This paper presents the results of construction of relative and absolute efficiency functions within a range from 122 keV to MeV. The sources are used combining 152Eu point source and 36Cl activated isotope by thermal neutron captured reaction 35Cl of Dalat nuclear reactor (DNR) by 35Cl(n, γ) 36Cl reaction. This result can be applied in determining quantitative analysis of samples of neutron activation and radioactivity chemistry. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 18, SOÁ T2 - 2015 Determination of relative and absolute efficiency functions in the range of 122 keV ÷ MeV of HPGe detector • Nguyen An Son • Dang Lanh Da lat University • Trương Van Minh Dong Nai University (Received on April 6 th 2015, accepted on June 5 th 2015) ABSTRACT Construction of detector is necessary. However, on large energy range the manufacturers could not also support the explicit function of relative and absolute efficiencies of detectors. One of the reasons is a restriction of energy range of gamma sources (normally < 3 MeV). This paper presents the results of construction of relative and absolute efficiency functions within a range from 122 keV to MeV. The sources are used combining 152Eu point source and 36Cl activated isotope by thermal neutron captured reaction 35Cl of Dalat nuclear reactor (DNR) by 35Cl(n, γ)36Cl reaction. This result can be applied in determining quantitative analysis of samples of neutron activation and radioactivity chemistry. Keywords: Relative efficiency; absolute efficiency; prompt gamma; 35Cl(n, γ)36Cl reaction. INTRODUCTION In the experimental nuclear physics and radiation applications, the determination of relative and absolute efficiencies of spectrometry is necessary and research condition exactly. However, the construction of efficiency in large energy range is a restriction of energy range of gamma sources and method. In the previous papers, the authors used point sources of a radioisotope, so the absolute efficiency functions were < 3 MeV limited range [1,2,3]. There was also some simulated MCNP method for absolute efficiency functions in large energy range [4]. In this research, 152Eu point source was used to select photo peaks, which are 122 keV ÷ 1408 keV range, and use neutron activation analysis method. The 35Cl was activated on the 3rd channel of DNR, measuring prompt gamma by 35Cl(n, γ)36Cl reaction. The result was used to construct relative efficiency, .
