환경시료의 방사능 측정에서 HPGe 검출기의 전에너지 피크효율 곡선에 관한 고찰

Abstract

Standard radioactive sources that are used in determining the efficiency of detectors used single nuclide standard radioactive sources that are composed of single gamma nuclides containing total energy area (60-1863keV), including environmental soil samples for environmental monitoring with a purpose of controlling radioactive. By measuring standard radioactive sources of diverse geometric shape of measuring containers (cylindricalMarinelli type: 40, 450 and 1000 ml) calculated full-energy peak efficiency of HPGe detectors, and compared this with full-energy peak efficiency of environmental sample soil. Spectrum was ready to measure gamma energy up to 3 MeV in 8192 (16384) channels with measuring time 20000 seconds. The detectors used in the experiments was from coaxial HPGe detectors of EG&G ORTEC. For 1332.5keV of gamma rays in 60Co, the energy resolving power is 1.8keV, relative efficiency 30%, and peak/Compton ratio 51/1. Furthermore,when apply to environmental samples, for high energy area (>1000 keV), it waswithin allowable error range of 4%, and the efficiency curves showed having uncertainties less than 4% within energy 60-1863keV. In addition to this, it was proven that it is effective in standard radioactive sources that are used in environmental monitoring around nuclear facilities. Thus it is considered that this might be highly effective in analyzing wide range of gamma spectrum including routine environmental sample measurement or in monitoring in case of emergency situation etc.