Implantation and desorption of H isotopes in W revisited by object kinetic Monte Carlo simulation

Abstract

As the leading candidate of plasma-facing materials, tungsten is expected to withstand the influx of D-T plasma in future fusion reactors, which is known to cause damages to tungsten surface and give rise to T fuel retention. In this work, based on accurate density functional theory parameterization, we carried out a series of object kinetic Monte Carlo (OKMC) simulations to study the retention behavior of H isotopes in W. By directly comparing our simulations with existing experiments, we show that the OKMC model can accurately describe H implantation and desorption behavior in W, with excellent agreements found between experimental/simulated H annealing curves, thermal desorption spectra, and fluence dependence. Our OKMC model reveals primary trapping sites of H in these experiments, provides deeper understanding for experimental results, and offers quantitative theoretical assessment for H implantation and desorption in W.