Numerical estimations of surface temperature evolution during multiple edge localized modes on EAST

Abstract

AbstractThe effects of thermal loads of multiple edge localized modes (ELMs) on the evolution of tungsten surface temperature on EAST have been performed by solving the one‐dimensional (1D) heat conduction equation. First, the fundamental properties of tungsten surface temperature evolution are investigated under stationary heat loads by a 1D heat conduction program. The exposure time for the steady‐state surface temperature and the corresponding surface temperature increase with the irradiated constant power density. When the power density is around 33 MW/m2, the steady‐state surface temperature comes up to the melting point of tungsten material. For the cases of ELMs, evolutions of irradiation power density at different ELM released energies (ΔWELMs) are calculated by particle‐in‐cell code SDPIC, which are used as input for the heat conduction program to simulate the impacts of multi‐ELMs on the tungsten surface temperature evolution. The tungsten surface temperature periodically oscillates accompanied by the burst and shutoff of ELMs under multi‐ELMs. The overall tendency of tungsten surface temperature rises first and then stabilizes within a certain temperature range. Parameter scans of different combinations of ΔWELMs and ELM frequency (fELMs) have been performed according to plasma conditions on EAST. The simulation results show that the tungsten surface will not suffer from melting under multi‐ELMs for EAST tokamak.