Optimization of HEMA composition in polymer gel dosimeters for cost-effective radiation measurement

Muhammad Alhassan; Azhar Abdul Rahman; Iskandar Shahrim Mustafa

doi:10.61298/pnspsc.2026.3.327

Authors

Muhammad Alhassan
[email protected]

School of Physics, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia

Department of Physics, Federal University Dutsin-Ma, Katsina State, Nigeria
Azhar Abdul Rahman
School of Physics, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
Iskandar Shahrim Mustafa
School of Physics, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia

Keywords:

HEMA, Polymer Gel Dosimeter, Monomer Optimization, Tissue Equivalence, Radiological Properties

Abstract

Polymer gel dosimeters (PGDs) are potential tools for radiation measurement in radiotherapy treatment planning systems (TPSs) and nuclear energy monitoring. Optimization of monomer composition is an essential aspect of PGD formulation because it helps achieve optimal dosimetric performance. In this study, 2 hydroxyethyl methacrylate (HEMA), in combination with N,N'-methylene-bis-acrylamide (Bis), was optimized to improve dose-evaluation efficiency and cost-effectiveness. The results show that the HEMA-free formulation containing 2% (w/w) Bis had the lowest sensitivity. When Bis and HEMA were both added, sensitivity increased linearly with increasing total monomer percentage (%T). However, when the weight fraction (WF) of Bis was fixed and the co monomer percentage (%C) of HEMA increased from 0 to 60%, sensitivity decreased beyond the optimal value because of exhaustion of the vinyl groups in Bis. The mass density of the HEMA--Bis PGDs (≈ 1.04 g cm−3), their electron density (ρ_e = 3.42 × 10²³–3.43 × 10²³ cm⁻³), their number of electrons per unit mass (n_e = 3.28 × 10²³–3.30 × 10²³ g⁻¹), and their effective atomic number (Z_eff= 7.3624–7.4176) are comparable to those of water and muscle tissue, indicating water and tissue equivalence. These findings not only yield a more efficient HEMA-based PGD but also improve cost-effectiveness, thereby increasing affordability for healthcare applications.

Dimensions

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