Development of real time measurement of dynamic hydrogen retention using spectroscopic method

建立了氘渗透通量实时测量系统。使用该系统，氘渗透通量的减少，观察到在氘等离子体辐照的钨样品的厚度为0.1毫米。这似乎是由于表面条件的修改。研究发现，在通入氢气和抽运氢气的条件下，具有280 nm钇膜和20 nm钯膜的钨样品的光反射率发生可逆变化。另外，拉伸方向垂直于表面的钨晶粒的氘保持率比平行拉伸的高2~10倍。这似乎归因于沿沿着晶界的有效扩散的差异。

Real-time measurement system of deuterium permeation flux has been built. Using this system, the decrease in the deuterium permeation flux was observed during deuterium plasma irradiation to the tungsten sample with the thickness of 0.1 mm. This seems to be attributed to modification of the surface condition. It is found that optical reflectivity of a tungsten sample with 280 nm yttrium film and 20 nm palladium film was reversibly changed when hydrogen gas was supplied and pumped. Moreover, it was revealed that deuterium retention of a tungsten sample with grains of which elongation direction was perpendicular to the surface was 2～10 times higher than that of parallel elongation. This seems to be attributed to difference in the effective diffusion along the grain boundary.