Speaker
Description
The High Energy Photon Source (HEPS) is a 6 GeV synchrotron radiation light source equipped with a superconducting radio-frequency storage ring. Its seven SRF cryomodules operate at 4.5 K and are cooled by a helium cryoplant with a cooling capacity of 2.0 kW@4.5 K. Eleven cryogenic monochromators and six cryogenic permanent magnet undulators are installed onsite. A dedicated cryogenic system is developed to provide stable ultra-low-temperature operating conditions for HEPS.
The cryogenic system comprises helium and nitrogen cryoplants. The helium system supplies liquid helium for SRF cavities with a pressure stability of ±3 mbar and a liquid level stability of ±1%. The nitrogen system maintains the normal operation of 80K cryogenic devices. Customized automatic control strategies, optimized thermal insulation structures and cryogenic circulation loops are adopted to reduce heat loss and suppress cryogenic pressure fluctuations.
Field commissioning and operational results demonstrate that the system stably maintains the SRF cavities at 4.4 K, achieving a pressure stability better than ±3 mbar and a liquid level stability of ±1%, which fully meets the design targets. The LN₂ system operates continuously and reliably. With excellent adaptability and anti-interference capability, the cryogenic system can provide a valuable reference for the construction and operation of similar high-energy light source facilities.