title: Reduction of ion thermal diffusivity inside a magnetic island in JT-60U tokamak plasma.
abstract: A peaked ion temperature profile is observed inside the magnetic island during mode locking after the back transition from H mode to L mode in JT-60U. The thermal diffusivity evaluated inside the magnetic island is 0.1 m(2)/s, which is much smaller than that outside the magnetic island by an order of magnitude. The present experiment gives clear evidence that ion heat transport inside a magnetic island can bifurcate and the transport level can be suppressed to the very low level associated with the strong flow shear at the boundary.
authors.affiliation: National Institute for Fusion Science, Toki, Gifu, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ida
authors.forename: K
authors.initials: K
authors.lastname: Kamiya
authors.forename: A
authors.initials: A
authors.lastname: Isayama
authors.forename: Y
authors.initials: Y
authors.lastname: Sakamoto