The Vacuum System of Large Heavy-Ion Accelerator Facility and Its Challenges

The Institute of Modern Physics,Chinese Academy of Sciences has accumulated experiences in the design of large-scale vacuum chambers, ultra-high/extremely high vacuum systems and heavy ion accelerator vacuum systems from the construction of large scientific facilities. In order to obtain the ultra-high/extremely high vacuum system, a complete technological process has been formed about the selection of vacuum acquisition equipment, material processing, sealing form and in-situ baking; In the development of the heavy ion accelerator facility(HIAF), a new method of ceramic-lined thin-walled vacuum chamber was proposed and a principle prototype was developed to reduce the gap of the magnet and greatly reduce the cost of the magnet and the power supply; the research of vacuum material desorption yield was carried out and the beam collimators were designed to effectively control the dynamic vacuum effect in the future operation of HIAF; the self-weight sealing structure was proposed and the pillow-seal flange was developed to solve the maintenance problem of the vacuum system in the high-radioactive area; the cryogenic vacuum system was carried out to improve the vacuum system of Spectrometer Ring.