A comprehensive study on energy absorption and exposure buildup factors for some essential amino acids, fatty acids and carbohydrates in the energy range 0.015–15 MeV up to 40 mean free path

The gamma ray energy absorption (EABFEABF) and exposure buildup factors (EBFEBF) have been calculated for some essential amino acids, fatty acids and carbohydrates in the energy region 0.015–15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameter geometric progression (G-P) fitting approximation has been used to calculate both EABFEABF and EBFEBF. Variations of EABFEABF and EBFEBF with incident photon energy, penetration depth and weight fraction of elements have been studied. While the significant variations in EABFEABF and EBFEBF for amino acids and fatty acids have been observed at the intermediate energy region where Compton scattering is the main photon interaction process, the values of EABFEABF and EBFEBF appear to be almost the same for all carbohydrates in the continuous energy region. It has been observed that the fatty acids have the largest EABFEABF and EBFEBF at 0.08 and 0.1 MeV, respectively, whereas the maximum values of EABFEABF and EBFEBF have been observed for aminoacids and carbohydrates at 0.1 MeV. At the fixed energy of 1.5 MeV, the variation of EABFEABF with penetration depth appears to be independent of the variations in chemical composition of the amino acids, fatty acids and carbohydrates. Significant variations were also observed between EABFEABF and EBFEBF which may be due to the variations in chemical composition of the given materials.