Evaluation of Neutron Spectra in the Linear Accelerator Facility of the Philippine General Hospital using an Indium-Based Multishell Neutron Spectrometer (In-MuNS)

Authors

  • Ma. Adela E. Arenas ⋅ PH College of Arts and Sciences, University of the Philippines Manila
  • Eric M. Inocencio ⋅ PH College of Arts and Sciences, University of the Philippines Manila, Philippines
  • Alvie J. Asuncion-Astronomo ⋅ PH Department of Science and Technology - Philippine Nuclear Research Institute, Philippines
  • Cheri Anne M. Dingle ⋅ PH Department of Science and Technology - Philippine Nuclear Research Institute, Philippines
  • Jeffrey D. Tare ⋅ PH Department of Science and Technology - Philippine Nuclear Research Institute, Philippines
  • Elrick T. Inocencio ⋅ PH University of the Philippines - Philippine General Hospital, Philippines

Abstract

The neutron energy spectra of the 10 megavolt linear accelerator at the Philippine General Hospital (PGH) were evaluated using an Indium-based Multi-shell Neutron Spectrometer (In-MuNS). Measurements were conducted by employing an indium foil central detector within several high-density polyethylene spherical shells irradiated under fixed conditions. Indium activation foils utilize the neutron detection reaction 115In(n,γ) 116mIn, emitting 116mIn gamma rays which were counted using a NaI(Tl) scintillation detector. Gamma spectrometry was then conducted to calculate the induced saturation activities. The Frascati Unfolding Interactive Tool (FRUIT) code, along with pre-validated In-MuNS response functions, were utilized to derive the neutron spectrum and ambient equivalent dose. The unfolding process revealed a total neutron fluence of 1.09×105 cm−2 Gy−1 at the isocenter, and 4.29×104 cm−2 Gy−1 at 70 cm away from the isocenter. The calculated ambient dose equivalent in air, H (10), at the two locations are 17.75 µSv/Gy and 5.60 µSv/Gy. The results can support local medical physicists in radiation protection against neutron contamination in LINAC facilities.

Issue

Article ID

SPP-2024-PF-09

Section

Poster Session F (Physics Education and Interdisciplinary Topics)

Published

2024-06-27

How to Cite

[1]
MAE Arenas, EM Inocencio, AJ Asuncion-Astronomo, CAM Dingle, JD Tare, and ET Inocencio, Evaluation of Neutron Spectra in the Linear Accelerator Facility of the Philippine General Hospital using an Indium-Based Multishell Neutron Spectrometer (In-MuNS), Proceedings of the Samahang Pisika ng Pilipinas 42, SPP-2024-PF-09 (2024). URL: https://proceedings.spp-online.org/article/view/SPP-2024-PF-09.