Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (12): 120201-120201.doi: 10.11889/j.0253-3219.2017.hjs.40.120201

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

Fast neutron radiation damage to NaI scintillator detector

YU Xiao1, YAN Siqi1,2, WEN Wanxin1,2, ZHANG Baoguo1,2, WANG Rensheng1,2, LIU Hanzhou1,2   

  1. 1 School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou 215123, China;
    2 Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
  • Received:2017-02-19 Revised:2017-03-16 Online:2017-12-10 Published:2017-12-08
  • Supported by:
    Supported by Major National Scientific Instruments Special Items (No.2013YQ04086102), National Natural Science Foundation of China (No.11605119), Natural Science Foundation of Jiangsu Province (No.BK20160304)

Abstract: Background: Prompt gamma neutron activation analysis (PGNAA) is an most important method to monitor the chemical compositions for bulk industrial materials. NaI detectors with large volume are often used for energy spectrum measurements of the prompt gamma rays in these cases. In the measurement, the NaI detectors are under a fast neutron field with large flux which is the primary factor of radiation damage to NaI crystal. Purpose: This study aims to estimate the lifetime of the NaI crystal in the PGNAA quantificationally, and investigate the energy resolution evolution for the NaI crystal caused by the fast neutrons damage. Methods: Based on the pulsed reactor CFBR-Ⅱ (China Fast Burst Reactor Ⅱ) in Chinese Academy of Engineering Physics (CAEP), two pieces of NaI crystal were irradiated with the fast neutron flux of 108 cm-2, 109 cm-2, 1010 cm-2, 1011 cm-2, 1012 cm-2, 1013 cm-2, 1014 cm-2, respectively. Meanwhile, the energy resolution was measured under each condition. Results: The energy resolution of NaI does not show obvious changes with the fast neutron irradiation flux upto 1014 cm-2. Conclusion: The energy resolution performance of NaI crystal does not deteriorate in fast neutron irradiation, except the strong neutron activation gamma rays. Therefore, to evaluate the lifetime of NaI crystal in a fast neutron field, a reliable lower limit can be figured out.

Key words: PGNAA, NaI, Fission neutron, Irradiation damage, Energy resolution

CLC Number: 

  • TL99