Radiation Physics and Engineering
A peer-reviewed journal published by K. N. Toosi University of Technology

Computational investigation of the effect of polyethylene and aluminum sample thickness on neutron radiography using emulsion films‏

Articles in Press

Document Type : Research Article

Authors

Hamid Saebi
Zohreh Gholamzadeh
Pouneh Tayyebi

Nuclear Science and Technology Research Institute, Tehran, Iran

https://doi.org/10.22034/rpe.2026.583350.1360
Abstract
Neutron radiography is a non-destructive imaging technique used to study the internal structures of materials. In this work, a computational investigation was conducted to evaluate the effect of sample thickness on neutron radiography of polyethylene- and aluminum-based specimens using emulsion films. The MCNPX 2.7.0 code was employed to simulate the imaging geometry, including the sample, gadolinium converter, and emulsion film, for both polychromatic and monochromatic neutron beams. Sample thicknesses of 2, 4, and 6 cm were analyzed, and the contributions of neutrons and gamma rays to image formation were quantified through (n, γ) reaction rates and gamma deposited energy in the emulsion layer. Results show that increasing sample thickness reduces image quality, particularly for polyethylene due to its high thermal neutron scattering. Gamma-ray energy deposition was found to contribute to film exposure, particularly for thicker specimens, indicating that gamma radiation should be considered when interpreting emulsion-film neutron radiographs. The computational investigations showed that there are noticeable differences between the specimens' images formed by monochromatic and polychromatic neutron beams. These findings provide insights for optimizing imaging conditions, and detector selection in neutron radiography studies.

Highlights

  • Monte Carlo simulation of neutron radiography using emulsion films.
  • Polyethylene and aluminum samples were comparatively analyzed.
  • Image quality variations with sample thickness were evaluated.

Keywords

Neutron radiography
Gadolinium Converter
Emulsion film
Sample thickness
MCNPX
Subjects

Copyright
RPE is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).

Conflict of Interest
The authors declare no potential conflict of interest regarding the publication of this work‎.

Funding
‎The authors declare that no funds‎, ‎grants‎, ‎or other financial support were received during the preparation of this manuscript‎.

Radiation Physics and Engineering

Articles in Press, Accepted Manuscript
Available Online from 12 September 2026

  • Receive Date 26 May 2026
  • Revise Date 06 September 2026
  • Accept Date 11 September 2026

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