[1A07-11] Divertor and Superconducting Materials

[1A07] High Accurate Evaluation of Deuterium and Helium Behavior in Tungsten by STEM-EELS

*Kohei Sano¹, Tomoya Sawae¹, Mitsutaka Haruta², Hiroki Kurata², Mitsutaka Miyamoto¹ (1. Shimane Univ., 2. Kyoto Univ.)

Keywords:Nuclear fusion reactor, Gas retention characteristics, Helium bubble, deuterium, tungsten

It has been reported that the retention of deuterium (D) increases significantly in W pre-irradiated with helium (He), which is a major contributor to defect formation, and that He has a significant effect on the D retention behavior. However, although various studies have been conducted on the mechanism, no conclusive findings have yet been obtained. In this experiment, thin film samples were prepared after He pre-irradiation and D irradiation, and the presence and trap positions of D and He in W were quantitatively evaluated using a STEM-EELS at Kyoto University. The results suggest that most of D in W is trapped in He bubbles. In the presentation, the dependence on He pre-irradiation dose and sample temperature will also be discussed.