation of the plasma with runaway electrons is possible if the information on the runaways is provided. The field configuration, which is responsible to the generation of runaway electrons, is discussed.