Effect on the full peak efficiency of HPGe detectors against different sample densities

The study aims to investigate the density effect on the full energy peak efficiency (FEPE) of five identical certified standard volume sources of the same geometry, radioisotopes, and activity but having different densities (0.7-1.6 g.cm-3) experimentally using a P-type HPGe detector of 100% relative efficiency and theoretically using ANGLE software. The count rate of γ-energy lines of the γ-sources 137Cs and 60Co were measured experimentally. Four methods were used to discuss the density effect of these sources on the full energy peak efficiency by showing the FEPE deviation percentages between the calculated and certified sample-specific activities. The methods showed that while ignoring the density of the source, the FEPE deviation percentages were very high , with an average of 14.025%. Considering the sources' density using either ANGLE-3 software or relative methods, the FEPE deviation percentages were very low, with acceptable averages of 2.13%.