Development of magnetic field measurement system for SHINE superconducting undulator

Abstract The Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE), under construction, will use 40 vacuums superconducting undulators (SCU) to generate linearly polarized free-electron lasers. Its magnetic field measurement system relies on the Hall probe method, featuring components like a Hall probe sledge, laser positioning, vacuum chambers, motion control, and data acquisition. At 4K, as the sledge moves, the system performs precise magnetic measurements. The paper discusses the magnetic field measurement system, the low-temperature calibration of the Hall probe and recent experimental data.