Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2017, Vol. 28 ›› Issue (5): 61 doi: 10.1007/s41365-017-0213-z

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

Optimization of moderator assembly for neutron flux measurement: experimental and theoretical approaches

Abdul Waheed1•Nawab Ali2•Muzahir A. Baloch3•Aziz A. Qureshi1•Eid A. Munem4•Muhammad Usman Rajput2•Tauseef Jamal5•Wazir Muhammad6   

  1. 1 Radiation Physics Laboratory, Physics Department COMSATS Institute of Information Technology (CIIT)Islamabad Pakistan
    2 Physics DivisionPakistan Institute of Nuclear Science and Technology (PINSTECH)Islamabad Pakistan
    3 Department of Physics, College of Science Majmaah University Al-ZulfiSaudi Arabia
    4 School of Physics University Science Malaysia Gelugor Malaysia
    5 DCISPakistan Institute Engineering and Applied Sciences (PIEAS)Islamabad Pakistan
    6 Health Physics Division (HPD)Pakistan Institute of Nuclear Science and Technology (PINSTECH) Islamabad Pakistan
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Abdul Waheed, Nawab Ali, Muzahir A. Baloch, Aziz A. Qureshi, Eid A. Munem, Muhammad Usman Rajput, Tauseef Jamal, Wazir Muhammad. Optimization of moderator assembly for neutron flux measurement: experimental and theoretical approaches.Nuclear Science and Techniques, 2017, 28(5): 61     doi: 10.1007/s41365-017-0213-z


A moderator of paraffin wax assembly has been demonstrated where its thickness can be optimized to thermalize fast neutrons. The assembly is used for measuring fast neutron flux of a neutron probe at different neutron energies, using BF3 (Φ1" and Φ2") and 3He (Φ0.5") neutron detectors. The paraffin wax thickness was optimized at 6 cm for the neutron probe which contains an Am–Be neutron source. The experimental data are compared with Monte Carlo simulation results using MCNP5 version 1.4. Neutron flux comparison and neutron activation techniques are used for measuring neutron flux of the neutron probe to validate the optimum paraffin moderator thickness in the assembly. The neutron fluxes are measured at (1.17 ± 0.09) x 105 and (1.19 ± 0.1) x 105 n/s, being
in agreement with the simulated values. The moderator assembly can easily be utilized for essential requirements of neutron flux measurements.

Key words: Am–Be and 252Cf neutron sources, BF3 &, 3He detectors, Paraffin wax, Neutron flux, Monte Carlo simulation