Studies on effective atomic numbers and electron densities of essential amino acids in the energy range 1 keV-100 GeV

The effective atomic numbers and electron densities of essential amino acids histidine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine have been calculated for total and partial photon interactions by the direct method in the wide energy range of 1 keV-100 GeV using WinXCOM. The values of these parameters have been found to change with energy and composition of the amino acids. The variations of effective atomic number and electron density with energy are shown graphically for all photon interactions. The variations of photon mass attenuation coefficients with energy are shown graphically only for total photon interaction. Dosimetric implication of mass attenuation coefficient in amino acids has also been discussed. (c) 2007 Elsevier B.V. All rights reserved.