Abstract
Japanese intense spallation neutron source (JSNS) driven by 3 GeV protons with power of 1 MW is constructed under joint project of Japan Atomic Energy Research Institute and High Energy Accelerator Research Organization. Super insulator is adopted to reduce heat load in hydrogen transfer line of JSNS. We performed irradiation test of super insulator (SI) using ^<60>Co gamma ray to evaluate the irradiation effect. Two kinds of super insulator (polyimide and polyester) coated both side by aluminum with thickness of 5×10^<-8>m were irradiated. After gamma ray irradiation, we performed tensile test and gas analysis of super insulator. Polyester based SI became brittle at about 10 MGy, on the other hand, polyimide based SI did not loss ductility even over 60 MGy. Polyester based SI generated about 30 times higher gas yield than that of polyimide based SI. However, it was very small amount of gas yield even polyester based SI. Gas analysis method by Q-mass was very effective to identify the unknown gas (i.e. H_2O) to compare with gas chromatography.
