title: Development of an optimized Compton suppression gamma-ray spectrometric system using Monte Carlo simulation.
abstract: We have chosen to establish the Compton Suppression Spectrometer (CSS) for low activity environmental samples with a high purity germanium (HPGe) primary detector and a removable plug-in detector (NaI(Tl)) surrounded with a cylindrical annulus guard detector (NaI(Tl)). Monte Carlo simulation with PENELOPE (PENetration and Energy LOss of Positrons and Electrons) is used to determine the optimal geometry of the CSS. To verify a correlation between experiment and simulation, the energy distribution of (137)Cs and (60)Co point sources is measured and simulated for each condition. The CSS parameters are studied to determine optimal detector geometry and Compton Suppression Factor (CSF). The timing resolution of the CSS was found to be 44ns (FWHM), which is an outstanding result in the semiconductor-based gamma-ray spectrometry. All measured values of CSF agree within 5% with the values obtained from the simulation. The optimum geometry and CSF values are discussed.
authors.affiliation: University of Science and Technology, Daejeon, Republic of Korea; Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Korea Research Institute of Standards and Science, Daejeon, Republic of Korea.
authors.forename: K B
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea. Electronic address: kjkim@kigam.re.kr.
authors.forename: K J
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: Korea Research Institute of Standards and Science, Daejeon, Republic of Korea.
authors.forename: J
authors.initials: J
authors.lastname: Han
authors.affiliation: Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea.
authors.forename: E S
authors.initials: ES
authors.lastname: Yi
keywords: Compton Suppression Factor; Compton Suppression System; Monte Carlo simulation; PENELOPE; Timing resolution