Characterization of the Radiation Contamination in an 18MV Linac Treatment Room Made of some Nanoparticles Mixture

Sara  Ghanavati; Nahid  Makiabadi; Sajad  Keshavarz; Hosein  Ghiasi

doi:10.18502/fbt.v10i4.13727

Sara Ghanavati Department of Medical Radiation Engineering, University of Science and Research Branch Tehran, Tehran, Iran
Nahid Makiabadi Department of Medical Radiation Engineering, University of Science and Research Branch Tehran, Tehran, Iran
Sajad Keshavarz Department of Medical Radiation Engineering, University of Science and Research Branch Tehran, Tehran, Iran
Hosein Ghiasi Medical Radiation Research Team, Tabriz University of Medical Sciences, Tabriz, Iran

DOI: https://doi.org/10.18502/fbt.v10i4.13727

Keywords: Monte Carlo; Neutron; N-XCOM; Dose Equivalent; Capture γ-Ray.

Abstract

Purpose: Shielding against radiation in radiotherapy and radiology requires deep knowledge of radiation physics and shielding design methods. The application of nanoparticles in the photon and neutron dose moderation has been proven in the literature.

Materials and Methods: Effective neutron mass removal cross-section (Σ_R/ρ) was for the ordinary concrete doped with 50nm in diameter nanosphers mixture of Fe₂O₃(5%), WO₃(5%), B₄H (5%), Pb₂O₃(5%) was estimated with MCNP5 Monte Carlo (MC) code and N-XCOM computational program. An 18MV linac room made of the nanoparticles dopped ordinarily simulated. Additionally, the room was considered with three legs in the maze and photoneutron and capture γ-ray Dose Equivalent (DE) were estimated at the modeled rooms maze.

Results: Total ΣR/ρ with energies 100 keV-2000keV was estimated using MC and N-XCOM as 0.02802-0.02687 cm²/gand 0.02810- 0.02687 cm²/g, respectively. Total ΣR/ρ of the neutron for the pure ordinary concrete was estimated by MC code and N-XCOM with energies 100 keV-2000keV as 0.02802-0.02687 cm²/g and 0.02810- 0.02687 cm²/g. Borated Polyethylene (BPE) and Lead required thickness calculated as 7.43×10^-06 mm and 4.73×10^-06 mm for the capture γ-ray shielding.