Host: The Japan Society of Vacuum and Surface Science
As a method for reducing the outgassing from the inside of the vacuum material, high-temperature heat treatment under a high vacuum called vacuum firing has been known. The conditions for vacuum firing are 900°C for 2 hours for stainless steel at CERN and 850°C for 10 hours for titanium at the J-PARC, and so on. The reduction of hydrogen concentration in the material by vacuum firing has been reported by comparison with the non-vacuum firing material. On the other hand, there is no clear data, that shows the lower outgassing rate of the vacuum-fired material than that of non-vacuum-fired one. In this conference, we report the clear difference between them, which has been observed in the build-up test.
