Gamma-ray efficiency of a HPGe detector as a function of energy and geometry

The concept of double points detector model approach (DPDM) is developed as a procedure to find the full energy peak efficiency of the coaxial 120 cm3 closed hyperpure germanium (HPGe) detectors. Usually in the experimental nuclear physics work, which involves using HPGe detector for gamma-ray spectrometry, the full energy peak efficiency function must represent adequately the HPGe detector response. In the current work the gamma-ray energy in the range from 60 keV to 1332 keV and gamma-ray intensity changes by changing source to detector distance from 10 mm to 800 mm. The detector was characterized using a number of point-like standard sources. The calculated efficiencies obtained by (DPDM) are in good agreement with experimental data.