Mass attenuation coefficients, effective atomic numbers and electron densities of undoped and differently doped GaAs and InP crystals

The total mass attenuation coefficients (mu/rho), for GaAs, GaAs (semi-insulating; S-I) GaAs:Si (N+), GaAs:Zn, InP:Fe, InP:Fe-As, InP:S and InP:Zn crystals were measured at 22.1, 25.0, 59.5 and 88.0 keV photon energies. The samples were irradiated with Cd-109 and Am-241 radioactive point sources using transmission arrangement. The X- and gamma-rays were counted by a Si (Li) detector with resolution of 160 eV at 5.9 keV. Total atomic and electronic cross-sections (a, and a,), effective atomic numbers (Z(eff)) and electron densities (N-el) were determined using the obtained mu/rho values for the investigated crystals. (C) 2009 Elsevier Ltd. All rights reserved.