Abstract
A high confinement equilibrium with nearly zero toroidal current in the central region (a “current hole”) has been observed for the first time to persist stably for several seconds in the JT-60U tokamak. This observation indicates the possibility of stable tokamak operation without central toroidal current; the central current has previously been believed to be necessary in tokamaks. The radius of the current hole extended up to of the plasma minor radius. It was observed that the current hole was formed by the increase of the off-axis noninductive current.
- Received 26 June 2001
DOI:https://doi.org/10.1103/PhysRevLett.87.245001
©2001 American Physical Society