Optimization of a Cryogenic System at Temperature 2K for the PKU-FEL Facility

The conceptual design of a cryogenic system at temperature 2K for the Peking University Free Electron Laser (PKU-FEL) facility is carried out. In order to minimize the scale of the cryogenic system and the running cost, the superconducting accelerator and the superconducting injector will mainly run at a long-pulsed mode. Optimization of the 2-K cryogenic system is carried out based on the heat load estimation and running parameters. Total cooling power of 52.5W for the long-pulsed mode is necessary for the PKU cryogenic system. The PKU cryogenic system will be the first 2-K system for accelerators in China and will provide experience for similar facilities.