Penetration effects in scintiscanners collimators from gamma extended sources

Radiation penetration through the walls of wide-aperture conical hole collimators in the case of extended sources has been studied. Expressions are derived for the penetration fractions due to plane sources taking into consideration the diameter and effective thickness of the detector. The ray-tracing technique is used to calculate the triple integrals. The penetration fractions for varying source position are presented for different cases. (author)