Optimization of plasma initiation scenarios in JT-60SA

Matsukawa, Makoto; Terakado, Tsunehisa; Yamauchi, Kunihito; Shimada, Katsuhiro; Cara, P.*; Gaio, E.*; Novello, L.*; Ferro, A.*; Coletti, R.*; Santinelli, M.*; Coletti, A.*

Reliable plasma initiation is very important in the nuclear fusion devices especially in superconducting tokamaks. Applicable breakdown electric field would be limited up to level of 0.5 V/m to suppress large AC losses in the superconducting magnet. Furthermore, induced current in the passive structure such as vacuum vessel and stabilizing plate would increased easily to the comparable level of plasma current with several hundred kA even in the case of ECH assist breakdown. Therefore, optimization of the applied voltage to the poloidal field coil is necessary for stable plasma initiation. In this paper, the rationalized plasma initiation scenario using cost effectively designed power supply system will be provided.