Neutron irradiation-induced recrystallization simulation for tungsten in nuclear fusion device

Abstract

In magnetic confinement nuclear fusion devices, Tungsten (W) stands out as the most promising material for plasma-facing components, especially for divertor targets exposed to high neutron loads and high heat flux. However, the harsh operational conditions subject W undergoes significant degradation due to irradiation-induced defect production and irradiation-induced recrystallization, resulting in a modification of the original microstructure. These irradiation effects lead to a consequential deterioration in mechanical properties and component durability.This study implements a neutron irradiation-induced recrystallization (NIIR) modeling framework to quantify the recrystallization fraction in the W section of the plasma-facing components (PFCs). The simulation results reveal that the rate of neutron irradiation damage significantly impacts NIIR, leading to varying durations for achieving complete recrystallization in W at elevated temperatures. Furthermore, the half recrystallization time of W experiences a substantial reduction under neutron irradiation, resulting in a thicker recrystallized layer in W-PFCs compared to those without neutron irradiation but at the equivalent heat flux conditions.