Mass attenuation coefficients and effective atomic numbers of biological compounds for gamma ray interactions

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2017-09, Vol.138, p.75-80
• Main Authors: Gaikwad, Dhammajyot Kundlik, Pawar, Pravina P., Selvam, T. Palani
• Format: Article
• Language: English
• Subjects: Amino acids; Atomic cross-section; Atomic properties; Attenuation coefficients; Beams (radiation); Biological effects; Collimation; Cross-sections; Effective atomic number and Effective electron density; Electron density; Electronic cross-section; Energy resolution; Enzymes; Fatty acids; Mass attenuation coefficient; Proteins; Studies
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2017.03.040

The mass attenuation coefficients (μ/ρ) for some enzymes, proteins, amino acids and fatty acids were measured at 122, 356, 511, 662, 1170, 1275 and 1330keV photon energies, by performing transmission experiments using 57Co, 133Ba, 137Cs, 60Co and 22Na sources collimated to produce 0.52cm diameter beams. A NaI (Tl) scintillation detector with energy resolution 8.2% at 663keV was used for detection. The experimental values of (μ/ρ) were then used to determine the atomic cross section (σa), electronic cross section (σe), effective atomic number (Zeff) and electron density (Neff). It was observed that (μ/ρ), σa and σe decrease initially and then tends to be almost constant at higher energies. Values of Zeff and Neff were observed roughly constant with energy. The deviations in experimental results of radiological parameters were believed to be affected by physical and chemical environments. Experimental results of radiological parameters were observed in good agreement with WinXCom values. •Mass attenuation coefficients of twelve biological compounds were measured.•Measured gamma rays energy is 122–1330keV.•The results of ε, σa, σe, Zeff, Neff were determined and compared with WinXCom.•Investigated results of organic compounds are useful for medical applications.