Understanding the retention and recycling of hydrogen isotopes in liquid metal plasma-facing materials such as liquid Li, Sn, and Li-Sn are of fundamental importance in designing magnetically confined fusion reactors. We perform first-principles molecules dynamics simulations of liquid Li-Sn slab with inserted D atoms to provide microscopic insights into the interactions of D with Li-Sn liquid metal. We prepare two samples with low and high concentrations of D atoms. We observe evaporation of D₂ molecules out of the Li-Sn slabs in both concentrations of D. With detailed analysis, we unveil a cooperative process of forming D₂ molecules in liquid Li-Sn, where Li atoms act as catalytic centers to trap a D atom before another D comes nearby to form a molecule, and the surplus charges are transferred from D₂ to nearby Sn atoms. Furthermore, we predict a temperature window in the low concentration case in which D₂ molecules can escape to vacuum, while LiD molecules cannot. The above findings deepen our understanding of interactions between hydrogen isotopes and Li-Sn liquid metal.

在设计磁性约束聚变反应堆时，了解氢同位素在液态金属等离子体材料（例如液态Li，Sn和Li-Sn）中的保留和循环利用至关重要。我们对插入D原子的液态Li-Sn平板进行第一性原理分子动力学模拟，以提供D与Li-Sn液态金属相互作用的微观见解。我们准备了两个D浓度低和高的样品。我们观察到在两种浓度的D中，D ₂分子都从Li-Sn平板中蒸发出来。通过详细分析，我们揭示了形成D ₂的协同过程。液态Li-Sn中的一个分子，其中Li原子充当催化中心以捕获一个D原子，然后另一个D形成附近的分子，多余的电荷从D ₂转移到附近的Sn原子。此外，我们预测了低浓度情况下的温度窗口，其中D ₂分子可以逃逸到真空，而LiD分子则不能。上述发现加深了我们对氢同位素与Li-Sn液态金属之间相互作用的理解。