Hydrogen retention in deposition layers formed from type 316 stainless steel

From the viewpoints of plasma control and radiation safety, tritium retention in deposition layers is an important problem. In this study, deposition layers from type 316 stainless steel were formed by a sputtering method using hydrogen RF plasma at three different temperatures. The behavior of hydrogen release from the deposition layers was observed by a thermal desorption method at argon atmosphere. It was found that hydrogen retention and release behavior greatly change depending on the temperature of a substrate where the layer is formed. The surface structure of the layer also changed depending on the temperature. However, the ratios of metallic atoms such as Fe, Cr and Ni in deposition layers were almost the same as that in type 316 stainless steel. (authors)