Observation of reduced heat transport inside the magnetic island O point in the large helical device.
Evidence for a reduction of heat transport inside the magnetic island O point is observed from the propagation of a cold pulse produced by a tracer encapsulated solid pellet in the Large Helical Device. A small peak and slow propagation of the cold pulse are observed inside the island. A significant result is that electron heat diffusivity inside the island is estimated to be 0.2 m(2)/s which is smaller than that outside the island by an order of magnitude.
National Institute for Fusion Science, 322-6 Orhoshi-Cho, Toki-City, 509-5292 Japan.
S
S
Inagaki
N
N
Tamura
K
K
Ida
Y
Y
Nagayama
K
K
Kawahata
S
S
Sudo
T
T
Morisaki
K
K
Tanaka
T
T
Tokuzawa