Simplified efficiency calibration methods for semiconductor detectors used in criticality dosimetry.

"Oversimplified" and "simplified" methods based on true coincidence summing effect used in uncomplicated determination of the photo-peak efficiency of the semiconductor High Purity Germanium (HPGe) detector system are suggested and verified. The methods and calibrated Co radioactive source may be used to commission any HPGe detector to use during potential criticality event. The determined accuracy of the semiconductor HPGe detector system using this method is a few percent (for the detector system used in this study it was ≃8% for "oversimplified" and ≃5% for "simplified" methods accordingly) reasonable, expected, and good enough to use for estimation of neutron dose from irradiated human blood in a potential criticality event. Moreover, if one can experimentally deduce the photo-peak efficiency for Co 1333 keV γ-ray line using the suggested methods, then with a few percent accuracy this efficiency could be also used for 1369 keV γ-ray line in the decay of Na isotope.