Studies on mass attenuation coefficient, effective atomic number and electron density of some amino acids in the energy range 0.122–1.330 MeV

• Compute the Mass Attenuation Coefficient, effective atomic number and electron density of some amino acids.
• Gamma ray attenuation studies on biologically important molecules have been carried out using narrow beam good geometry set up.
• The values of Mass Attenuation Coefficient, effective atomic number and electron density of some amino acids are in agreement with the XCOM programme.
• The measured mass attenuation coefficient for some amino acids are useful in medical field.
• The data is useful in radiation dosimetry and other fields.

The total mass attenuation coefficients of some amino acids, such as Glycine (C2H5NO2), DL-Alanine (C3H7NO2), Proline (C5H9NO2), l-Leucine (C6H13NO2 ), l-Arginine (C6H14N4O2) and l-Arginine Monohydrochloride (C6H15ClN4O2), were measured at 122, 356, 511, 662, 1170, 1275 and 1330 keV photon energies using a well-collimated narrow beam good geometry set-up. The gamma rays were detected using NaI (Tl) scintillation detection system with a resolution of 10.2% at 662 keV. The attenuation coefficient data were then used to obtain the effective atomic numbers (Zeff) and effective electron densities (Neff) of amino acids. It was observed that the effective atomic number (Zeff) and effective electron densities (Neff) tend to be almost constant as a function of gamma-ray energy. The results show that, the experimental values of mass attenuation coefficients, effective atomic numbers and effective electron densities are in good agreement with the theoretical values with less than 1% error.