Mixing of tungsten and carbon and tritium dynamics at fusion first wall

在聚变反应堆中，钨材料被认为是面向等离子体的材料，并被认为将形成碳化钨。因此，揭示氚的行为变化是聚变安全的重要问题。本文研究了碳离子(C^+)、氦离子(He^+)和氘离子(D_2^+)在不同注入条件下对钨的保留行为。结果表明，碳离子注入形成了辐照缺陷，保留在钨中的碳改变了氚的保留行为。此外，还发现氦离子辐照所形成的辐照缺陷和氚滞留也增加了。对于三重离子(C^+、He^+和D2^+)注入钨，结果表明，在氦离子注入形成的辐照缺陷上，氚主要被俘获。此外，与双离子(C^+和D_2^+)相比，钨表面的碳-碳键减少。结果表明，氦离子注入是碳的溅射，氦的滞留对氢同位素在块材中的扩散有影响。

In the fusion reactor, tungsten materials are considered to use as the plasma facing materials and it is thought that tungsten carbide will be formed. Therefore, it is important issue for fusion safety to reveal the tritium behavior changes. In this study, carbon ion (C^+), helium ion (He^+) and deuterium ion (D_2^+) were implanted into tungsten on various conditions, and the retention behavior of deuterium was clarified. As a result, it was shown that irradiation defects ware formed by carbon ion implantation and the deuterium retention behavior was changed by carbon retained in tungsten. In addition, it was suggested that the irradiation defects also formed by helium ion irradiation and deuterium retention increased. For the triple ions (C^+, He^+ and D_2^+) implantation into tungsten, it was shown that the deuterium was mainly trapped on irradiation defects formed by helium ion implantation. Moreover, the carbon-carbon bond on tungsten surface was decreased compared to that in the dual ion (C^+ and D_2^+) case. It was suggested that carbon was sputtered by helium ion implantation and the helium retention would have an influence on diffusion of hydrogen isotopes to bulk..