1TESTS OF 1-D TRANSPORT MODELS, AND THEIR PREDICTIONS FOR ITER

A number of proposed tokamak thermal transport models are tested by comparing their predictions with measurements from several tokamaks. The necessary data have been provided for a total of 75 discharges from C-mod, DIII-D, JET, JT-60U, T10, and TFTR. A standard prediction methodology has been developed, and three codes have been benchmarked; these 'standard ' codes have been relied on for testing most of the transport models. While a wide range of physical transport processes have been tested, no single model has emerged as clearly superior to all competitors for simulating H-mode discharges. In order to winnow the field, further tests of the effect of sheared flows and of the 'stiffness ' of transport are planned. Several of the models have been used to predict ITER performance, with widely varying results. With some transport models ITER's predicted fusion power depends strongly on the 'pedestal ' temperature, but ~ 1GW (Q=10) is predicted for most models if the pedestal temperature is at least 4 keV. 1