Gamma-ray buildup factors study for deep penetration in some silicates

The gamma ray buildup factors for six silicate samples have been calculated, in the energy range of 0.015–15 MeV for penetration depths up to 100 mfp (mean free path), using five parameters based geometric progression (G-P) fitting formula with modified expression for dose multiplication factor [K(E, x)]. The computations were done using ANSI/ANS 6.4.3-1991 (American National Standard). The extrapolation to the buildup factors of the selected samples beyond 40 mfp and up to 100 mfp in this energy range are new to the available literature. Calculated buildup factors of water have been shown good agreement with the available standard data. The obtained results for all samples have been compared and verified by using WinXCom software and GEANT4 Monte Carlo simulations.

► The G-P fitting method can be used to calculate buildup factors up to100 mfp.
► Radioactive waste safe disposal in deep soil or water can be assessed easily.
► (μ/ρ)Total Calculated by WinXCom and GEANT4 show good agreement.
► ANSI/ANS 6.4.3standards reaffirmed soon after suitable modifications.
► The G-P fitting method is the fastest method for buildup factor calculations.