2010 年 5 巻 p. S2029
Improvement of ion heat transport was observed in the core plasma heated by neutral beam injection (NBI) in the Large Helical Device (LHD). A peaked ion temperature profile with a steep gradient (an ion internal transport barrier, ion ITB) formed in the plasma. To investigate the formation conditions of the ion ITB, a simple definition of ITB based on the reversal of the temperature gradient between the core and the edge is proposed. An ion ITB formed in the low-collisionality regime of 1/ν with low density and high ion heating power in the LHD.