ITER SIMULATION EXPERIMENTS ON JET OF THE H-MODE POWER THRESHOLD, CONFINEMENT SCALING AND BETA-SATURATION

The results of a series of ITER simulation experiments on JET are desc ribed. A series of H-mode threshold experiments are shown to reproduce one of the standard power threshold scaling expressions that is being used to predict the power threshold in ITER. Then, from a series of e xperiments in which the Larmor radius scaling of ELMy H-modes is exami ned, it is concluded that the scaling of the confinement is gyro-Bohm- like provided the power levels are well above the threshold. Finally, we show that at high beta there is a dramatic reduction in the confine ment at beta(n) > 2.