Comparison of deuterium retention in rolled and recrystallized tungsten with and without pre-damage

As the most promising candidate for plasma-facing material in thermonuclear fusion devices, the performance of tungsten under plasma exposure and neutron irradiation is a critical issue for tritium self-sufficiency and operational safety of future fusion devices. In this work, the deuterium behavior of rolled (Ro) and recrystallized (Rx) tungsten with and without pre-damage by energetic iron ions was investigated. Slow positron annihilation-Doppler broadening spectroscopy (SPA-DBS), scanning electron microscopy (SEM), and thermal desorption spectra (TDS) were used to characterize vacancy-type defects, deuterium-induced surface blistering, and deuterium retention of the investigated tungsten samples, respectively. The results show that the undamaged Ro and Rx tungsten have different types of vacancy defects and deuterium traps, whereas identical type vacancy defects and deuterium traps are found in the pre-damaged Ro and Rx. Changing the pre-damage distribution does not affect the type of deuterium traps in both Ro and Rx, further demonstrating that the given material state has little effect on the generation of irradiation-induced defects at room temperature. It is implicated that the impact of the material state on deuterium behavior is insignificant in future plasma-facing material where neutron irradiation will introduce numerous crystal defects.