Angular exposure build up factors for combined energy photons emitted from a line geometry radioactive source

In this paper, the angular exposure dose build up factor for combined photon energies of 6.13 and 7.12 MeV, emitted from a N-16 pipe radiator penetrating single layer shields of concrete and aluminium is calculated. Experimentally determined angular flux spectra were analysed. The angular exposure build up factor is defined for the combined energy source photons and the comparison with the values of angular build up factor for the same combined energy source of disc geometry is considered.