Calculated absolute full-energy peak efficiencies for true coaxial Ge(Li) detectors in the photon energy region 0.1–3.0 MeV with different source-to-detector geometries

Absolute full-energy peak efficiencies, i.e. the ratio of the number of counts under the full-energy peak (FEP) to the number of photons at the same energy emitted by the source, are calculated for three true coaxial Ge(Li) detectors of differing size in the photon energy region 0.1–3.0 MeV. The detector volumes are 28.9, 82.1 and 144.9 cm³. Three different source-to-detector geometries are considered, namely a point source, a needle-shaped source and an extended volume source. The attenuation effects in the sources, the aluminium windows of the detectors and the p-cores of the detectors are taken into account. Three different media are considered in the extended sources.