Measurements of mass attenuation coefficient, effective atomic number and electron density of some amino acids

The mass attenuation coefficients of some amino acids, such as DL-aspartic acid-LR(C₄H₇NO₄), L-glutamine (C₄H₁₀N₂O₃), creatine monohydrate LR(C₄H₉N₃O₂H₂O), creatinine hydrochloride (C₄H₇N₃O·HCl) L-asparagine monohydrate(C₄H₉N₃O₂H₂O), L-methionine LR(C₅H₁₁NO₂S), 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 0.101785 at 662 keV. The attenuation coefficient data were then used to obtain the effective atomic numbers (Z_eff), and effective electron densities (N_eff) of amino acids. It was observed that the effective atomic number (Z_eff) and effective electron densities (N_eff) initially decrease and tend to be almost constant as a function of gamma-ray energy. Z_eff and N_eff experimental values showed good agreement with the theoretical values with less than 1% error for amino acids. - Highlights: • We report the values of mass attenuation coefficients (μ/ρ). • The values of (Z_eff) i.e. effective atomic number are calculated. • Measurement of effective electron density (N_eff) of some amino acids. • Comparison of all μ/ρ values with XCOM programme