Abstract Transmutation elements are the essential products induced by high energy neutron radiation in plasma facing materials tungsten, which would bring the further effects on their point defects’ evolutions and service performance. Here, transmutation elements Re and Ta atom have been selected to assess the effects on vacancy and vacancy cluster in W material via first-principles calculations. The formation energy indicates mono-vacancy is more likely to form in W-Re system than pure W and W-Ta system. Both Re and Ta will reduce the diffusion barriers for the mono-vacancy migrations. The present calculations indicate that vacancy cluster is more inclined to grow up via combining the vacancy cluster rather than a single mono-vacancy. Re is favorable to the nucleation and growth of vacancy clusters, while Ta has a suppressive effect on the aggregation of small vacancy clusters. The emphasis analysis is obtained according the volumetric dependent strain. Vacancy dissociation calculations show that the dissociation of vacancy clusters is easier to begin with a single vacancy dissociation process.

中文翻译：

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嬗变元素Re和Ta对W体空位形成和解离行为的影响

摘要 嬗变元素是高能中子辐射在面向等离子材料钨中诱发的重要产物，它会进一步影响其点缺陷的演化和使用性能。在这里，已经选择嬗变元素 Re 和 Ta 原子通过第一性原理计算评估对 W 材料中空位和空位簇的影响。形成能表明单空位在 W-Re 系统中比纯 W 和 W-Ta 系统更容易形成。Re 和 Ta 都会降低单空位迁移的扩散势垒。目前的计算表明，空位集群更倾向于通过组合空位集群而不是单个单一空位来成长。Re有利于空位簇的成核和生长，而Ta对小空位簇的聚集有抑制作用。根据体积相关应变获得重点分析。空位解离计算表明，空位簇的解离更容易从单个空位解离过程开始。