Nuclear Techniques ›› 2016, Vol. 39 ›› Issue (12): 120202-120202.doi: 10.11889/j.0253-3219.2016.hjs.39.120202

• LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS • Previous Articles     Next Articles

Methodology study on the sourceless efficiency calibration of airborne gamma-ray spectrometry

WU Hexi1,2,3, GE Liangquan3, WEI Qianglin2, YANG Bo2, LUO Yaoyao3, LIU Yibao1,2, YU Fei2   

  1. 1 Engineering Research Center of Nuclear Technology Application, Ministry of Education, East China University of Technology, Nanchang 330013, China;
    2 School of Nuclear Science and Engineering, East China University of Technology, Nanchang 330013, China;
    3 Chengdu University of Technology, Chengdu 610059, China
  • Received:2016-08-31 Revised:2016-09-19 Online:2016-12-10 Published:2016-12-10
  • Supported by:

    Supported by National Natural Science Foundation of China (No.11505027, No.11665001, No.41604116), Open-ended Foundation from Engineering Research Center of Nuclear Technology Application, Ministry of Education (No.HJSJYB2014-7&8)

Abstract:

Background: It is still difficult to establish all calibration models for significant short-lived artificial radionuclides because of the short half-life periods of most artificial radionuclides, potential radiation hazards, high cost, etc. Therefore, how to obtain more accurate quantitative results from airborne gamma-ray spectrum needs to be solved urgently. Purpose: This study aims to find a calculation model for efficiency calibration of airborne gamma-ray spectrometry (AGS). Methods: Based on the basic thought in calculus, tiny source is divided from gamma radiation on arbitrary shape by a grid partition method and seen as a point source. And the full-energy peak efficiency formula of AGS for a point source is derived in this paper. According to the superposition principle, the sourceless efficiency calibration method of AGS is established. Results: Firstly, the calculation values show an agreement within ±5% error in comparison with measurement values while a point source of 137Cs is only a short distance away. Secondly, the calculation response law of different positions by this paper coincides with the experiment of Grasty et al. Finally, the calculation values show an agreement within ±10% error in comparison with measurement values while a point source of 137Cs and 60Co is put under the AGS-863 for 5-100 m. These prove that the numerical calculation is suitable for computing the full-energy peak efficiency of a point source. Meanwhile, the calculation values of a surface source and a volume source show an agreement within ±1.5% error in comparison with simulation values by MCNP5. And while AGS is 90-150 m away from infinite volume source, the calculation values of 1 460.83 keV and 2 614.533 keV are 8.33%-15.82% bigger than the measurement values. Conclusion: These results verify that the sourceless efficiency calibration method of AGS is accurate and reliable. It gives technical support for monitoring radionuclide deposition after nuclear accidents and locating radioactive sources using AGS.

Key words: Airborne gamma-ray spectrometry, Sourceless efficiency calibration, Numerical calculation

CLC Number: 

  • TL817+.2