Deuterium's Effect on Defect Production in Tungsten

Abstract

In fusion test reactors and power plants, one of the significant concerns is the retention of hydrogen isotopes in the wall materials. Especially the isotope tritium, which is radioactive, is of great concern. Knowing the retention of the other isotopes, such as deuterium, is also important due to several reasons. Deuterium is known to affect the mechanical properties of the wall material and most experiments are carried out on deuterium retention for its more safe use than tritium. In addition to affecting the mechanical properties of the wall material, deuterium has been observed to affect the defect accumulation in the material, if it is irradiated simultaneously by both energetic ions and deuterium. In this study, we investigate the phenomena and mechanisms behind why a greater defect accumulation is observed in tungsten when deuterium is present. We found that deuterium will both affect the defect production as well as the recombination rate of defects in tungsten.

Keywords: Tungsten, Deuterium, Irradiation, Molecular dynamics, Radiation damage