An alternative approach for the determination of the full-peak detection efficiency in case of a close-in detection geometry

The aim of this work is to propose an alternative method for the determination of εp in the case of measurements restricted to one single sample-detector distance. It is based on an iterative procedure, linking the measurement of calibrated multi-γ point sources at this particular detector distance (the resulting εp-function being disturbed by true-coincidence effects) with measurement of some coincidence-free single-γ point sources (leading to peak-to-total ratios P/T that, combined with detection efficiencies, yield correction factors for true-coincidence effects). The thus obtained εp versus Eγ curve for point-source geometry can then be converted to the actual extended sample geometry, based on the effective solid angle concept.