Computational evaluation of a two-source neutron irradiator

Authors

Jayms Sagana ⋅ PH Department of Chemical, Biological, and Materials Engineering and Sciences, Mapúa University
Emerald Ramos ⋅ PH Department of Chemical, Biological, and Materials Engineering and Sciences, Mapúa University
Alvie Astronomo ⋅ PH Department of Science and Technology – Philippine Nuclear Research Institute
Cheri Anne Dingle ⋅ PH Department of Science and Technology – Philippine Nuclear Research Institute

Abstract

The Philippine Nuclear Research Institute (PNRI) is currently establishing the Neutron Irradiation Facility (NIF) which features two legacy plutonium beryllium (²³⁹PuBe) neutron sources with source strengths of 3.6×10⁶ n/s and 1.8×10⁶ n/s. In this paper, a PHITS (Particle and Heavy Ion Transport Code System) computational model was developed based on the existing MCNP (Monte Carlo N-Particle) LUNIS file provided by PNRI. The PHITS model was then used to optimize a configuration for NAA applications by maximizing the total fluence and its thermal neutron component. It was determined that the optimal thickness for the HDPE was 5.4 cm, providing the highest distribution of thermal neutron flux with minimal absorption by the moderator. At this thickness, a significant thermal neutron flux of 6.4×10³ n/cm²s is achieved, representing 58.24% of the total neutron flux. The configuration allows the maximum contribution of thermal neutrons while also maximizing the total number of neutrons in the irradiation location.

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Issue

2024: Proceedings of the 42nd Samahang Pisika ng Pilipinas Physics Conference

Article ID

SPP-2024-3B-03

Section

High Energy and Nuclear Physics

Published

2024-06-26

How to Cite

[1]

J Sagana, E Ramos, A Astronomo, and CA Dingle, Computational evaluation of a two-source neutron irradiator, Proceedings of the Samahang Pisika ng Pilipinas 42, SPP-2024-3B-03 (2024). URL: https://proceedings.spp-online.org/article/view/SPP-2024-3B-03.