Dynamic mixing effects on hydrogen diffusion and retention in high Z materials

采用氢碳混合离子束辐照钨，研究钨碳层动态混合对起泡和氢扩散特性的影响。研究发现，只有0.3%以上的碳会强烈增强起泡。钨表面形成的钨碳混合层作为氢发射屏障，增强氢向体扩散，形成水疱。除碳外，还向离子束中加入聚变反应灰氦，研究氦对钨中氢行为的影响。只有0.1%的氦加入抑制了水泡的形成。在聚变反应堆中，聚变中子被照射到容器内的材料中。快中子会破坏这些材料。因此，研究辐照损伤对钨中氢行为的影响具有重要意义。为了研究这一问题，在混合离子束照射前，先用700 keV的氢负离子束照射钨。结果表明，高能氢离子束的预辐照抑制了小尺寸（<10μm）水泡的产生。未来，重复热负荷的影响也将被研究。

Hydrogen and carbon mixed ion beam was irradiated to tungsten to study the effects of dynamic mixing of tungsten and carbon layer on blistering and hydrogen diffusion characteristics. It was found that only 0.3% of carbon or more strongly enhanced blistering. Tungsten and carbon mixed layer formed on the tungsten surface acted as hydrogen emission barrier and enhanced hydrogen diffusion toward bulk, leading to blister formation. In addition to carbon, ash of fusion reaction, helium, was added to the ion beam to study the effect of helium on hydrogen behavior in tungsten. Only 0.1% of helium addition suppressed blister formation. In fusion reactors, fusion neutrons are irradiated to in vessel materials. Fast neutrons produce damages in these materials. Therefore it is important to study the effects of this irradiation damage on hydrogen behavior in tungsten. To study this subject, 700 keV hydrogen negative ion beam was irradiated to tungsten before mixed ion beam irradiation. It was found that pre irradiation of high energy hydrogen ion beam suppressed the production of small size (<10μm) blisters. In future, the effects of repetitive heat load will also investigated.