Nuclear Science and Techniques ›› 2019, Vol. 42 ›› Issue (2): 20402-020402.doi: 10.11889/j.0253-3219.2019.hjs.42.020402

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Efficiency calibration of electro-mechanical cooler for HPGe detector in a wide energy range

Weixu YUN1,2,Caijin XIAO1(),Yonggang YAO1,Junkai YANG1,Cong SHI1,2,Xudong LIU1,Chanjuan TANG1,Bangfa NI1,Fang FANG2   

  1. 1. Nuclear Physics Institute, China Institute of Atomic Energy, Beijing 102413, China
    2. Institute of Nuclear Technology and Automation, Chengdu University of Technology, Chengdu 610051, China
  • Received:2018-09-18 Revised:2018-12-29 Online:2019-02-10 Published:2019-02-19
  • Contact: Caijin XIAO E-mail:13811340271@139.com
  • About author:YUN Weixu, male, born in 1992, graduated from Changchun Institute of Technology in 2016, master student, focusing on nuclear resources and nuclear exploration engineering|YUN Weixu, male, born in 1992, graduated from Changchun Institute of Technology in 2016, master student, focusing on nuclear resources and nuclear exploration engineering|XIAO Caijin, E-mail:<email>13811340271@139.com</email>
  • Supported by:
    Supported by National Natural Science Foundation of China (No.11475266), CARR Reactor Base Project Construction Project (No.17ZYGC201401)

Abstract: Background

The prompt gamma neutron activation analysis involves a gamma ray efficiency scale of the high purity germanium (HPGe) detector in the 0.1~11 MeV wide energy region that can be used to calibrate the detection efficiency when the low energy standard source is unavailable.

Purpose

This paper aims to obtain the key technical indicators of HPGe detectors, to determine the relative efficiency curve under limited condition.

Methods

A 157Gd(n,γ) source was employed to replace low energy standard source. Combined with 35Cl(n,γ) cold neutron prompt source and 152Eu delayed source, efficiency grading was carried out by using both piecewise fitting and global fitting methods. The fitting effect of 157Gd(n,γ) source was compared with that of 152Eu source.

Results

The experimental results show that the calculation of integral global fitting is relatively simple, but the data obtained by piecewise fitting is more accurate and have better correlation, hence better result of piecewise fitting is achieved with comparison of global polynomial fitting. The use of the 157Gd(n,γ) source worked well without the low energy standard source such as 22Na, 54Mn, 133Ba, and the production efficiency calibration curve of HPGe detector was completed.

Conclusion

The piecewise logarithmic fitting method can be used to calibrate the detection efficiency of the all-energy peak in the wide-energy region of the electric refrigeration HPGe detector by using 157Gd(n,γ) source, which laid a solid foundation for future experiments such as neutron activation.

Key words: Wide energy efficiency calibration, Prompt gamma neutron activation analysis, Electro-mechanical cooler for high purity germanium detector

CLC Number: 

  • TL99