Modeling of fuel retention and hydrogen-isotope exchange removal from the pre-damaged tungsten material

摘要

The fuel retention and hydrogen-isotope exchange removal in the pre-damaged tungsten (W) have been investigated in the present work. The fuel retention code Hydrogen Isotope Inventory Processes Code (HIIPC) has been upgraded to model the isotope-exchange process. Three types of defects are taken into account in the pre-irradiated W, including the dislocation, mono-vacancy, vacancy cluster defects. The SRIM code is employed to calculate the radiation-damage defect distribution. Three phrases are modeled by controlling the source terms by using HIIPC code. (i) deuterium (D) retention phrase, pre-damaged W is irradiated by the D flux; (ii) waiting period, both of the D and hydrogen (H) fluxes are switched off; (iii) isotope exchange phase, the W material is irradiated by H atoms. It is found that enhancing implantation H fluence can reduce the retained D significantly. The simulation also confirms D retention increases with the irradiation damage (displacement per atoms, dpa), until saturation occur. De-trapping energy plays an important role on the D retention, especially for high material temperature. The modeling results are compared with the experiment measurement, showing the good agreement.