Magnetic field strength and temperature-dependent calibration system of Hall probe for the HEPS-TF cryogenic permanent magnet undulator

Purpose High energy photon source test facility (HEPS-TF) has manufactured a three-dimensional Hall probe to measure the cryogenic permanent magnet undulator (CPMU). Since the operating environment of the CPMU is the subcooled liquid nitrogen (85K), the temperature of the Hall probe will have a decrease of several degrees while carrying out the local magnetic measurement. We established a magnetic field strength and temperature-dependent calibration system to calibrate the Hall probe.