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

在聚变反应堆中，考虑使用钨材料作为等离子体表面材料，并认为将形成碳化钨。因此，揭示氚的行为变化是保证核聚变安全的重要问题。本研究将碳离子（C^+）、氦离子（He^+）和氘离子（D_2^+）在不同条件下注入钨中，并阐明了氘的保留行为。结果表明，碳离子注入可形成辐照缺陷，而碳在钨中的保留改变了氘的保留行为。此外，还表明氦离子辐照后形成的辐照缺陷和氘潴留增加。对于注入到钨中的三离子（C^+、He^+和D_2^+），氘主要被困在氦离子注入形成的辐照缺陷上。此外，与双离子（C^+和D_2^+）情况相比，钨表面的碳碳键减少。结果表明，氦离子注入导致碳溅射，而氦的滞留会影响氢同位素向体体的扩散。

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..