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

建立了氚渗透通量实时测量系统。利用该系统对厚度为0.1 mm的钨样品进行了氢等离子体辐照，观察到了氢的渗透通量的降低。这似乎归因于表面状况的改变。结果表明，当氢气供应和泵浦时，具有280 nm Y膜和20 nm Pd膜的钨样品的光学反射率发生了可逆的变化。此外，还发现拉伸方向垂直于表面的钨样品的氘保留率是平行拉伸的2~10倍。这似乎归因于沿晶界的有效扩散的不同。

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.