Vacuum system for SPring‐8 storage ring and test experience

We present the vacuum system design for the SPring‐8 storage ring and our experience with a series of its tests and R & D. We manufactured a leaf spring and slide guide as chamber mounts, and verified whether the chambers are distorted in any manner and return to their original locations even after each bake cycle or not. Deformation of a 4m‐long aluminum‐alloy chamber during evacuation and bakeout was also investigated. A bending magnet chamber was built by means of stretch forming. We evaluated the aluminum‐alloy flanges of various sizes. We investigated how many flanges reveal leakage in an experimental setup and what is the original of the leakage. We fanufactured all‐metal gate valve with RF contact. Its lifetime was investigated together with the leakage reliability at the seals. Bellows assembly was manufactured, and contact force together with contact resistance of the slide fingers was measured. The results in a variety of topics mentioned above will be described in detail.