Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (10): 100402-100402.doi: 10.11889/j.0253-3219.2017.hjs.40.100402


Locating radioactive source based on three coupled-crystals directional detector of γ rays

ZHANG Zhenchao, ZUO Guoping, TAN Junwen, ZHOU Yang, ZHANG Fan   

  1. School of Nuclear Science and Technology, University of South China, Hengyang 421001, China
  • Received:2017-03-21 Revised:2017-05-19 Online:2017-10-10 Published:2017-09-29
  • Supported by:
    Supported by Natural Science Foundation of Hunan Province (No.2016JJ2106)

Abstract: Background: With the increase application of radioactive sources, the possibility of radiation accidents is raised as well in recent years. Purpose: This study aims to fastly locate lost radioactive sources using a directional detector of γ rays. Methods: Three different coupled scintillators, i.e., NaI, CsI, Bi4Ge3O12 (BGO), together with center lead cylinder were employed to build the γ ray directional detection system. Localizing spatial radioactive source and the influences of angular resolution caused by lead-crystal ratio, rays energy and source dose rate were simulated by using MCNP (Monte Carlo N particle transport code). Results: The angle deviation is less than 0.99°, provided that the air absorbed dose rate of 137Cs source is not lower than 0.331 μGy·h-1. The average angle measurement deviation is 0.46° when the air absorbed dose rate of 60Co source is 0.586 μGy·h-1. The positioning deviation of 3.7×107 Bq 137Cs source at a distance of 7 m and height of 4 m is about 5%. Conclusion: The three-coupled-crystals directional detector of γ rays can be used to identify the direction of incident γ rays and locate the spatial position of unknown radioactive source with reasonable radiant intensity.

Key words: γ rays, Three-coupled-crystals, MCNP5, Source locating

CLC Number: 

  • TL99