Neutron irradiation induces a large number of vacancies and self-interstitial atoms (SIAs) that interact with hydrogen atoms (H) and degrade the mechanical properties of tungsten (W) in a fusion environment. Vacancies increase free space and trap H atoms, however, the effects of SIAs on trapping H atoms are still unclear since SIAs decrease free space. We therefore perform systematical \emph{ab initio} calculations to study the interactions of SIAs and SIAs clusters with H atoms in W. Our results suggest that SIA $\langle111\rangle$ dumbbell makes interstitial H atoms easy to accumulate in W. With accumulation of H atoms near a SIA $\langle111\rangle$ dumbbell, the binding energy decreases firstly and then levels off at about 0.3 eV. For comparison, the interactions of SIAs and SIAs clusters with helium (He) atoms are considered. It is found that SIAs and SIAs clusters can also act as trapping centers for interstitial He atoms. The combinations of SIAs with H and He hinder the fast movement of SIAs in W to annihilate with vacancies, increasing the concentrations of SIAs and vacancies in grain. SIAs and vacancies provide more sites for trapping H and He atoms and thus increase irradiation damage in W. We therefore suggest reducing retention of H isotopes and He in W to suppress irradiation damage.

中文翻译：

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自填隙原子对钨中氢和氦行为的影响

中子辐照会产生大量空位和自填隙原子 (SIA)，它们与氢原子 (H) 相互作用并降低聚变环境中钨 (W) 的机械性能。空位增加了自由空间并捕获了 H 原子，然而，由于 SIA 减少了自由空间，因此 SIA 对捕获 H 原子的影响仍不清楚。因此，我们进行系统的\emph{ab initio} 计算来研究 SIAs 和 SIAs 簇与 W 中 H 原子的相互作用。我们的结果表明 SIA $\langle111\rangle$ 哑铃使间隙 H 原子易于在 W 中积累。随着积累在 SIA $\langle111\rangle$ 哑铃附近的 H 原子中，结合能先降低，然后在 0.3 eV 左右趋于平稳。为了比较，考虑了 SIA 和 SIA 簇与氦 (He) 原子的相互作用。发现 SIAs 和 SIAs 簇也可以作为间隙 He 原子的俘获中心。SIAs与H和He的结合阻碍了SIAs在W中的快速运动以消灭空位，增加了谷物中SIAs和空位的浓度。SIA 和空位为捕获 H 和 He 原子提供了更多位点，从而增加了 W 中的辐射损伤。因此，我们建议减少 H 同位素和 He 在 W 中的保留以抑制辐射损伤。