Abstract

Mass attenuation coefficient (), effective atomic number () and effective electron density () were determined experimentally and theoretically for some amino acids (Glycine, L-Alanine, D-Alanine, Proline, L-Leucine and D-Leucine) at 8.04, 8.91, 13.37, 14.97, 17.44, 19.63, 22.10, 24.90, 30.82, 32.06, 35.40, 36.39, 37.26, 43.74, 44.48, 50.38, 51.70, 53.16, 80.99, 276.40, 302.85, 356.01, 383.85 and 661.66 keV photon energies by using an high-purity germanium (HPGe) detector with a resolution of 182 eV at 5.9 keV. The theoretical mass attenuation coefficients were estimated using mixture rule. The calculated values were compared with the experimental values for all amino acids. Good agreement has been observed between experimental and theoretical values within experimental uncertainties. The results show that mass attenuation coefficients, effective atomic numbers and effective electron densities depend on photon energy and chemical content. Also, the investigated parameters are different in different isomers (L- and D-) ofthe same molecule.

Key words: Mass attenuation coefficient, effective atomic number, effective electron density, high-purity germanium (HPGe) detector.