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Description
The storage ring vacuum system is a core component ensuring stable beam operation. Its primary function is to provide an ultra‑high‑vacuum environment with ultra‑low gas density for the beam, mitigate scattering losses induced by interactions between the beam and residual gas, and prolong beam lifetime.
The storage ring vacuum system mainly consists of Cr‑Zr‑Cu vacuum chambers, stainless‑steel vacuum chambers, bellows, various vacuum pumps (ion pumps, NEG pumps, etc.), cold cathode gauges and other components. The vacuum chambers adopt a small‑aperture design with an inner diameter of 22 mm and are fabricated from three types of materials, which imposes extremely stringent requirements on installation accuracy, sealing reliability and installation efficiency. Meanwhile, magnets are densely arranged inside the storage ring tunnel with limited operating space. Conventional installation tools and processes cannot meet the high‑precision installation requirements.
This paper systematically summarizes the technical practices for on‑site installation of the HEPS storage ring vacuum system. Aiming at the challenges encountered during installation, including multi‑cycle parallel installation, extremely confined space and stringent alignment accuracy requirements, a procedural installation process scheme is proposed.By optimizing the parallel workflow of three key procedures: vacuum chamber alignment, vacuum equipment installation and vacuum leak detection, developing multiple special non‑standard installation tools, and establishing standardized pre‑installation inspection and process‑control specifications, the efficient installation of vacuum equipment for the 1360.4 m beam line of the storage ring has been realized. After installation, following segmented baking and NEG‑film activation, the average static vacuum level outperforms the design specifications. It provides engineering experience for the on‑site installation of vacuum systems of comparable large‑scale scientific facilities.
