Simulations of ITER start-up and assessment of limiter power loads

This paper presents the results of a modelling study conducted to estimate the power crossing the separatrix (P SOL ) in the ITER device during a standard start-up sequence. This is used to calculate the power intercepted by the start-up limiters and the resulting power load distribution. The models and methodologies applied to calculate P SOL and the power loads on the limiters are described in detail elsewhere ([e.g., M. Kobayashi et al., Nucl. Fusion. 47 (2) (2007) 61]) and only a brief mention of some of the main results is included here. These assessments show that for the range of conditions analysed, the maximum P SOL intercepted by the two ITER limiter start-up modules during the current ramp-phase is ∼6 MW. The peak power load to each limiter is calculated to be ∼5 MW/m 2 , but these values depends on assumptions on physical quantities (e.g., transport coefficients, i.e., D ⊥ and Χ ⊥ ), which are uncertain and still await confirmation by experiments. Recommendations are made for modelling and experiments to extend the study presented here.