Design of a portable HPGe detector: Performance characterization in identification of medical radioisotopes

This paper describes the methodology to model a hand-held high purity germanium detector (HPGe) and its performance characteristics. MCNPX was used to model the detector and conduct the study. The detection efficiency and the performance characteristics of the detector were studied over an energy range of 50–550 keV, that covers the energy range of medical isotopes used in nuclear medicine. More specifically, the performance was compared between two common medical isotopes: 99mTc and 131I. Detector efficiency was calculated for point sources, in air and tissue equivalent material. The maximum source distance at which the detector was able to capture a radiation signal was calculated.

► Modeling of a Micro Detector system, used in population monitoring and screening. ► Study of performance characteristic of MicDet system. ► Comparison of detector counting efficiency, among medical radionuclides.