Nuclear Techniques ›› 2014, Vol. 37 ›› Issue (01): 10101-010101.doi: 10.11889/j.0253-3219.2014.hjs.37.010101

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS •     Next Articles

Calibration of Hall probes at cryogenic temperature

ZHANG Wei WANG Shuhua ZHANG Jidong ZHONG Yi LIU Yiyong HE Yongzhou WANG Li ZHOU Qiaogen   

  1. (Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Zhangjiang Campus, Shanghai 201204, China)
  • Received:2013-11-04 Revised:2013-12-14 Online:2014-01-10 Published:2014-01-20

Abstract:

Background: The performance of permanent magnets at cryogenic temperature can be measured by using high-precision hall sensors. Purpose: Accurate calibration of high-precision hall sensor at cryogenic temperature is of great significance for the research on magnetic properties of cryogenic magnet. Methods: In Shanghai Synchrotron Radiation Facility (SSRF), we had the hall sensor placed at the helium temperature by using a cryo cooler based on the success of hall sensor calibration at room temperature. Several electric heaters mounted at the cold head are used to precisely adjust the test temperature (from 6.5 K to 300 K) and keep the temperature constant. The sensitivity of the Hall probes was measured at temperature range from 6.5 K to 300 K over a magnetic field range of ±1.8 T. Results: It was found that the sensitivity increased as the temperature decreased from 300 K to about 150 K and became flattened below 50K. The increase was 4% or so compared with the normal temperature sensitivity. Conclusion: The calibrated probe can be used to measure the performance of permanent magnet and meet the demand of permanent magnet property under low temperature environment.

Key words: Shanghai Synchrotron Radiation Facility (SSRF), Cryogenic Permanent Magnet Undulators (CPMU), Hall sensor, Calibration