Evaluation of heat and particle controllability on the JT-60SA divertor

Abstract

The JT-60SA divertor design has been established on the basis of engineering requirements and physics analysis. Heat and particle fluxes under the full input power of 41MW can give severe heat loads on the divertor targets, while the allowable heat load is limited below 15MW/m2. Dependence of the heat flux mitigation on a D2 gas-puff is evaluated by SONIC simulations for high density (ne_ave∼1×1020m−3) high current plasmas. It is found that the peak heat load 10MW/m2 with dense (ned>4×1020m−3) and cold (Ted, Tid⩽1eV) divertor plasmas are obtained at a moderate gas-puff of Γpuff=15×1021s−1. Divertor plasmas are controlled from attached to detached condition using the divertor pump with pumping-speed below 100m3/s. In full non-inductive current drive plasmas with low density (ne_ave∼5×1019m−3), the reduction of divertor heat load is achieved with the Ar injection.