PREDNASAJUCI / LECTURER :

Mishal Nadeem

(1) Astronomical Institute, Slovak Academy of Sciences,
059 60 Tatranská Lomnica

NAZOV / TITLE :

Investigating Gamma Ray Attenuation Parameters of Epoxy-Fiber Cloth Composite Layers
Through Simulation and Experimentation

ABSTRAKT / ABSTRACT :

This study investigates the radiation shielding properties of novel lightweight hybrid composites
through a combination of simulation and experimental analysis. Simulations were carried out
using advanced tools such as WinXCom and Phy-X/PSD to evaluate key shielding parameters,
including the mass attenuation coefficient (MAC), linear attenuation coefficient (μ), half-value
layer (HVL), tenth-value layer (TVL), and mean free path (MFP). These were compared with
experimental results obtained using NaI (Tl) detectors and standard gamma-ray point sources
(⁶⁰Co, ¹³⁷Cs, and ¹³³Ba). The composites consisted of epoxy resin and WS₂, coated on Kevlar
fibers and fabricated using the manual lamination (hand lay-up) technique.

Three composite formulations with varying ratios of (C₂₁H₂₅ClO₅) and WS₂ were studied.
Experimental results demonstrated a decreasing trend in MAC with increasing photon energy,
indicating reduced interaction probability at higher energies. Among the tested samples, Sample
3; composed of 21% (C₁₄H₁₄N₂O₄), 71.1% (C₂₁H₂₅ClO₅), and 7.9% WS₂ at 1.2 mm thickness
showed the most promising shielding capability. Its MAC ranged from 0.096 cm²/g at 356 keV
to 0.050 cm²/g at 1332 keV, closely aligning with theoretical values (deviations from 3.91% to
16.32%).

A comparative analysis with lead revealed that while Pb maintains higher attenuation at lower
energies due to its high atomic number, the fabricated composites offer a significant advantage in
terms of reduced weight (composite density ~3.224 g/cm³ vs. lead's 11.34 g/cm³). These
findings emphasize the potential of WS₂-enhanced polymeric composites in applications
requiring efficient yet lightweight gamma radiation shielding. Despite some discrepancies

between simulated and experimental results which are mainly due to material thickness and low-
energy behavior; the results are encouraging. Further optimization and testing are recommended
to validate the long-term performance of these materials.

Keywords: Gamma Radiation, Lightweight Shielding, Composite Materials, WS₂, XCOM, Phy-
X/PSD, NaI Detector, Lead Alternative