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 E DDYCAL code. TSPS code simulates plasma evolutions and EDDYCAL code perform s the eigenmode analysis of the eddy currents. The agreements between the e xperiment and the simulation are acceptable. The maximum discrepancy of the vessel currents between the simulation results and the experimental measur ements is about 30%. The plasma initiation is simulated from the initial ma gnetization until the plasma current grows 120 kA. It is found that the loc ation of the initial plasma growth is determined by the positional stabilit y. The negative voltage spike during the hi-drop and the evolution of the p lasma obtained in the simulation of the disruption are consistent with the experiment. It is shown that the simulation of the plasma with runaway elec trons is possible if the information on the runaways is provided. The field configuration, which is responsible to the generation of runaway electrons , is discussed. (C) 1999 Elsevier Science S.A. All rights reserved.