Integrated core-SOL-divertor modelling for DEMO with tin divertor

Abstract

This paper analyzes a possible operational space for the DEMO device with the tin divertor. The simulation is performed with the COREDIV code which self-consistently solves core and scrape-off layer transport equations for plasma and impurity. A simple model of divertor surface evaporation was included in the code. The simulation was performed for the DEMO 1 April 2015 configuration. Influence of the sputtering, prompt redeposition and evaporation of the liquid tin divertor was taken into account. Simulation without impurity seeding shown that plasma in DEMO with the tin divertor is characterized with higher than 80% radiation fraction, and 55MW of power to the plate. Power across the separatrix stays slightly below the L-H threshold. In spite of high radiation fraction seeding with additional impurity is necessary to reduce the power to the divertor targets to acceptable levels. In presence of the argon seeding power to the plate is reduced to 23MW, power across the separatrix reaches 150MW which is compatible with the H-mode operation.