Comparison of efficiency calibration techniques of HPGe detector for radioactivity measurement of soil sample in Marinelli geometry

To keep the accredited category for the gamma spectrometry test in our laboratory, the efficiency curves of a HPGe detector for soil sample in Marinelli geometry were determined by “efficiency transfer” principle via the ANGLE3 commercial software and Monte Carlo simulations via MCNP5 and GEANT4. The efficiency obtained from experimental measurement of point standard sources was used as a reference efficiency curve for the input of ANGLE3 software as well as for correction of simulation codes of MCNP5 and GEANT4. The results of the efficiency for soil sample in Marinelli beaker obtained from the MCNP5 and GEANT4 were compared with the efficiency obtained from the ANGLE3 software. Moreover, the trueness of the detector efficiency obtained in this work was evaluated by the radioactivity measurement of 40 K, 137 Cs, 232 Th and 238 U in an IAEA reference material.