Comparison of ITER performance predicted by empirical, semi-empirical and theory-based transport models

The values of Q = (fusion power)/(auxiliary heating power) predicted for ITER by transport model based on empirical confinement scaling, dimensionless scaling technique, and by theory-based transport models are compared. The energy confinement time given by the ITERH-98(y,2) scaling for the ITER scenario with a plasma current of 15 MA and plasma density 15% below the Greenwald value is 3.6 s with one technical standard deviation of ±14%. These data translate to a Q interval of [6.5,15]. Dimensionless scalings generally support these data although their uncertainties are larger. Theoretical transport models such as Weiland and MMM, are sensitive to temperature at the plasma boundary. According to these models, to achieve Q=10 in ITER the temperature at the top of the edge pedestal should be 2-4 keV. The values of Q predicted by these three methods overlap within the uncertainties. The sensitivity of Q to a variation of plasma parameters predicted by the different models will be discussed in the paper. (author)