A direct mathematical method to calculate the efficiency of bore hole cylindrical detectors

Several techniques can be used to determine the total efficiency,including monte carlo simulations,semi-empirical methods and experimental measurements. the first technique requires a good definition of the geometry and materials,including window thickness together with an accurate set of cross-sections. the second technique requires two different types of experimental input,the first being from use of sources emitting cascade γ-rays and the second from use of sources emitting isolated γ-rays in order to cover the wide energy range and provide coincidence-summing corrections,respectively. in the present method we introduce a theoretical approach based on the direct statistical method proposed by selim and abbas to calculate the total efficiencies for point,line and thin circular disk sources for scintillation detectors. the present method combines calculation of the path length covered by the photon inside the detector active volume and the geometrical solid angle ω,to obtain a straightforward mathematical expression for the efficiency calculation. by comparison,the total efficiency values are in good agreement with the theoretical calculations done by monte carlo simulation. © school of engineering,taylor’s university.