tailieunhanh - Báo cáo " Studying of characteristic of GEM40P4 HPGE detector by experiment "

Radioactive sources which used to study were the standardized radioactive of common monoenergetic radionuclide Cs137 and standardized multigamma Co60, Ba133, Eu152. Determination of the absolute efficiency curve and energy resolution as a function of energy of GEM40P4 HPGe spectrometer are presented in this paper. | VNU Journal of Science Mathematics - Physics 25 2009 231-236 Studying of characteristic of GEM40P4 HPGE detector by experiment Bui Van Loat1 5 Nguyen Van Quan1 Le Tuan Anh1 Tran The Anh1 Nguyen The Nghia1 Nguyen Van Hung2 1 College of Sciences VNU 334 Nguyen Trai Thanh Xuan Hanoi Vietnam 2 Institute for Nuclear Research Dalat 01 Nguyen Tu Luc Dalat Vietnam. Received 1 November 2009 Abstract. Radioactive sources which used to study were the standardized radioactive of common monoenergetic radionuclide Cs137 and standardized multigamma Co60 Ba133 Eu152. Determination of the absolute efficiency curve and energy resolution as a function of energy of GEM40P4 HPGe spectrometer are presented in this paper. Keywords GEM40P4 HPGE detector relative efficiency absolute efficiency energy resolution. 1. Introduction The high purity germanium HPGe spectrometer is used for analysis of environmental sample and determination of radioisotope concentration due to its excellent resolution. This detector has better characteristics and more sensitive to the detection of impurities. When purchasing an HPGe detector operating characteristics such as resolution absolute efficiency were commonly used to compare different systems and to judge performance. . Absolute eficiency of HPGE detector As we known that the absolute efficiency of HPGe detector is the ratio of the number of counts in the full- energy photo-peak to the total number of gamma rays emitted from a source and can be determined by formula 1-4 N e E -N- 1 ABr . r where e E is the absolute detection efficiency at energy of E N is number of counts in the photo-peak net area A is activity of gamma source at measurement time Br is branching ratio corresponding to the energy of E and tr is denotes the real time taken for each successive measurement. In principal efficiencies of germanium detectors can be estimated from published measurements or calculations for detectors of similar size the accuracy of results based on these .