ION-TRANSPORT ANALYSIS OF A HIGH BETA-POLOIDAL JT-60U DISCHARGE

The high beta-poloidal discharge number 17110 in JT-60U (JT-60 Team, I AEA, Vienna, 1993) that develops an internal transport barrier is anal ysed for the transport of ion energy and momentum. First, the classica l ion temperature gradient stability properties are calculated in the absence of sheared plasma flows to establish the L-mode transport leve l prior to the emergence of the transport barrier. Then the evolving t oroidal and poloidal velocity profiles reported by Koide et al (1994 P hys. Rev. Lett. 72 3662) are used to show how the sheared mass flows c ontrol the stability and transport. Coupled energy-momentum transport equations predict the creation of a transport barrier. The balance of the steep ion temperature gradient against the magnetic shear and shea red mass flow is calculated for the profiles in the 17110 discharge.