Nuclear Techniques ›› 2018, Vol. 41 ›› Issue (6): 60502-060502.doi: 10.11889/j.0253-3219.2018.hjs.41.060502


Measurement and analysis of the 232Th(n,2n) reaction rate in a polyethylene shell with DT neutrons

LIU Zhujun1,2, YANG Yiwei1, ZHENG Lei1,3, LIU Rong1, YANG Chaowen2, WANG Mei1   

  1. 1 Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China;
    2 Department of Nuclear Engineering and Technology, College of Physical Sciences and Technology, Sichuan University, Chengdu 610064, China;
    3 Department of Engineering Physics, Tsinghua University, Beijing 100084, China
  • Received:2018-02-05 Revised:2018-03-14 Online:2018-06-10 Published:2018-06-06
  • Supported by:
    Supported by National Natural Science Foundation of China (No.11505164), Presidential Foundation of China Academy of Engineering Physics (No.YZJJLX2016003), Neutron Key Laboratory Foundation (No.2015BA02)

Abstract: [Background] The 232Th(n,2n) reaction dominates the neutron generation, so the validity of the cross section data is significant in the thorium based reactor.[Purpose] In order to provide the data reference for the design of thorium based reactor, an integral experiment to measure the 232Th(n,2n) reaction rate was carried out using the activation method in a polyethylene shell with DT neutrons.[Methods] In the experiment, thorium samples were arranged in the 0° direction to the incident D+ beam, and a Au-Si surface barrier detector was used to monitor the neutron yield and the fluctuation of neutron flux.[Results] After irradiation, the 84.2 keV γ ray emitted from 231Th was measured by HPGe spectrometer, and the 232Th(n,2n) reaction rate was then obtained. The thorium sample was in foil and powder respectively to eliminate the effect of the sample condition. Simultaneously, the experiment was simulated precisely using Monte Carlo N Particle Transport Code (MCNP) code in the ENDF/B-Ⅶ.1, ENDF/B-Ⅶ.0, and JENDL4.0 libraries.[Conclusion] The calculated values in the JENDL4.0 were in good agreement with the experimental ones, which can provide reference for the design of thorium based reactors.

Key words: 232Th(n,2n) reaction rate, Neutron integral experiment, D-T neutrons, MCNP, Activation method

CLC Number: 

  • TL99