Broad beam Compton backscattering from cellulose triacetate and aluminium, theoretical analysis

Analysis is continued of previous results of broad beam Compton backscattering for γ-rays in the range 0.123-1.33 MeV, obtained as functions of area and thickness for cellulose triacetate and aluminum. This analysis uses a theoretical formalism in which the path difference between broad and parallel beams in the three dimensional case is taken into consideration. The areas used are 5 x 5, 7 x 7 and 10 x 10 cm2. A mathematical build-up correction term depending on the source-target and target-detector distances and on the γ-energy is derived. The variation of this term due to photon energy, area, thickness for aluminum, and cellulose triacetate targets is discussed with reference to the total and differential incoherent scattering cross sections. (author)