The impacts of sawtooth oscillations on impurity transport and accumulation in ITER

Full text of publication follows. The impacts of sawtooth oscillations on impurity transport and accumulation in ITER are investigated using 1.5D BALDUR integrated predictive modeling code. The impurity species considered are a combination of helium and beryllium. For each simulations, a linear combination of MMM95 anomalous transport and NCLASS neoclassical transport is used to describe both thermal and particles transports. Sawtooth oscillations are described using the Porcelli sawtooth triggering model and a modified Kadomtsev magnetic reconnection model. Self-consistent simulations for standard type ELMy H-mode and steady state ITER scenarios are carried out for duration of 1 hour with and without the effects of sawtooth oscillations. It is found that, for the standard ITER scenario, helium and beryllium densities tend to accumulate inside the plasma. Both helium and beryllium densities quickly rise and reach steady-state values. It is also found that sawtooth oscillations have a strong impact on suppression of the impurity accumulation. A sensitivity study, such as plasma engineering parameters, will be carried out to determine the impacts. (authors)