Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (7): 70101-070101.doi: 10.11889/j.0253-3219.2017.hjs.40.070101


Development of sub-cooled liquid nitrogen cooling system for CPMU

LIU Lijun1,2, WANG Shuhua1, WANG Jian1,2, LI Ming1, LIU Yiyong1, WANG Li1   

  1. 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Zhangjiang Campus, Shanghai 201204, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-03-22 Revised:2017-04-19 Online:2017-07-10 Published:2017-07-10
  • About author:10.11889/j.0253-3219.2017.hjs.40.070101
  • Supported by:
    Supported by National Natural Science Foundation of China (No.11172538)

Abstract: Background: The cryogenic permanent magnet undulator (CPMU) is one of the development trends of the insertion technology. The CPMU, made of NdFeB or PrFeB materials, has a better magnetic field performance at low temperature than that at room temperature. The operating temperature of the CPMU is in the range of 50-150 K up to the magnetic material to be adopted. The CPMU cooling system mainly consists of the CPMU sub-cooled liquid nitrogen cooling system and the CPMU magnet array cooling loop. Purpose: This study aims to develop the CPMU sub-cooled liquid nitrogen (SLN2) cooling system. Methods: According to the design scheme and design parameters of the first CPMU SLN2 cooling system for the Shanghai synchrotron radiation facility (SSRF), the heat loads of the system were calculated. The sub-cooled heat exchanger, one of the key components of the SLN2 system was designed. The flow resistance of the sub-cooled liquid nitrogen going through the whole CPMU cooling system was calculated, which provides the design base for liquid nitrogen recirculation pump.Results & Conclusion: The first CPMU, made of NdFeB material, and its SLN2 cooling system were installed at SSRF since August, 2016. Online test results showed that the SLN2 system met the CPMU cooling requirements and run stably.

Key words: CPMU, Sub-cooled liquid nitrogen cooling system, Sub-cooled heat exchanger, Flow resistance

CLC Number: 

  • TL503.91