Characterization and dosimetric potential of C-series coumarin compounds for photon, proton, and neutron radiation types

Abstract This study explores the water-equivalent dosimetry potential of three novel coumarin compounds (C1, C2, and C3) for photon, neutron, and proton radiation applications, aiming to identify effective and practical alternatives to traditional dosimetric materials. The compounds were synthesized and structurally confirmed using IR, NMR, and UV–vis spectroscopy. Their water-equivalent properties were assessed using theoretical tools (NIST XCOM, SRIM, MRCsC, and EpiXS) as well as Monte Carlo simulations performed with GATE/Geant4. The comparative analysis of the results with established literature demonstrated distinct water-equivalency behaviors among the coumarin compounds. For photon interactions, S-series coumarins (particularly S3) exhibited the highest water equivalency, while compound C1 delivered the best overall performance compared to the C-series and conventional materials like PMMA and PC. Additionally, in proton dosimetry, C1 consistently maintained an excellent water-equivalent ratio (WER) of 1.069, demonstrating energy-independent behavior that simplifies clinical dose calculations. Overall, these results indicate that C1 is a strong candidate for high-energy proton beams, while S3 is ideally suited for photon applications. Coumarin-based materials also offer biocompatibility, fluorescence, and cost-effective synthesis, making them promising alternatives for next-generation phantom materials in dosimetry and radiation therapy.