Gamma-ray energy absorption buildup factors of gaseousmixtures; neon (95%) + argon (5%), argon (95%) + acetylene (5%),argon (95%) + methane (5%), argon (95%) + carbon dioxide (5%), methane(70%) + pentane (30%) and argon (90%) + methane (10%) were studiedby Geometrical Progression (G-P) fitting for the photon energy range0.015-15 MeV. It was found that the equivalent atomic number, Zeq ofthe gaseous mixtures sharply reduces after 1 MeV photon energy. TheZeq for the mixture of methane (70%) + pentane (30%)is the minimum, whereas the maximum is for argon (95%) + carbondioxide (5%) for the photon energies under investigation. The EnergyAbsorption Buildup Factor (EABF) for methane (70%) + pentane (30%)was found to be the highest among all the selected gaseous mixtures.The chemical composition of the gaseous mixtures has an impact onthe EABF values for photon energy and penetration depth. The investigationof the EABF is useful for selection of gaseous mixtures in designconsideration of gaseous radiation detectors for gamma radiation.
