Transition between internal transport barriers with different temperature-profile curvatures in JT-60U Tokamak plasmas.
A spontaneous transition phenomena between two states of a plasma with an internal transport barrier (ITB) is observed in the steady-state phase of the magnetic shear in the negative magnetic shear plasma in the JT-60U tokamak. These two ITB states are characterized by different profiles of the second radial derivative of the ion temperature inside the ITB region (one has a weak concave shape and the other has a strong convex shape) and by different degrees of sharpness of the interfaces between the L mode and the ITB region, which is determined by the turbulence penetration into the ITB region.
Ida
K
K
National Institute for Fusion Sciences, Toki, Gifu, Japan.
Sakamoto
Y
Y
Takenaga
H
H
Oyama
N
N
Itoh
K
K
Yoshinuma
M
M
Inagaki
S
S
Kobuchi
T
T
Isayama
A
A
Suzuki
T
T
Fujita
T
T
Matsunaga
G
G
Koide
Y
Y
Yoshida
M
M
Ide
S
S
Kamada
Y
Y