MICRISTRUCTURAL PROCESSES OF PLASMA INJECTION EFFECTS IN FUSION PLASMA-FACING MATERIALS

为了研究等离子体粒子注入对聚变堆等离子体组件的影响，对低能氢离子辐照过程中钼和钨的显微组织演变进行了原位观察。在钼中观察到离子能量对微观结构演化的强烈依赖性。循环生成，增长，缠结和由此产生的网络形成观察与离子的4keV及以上。另一方面，在2keV及以下观察到氢团簇。然而，在钨，没有显着的微观结构的演变，观察到在2keV及以下。比较了辐照后退火过程中的显微组织演变和退火过程中的气体脱附谱。钨在反辐照退火过程中，表面位错环发生逃逸。在热脱附光谱法过程中观察到的峰值温度与发生环逃逸的温度对应良好。这一事实表明，在环或附近的矩阵捕获的氢逃逸的表面与环一起。对高纯钨和低纯钨进行了比较。在低纯度钨中形成的环更稳定，抵抗滑动到表面。低纯度钨的氢保留率高于高纯度钨。因此，有必要研究高Z金属材料的制备工艺，即：e.用作面向等离子体材料杂质水平。

In-situ observations of microstructural evolution in molybdenum and tungsten were carried out during irradiation with low energy hydrogen ions for the purpose of investigating the effect of plasma-particle injection to plasma-facing components of fusion reactors. A strong dependence of microstructural evolution on the ion energy was observed in molybdenum. Loop generation, growth, tangling and the resulting network formation were observed with ions of 4ke V and above. On the other hand hydrogen clusters were observed at 2keV and below. In tungsten, however, no remarkable microstructural evolution was observed at 2keV and below. Comparisons were made between the microstructural evolution during post-irradiation annealing and gas desorption spectrometry during annealing. The escape of dislocation loops at the surfaces occuured in tungsten during the oppst-irradiation annealing. The peak temperature observed during the thermal desorption spectrometry corresponded well with that where the loop escape took place. This fact suggests that hydrogen trapped at the loops or nearby matrices escaped out of the surfaces together with the loops. The comparison was made between the high-purity and the low-purity tungsten. The loops formed in the low-purity tungsten were more stable, resistant against the slipping to the surfaces. The hudrogen retention was found to be high in the low purity tungsten relative to that in the high purity one. Thus it is needed to examine the high Z metallic materials considering their fabrication processes, i. e. impurity level for use as plasma-facing materials.