Research progress on JT-60U in advanced steady-state operation

JT-60Uにおける先進定常運転の研究の進展

内藤 磨

Naito, Osamu

JT-60Uにおける最近の定常化研究の成果いついて報告する。これまでの高ポロイダルベータHモードに加えて、定常トカマクで想定される負磁気シア運転、プラズマの安定性を高めるための高三角度運転についての研究を進めた。負磁気シア運転では中心部での顕著な閉じ込めの改善を実現し、核融合増倍率0.63を達成した。また、負磁気シア運転の持続、高密度ダイバータとの共存にも成功した。高三角度運転では閉じ込めと安定性の向上により準定常的な高性能放電を持続させることに成功した。この他、負NBI装置の進展状況、ダイバータ改造計画、JT-60SU構想についての報告を行う。

Recent research progress on JT-60U in advanced steady-state operation is presented. High fusion performance of has been obtained in negative magnetic shear plasmas as well as in high- H-mode. A negative shear discharge is shown to have enhanced core confinement. Its sustainment and compatibility with radiative divertor are also explored. Stability and confinement are improved in high triangularity operation and a noninductive discharge with high integrated performance has been achieved. The installation of negative-ion-based neutral beam injection system on JT-60U has been completed and beam injection into plasmas has been started. A preparation for the modification of the present JT-60U's open divertor to a W-shaped semi-closed divertor, and a conceptual design and R&D for JT-60 Super Upgrade are in pregress.