The influence of the toroidal field ripple on global H-mode performance in JT-60U has been investigated. The ripple size was varied by changing the plasma volume. The ripple losses have been measured by monitoring the local heat load to the first wall and have been simulated by the Orbit Following Monte Carlo code. The global H factors are found to be not very sensitive to the ripple size when the net input power is corrected for the ripple-trapped and banana-drift losses. These results are confirmed by theoretical analysis of the ripple-induced transport coefficients at rho =0.9.
Fast ion losses due to toroidal field ripple in JT-60U