Abstract
One of the factors to make an ultra high vacuum apparatus is to reduce the gas permeation through the welded joint. In order to clarify the contribution of surface conditions and the diffusion in specimen, the hydrogen gas permeation through the stainless steel with variation in thickness is investigated. As a result, the significant difference is observed in the tendency of the gas permeation rate in transient process and the value of the permeation rate at the steady state. The results suggest the surface condition have the large effect to the gas permeation rate. The analysis of these results might lead to the clarification of the effect of the diffusion through the bulk material and the surface conditions to the gas permeation phenomena through the welded joint of the stainless steel.
