1 EX/P3-22 Driving Mechanism of Toroidal Rotation and Momentum Transport in JT-60U

Abstract. The driving mechanism of toroidal rotation and the momentum transport are studied, utilizing near-perpendicular neutral beam injection (PERP-NBI), co tangential and counter tangential NBI in JT-60U. Main results are as follows: (i) fast ion losses due to the toroidal field ripple induce the toroidal rotation in the direction antiparallel to the plasma current, i.e. counter (CTR) direction in the peripheral region, (ii) the magnitude of CTR rotation increases with increasing the ripple loss power in the peripheral region. (iii) Diffusive and non-diffusive terms of momentum transport are evaluated from the transient analysis by using the momentum source modulation experiment. Fast ion losses which locally induce the edge CTR rotation have been used as a novel momentum source. (iv) Parameter dependence of these transport coefficients i.e. the toroidal momentum diffusivity and the convection velocity Vconv, and the relation between heat and momentum diffusivities are investigated in L and H-mode plasmas systematically. The toroidal momentum diffusivity increases with increasing heating power, and decreases with increasing the plasma current in L-mode plasmas. The H-mode exhibits momentum diffusivity better than L-mode. Experiments indicate a positive correlation between the momentum and thermal transport at constant density. (v) We have also found that toroidal rotation velocity profiles in low plasmas can be almost explained by momentum transport considering diffusivity and convective velocity estimated from the transient momentum transport analysis. 1