Simulation Study on the Moderator in PGNAA-Based Online Coal Measurement System

Abstract:

An online coal measurement system, which is based on the prompt gamma neutron activation analysis (PGNAA) technology and uses a D-T neutron generator, is studied in this work. To improve the analytical precision of the element in coal, the original moderator is optimized. The standards of the optimization are (1) the neutron flux increase 50% after moderation; (2) the proportion of thermal and middle-energy neutron and fast neutron is nearly equal to 1:1. Using Monte Carlo method, the moderator has been optimized by adding the uranium238 to the original moderator, which consists of high density polyethylene (HDPE). The simulation results show that the optimization standards can be basically satisfied when the thickness of the uranium238 and HDPE are 4cm and 1cm respectively. On this basis, preliminary study on introducing the channel to moderator is carried out. The preliminary results show that the channel can improve the total neutron flux. But also, it will decrease the proportion of thermal and middle-energy neutron and fast neutron.

• Periodical: Applied Mechanics and Materials (Volumes 675-677)
• Pages: 1316-1320
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.675-677.1316
• Online since: October 2014
• Authors: Qing Shan, Qun Li, Can Cheng, Wen Bao Jia*, Da Qian Hei, Yong Sheng Ling
• Keywords: D-T Neutron Generator, Moderator, PGNAA, Uranium238

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