A Hall Probe Calibration System at Low Temperature for the TPS Cryogenic Permanent Magnet Undulator

• Published in: IEEE transactions on applied superconductivity 2018-04, Vol.28 (3), p.1-5
• Main Authors: Chin-Kang Yang, Wen-Hsuan Hsieh, Yun-Liang Chu, Chang, C. H., Cheng-Ying Kuo, Sei-Da Chen, Jui-Che Huang, Ching-Shiang Hwang
• Format: Article
• Language: English
• Subjects: Calibration; cryogenic permanent-magnet undulator; Hall-probe calibration; Low temperature; Magnetic field measurement; magnetic field measurements in vacuum; Magnetic fields; Probes; Superconducting magnets; Temperature measurement; Temperature sensors
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2018.2795575

A cryogenic permanent-magnet undulator (CPMU) with a 15-mm period length is being constructed for the TPS. Field measurements of this undulator will be performed with a Hall probe at cryogenic temperatures, for which a field strength and temperature-dependent calibration system is necessary. This system consists of a cryo-cooler and a heater to control the Hall probe temperature, a home-made dipole electromagnet, a nuclear magnetic resonant Tesla meter, and two angle adjusting stages. These stages will rotate the Hall probe to adjust the angular accuracy of the Hall probe axes with respect to a reference ceramic surface and to measure the planar Hall effect coefficient. A two-axis compact 0.9-mm SENIS Hall probe is used in the very small gap of 4 mm of this CPMU. Design details and performance of this system, its calibrating process, and calibration results at various temperatures will be discussed in this paper.