Validation of a method for computer calculation of germanium detector efficiencies
22 Jan 1994-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment (North-Holland)-Vol. 339, pp 87-91
TL;DR: In this article, the authors present a semi-empirational method for computing the peak efficiency of germanium detectors subject to validation, where the detector peak efficiency can be calculated on the basis of one experimentally determined efficiency for the same detector.
Abstract: This project was organized under the auspices of the International Committee for Radionuclide Metrology (ICRM) to demonstrate the validity of a method for computer calculations of germanium detector efficiencies. This computer method subject to validation is a simple semi-empirical method where the detector peak efficiency for any geometry can be calculated on the basis of one experimentally determined efficiency for the same detector. Seventeen laboratories participated with 26 different detectors and 25 volume sources, altogether 38 detector-beaker combinations. For most detectors, good agreement between experimental and calculated efficiencies was achieved in the energy interval 60–1800 keV. This project has proved that a major limitation for using this computer method is the insufficiency or inaccuracy in detector and detector housing dimensions. With accurate data available, the method should offer a simple and accurate way of calculating peak efficiencies for germanium detectors. The data collected for this project would also be useful for validating other efficiency calibration techniques.
Citations
More filters
21 Sep 2005-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, an implementation of the efficiency transfer method for cylindrical samples in gamma-ray spectrometry is presented, based on a Monte Carlo integration of the interaction probabilities of gamma rays over the detector and sample volumes.
Abstract: An implementation of the efficiency transfer method for cylindrical samples in gamma-ray spectrometry is presented, based on a Monte Carlo integration of the interaction probabilities of gamma rays over the detector and sample volumes. This approach makes it possible for the computer code to be relatively straightforward to write and the speed of the calculation to be adequate for routine on-line analysis of gamma-ray spectra. Virtual components of the detector system are introduced to prevent any erroneous or double counting of gamma-ray paths, which simplifies the tracking algorithm.
168 citations
11 Feb 2004-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the first attempt to use GEANT4 to model a reverse electrode germanium detector (REGe), and to improve also its efficiency calibration procedure, is presented, where a variance reduction algorithm based on a directional bias scheme is implemented into GEant4 in order to accelerate the efficiency computations.
Abstract: The GEANT4 software was developed by RD44, a world-wide collaboration of national institutes, laboratories and large High-Energy Physics experiments. GEANT4 is a public software package composed of tools which can be used to accurately simulate the passage of particles through matter. In this article, the first attempt to use GEANT4 to model a reverse electrode germanium detector (REGe), and to improve also its efficiency calibration procedure, is presented. A variance reduction algorithm based on a directional bias scheme is implemented into GEANT4 in order to accelerate the efficiency computations. A fast optimisation method to model the detector geometry using standard point sources is also presented and validated for point, Marinelli and air filter sources. The simulated full-energy peak efficiencies agreed with the measured values to within 1% between 36 and 1460 keV for these three counting geometries.
135 citations
01 Oct 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, Monte Carlo calculations were used to optimize the parameters of a 280 cm3 n-type Ge semiconductor photon detector with an accuracy of about 0.2% from 50 to 1400 keV.
Abstract: Precise measured data and an extensive set of Monte Carlo calculations have been combined to optimize the parameters for a 280 cm3 n-type Ge semiconductor photon detector, with the outcome that the Monte Carlo calculations now provide a very precise detector efficiency curve. The detector position and its length were determined from a set of measurements that included an axial scan. Measurements of the relative efficiencies based on radionuclides with accurately known relative photon emission rates were combined with efficiencies calculated by a Monte Carlo photon and electron transport code to adjust the detector diameter, internal deadlayer thickness, and the effective external deadlayer thickness. Our results show that, in a well-studied situation, it is possible to use Monte Carlo calculations to aid in the determination of a Ge detector's efficiency with an accuracy of about 0.2% from 50 to 1400 keV.
127 citations
21 Mar 2008-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: A detailed investigation of HPGe detector response for improved Monte Carlo efficiency calculations is presented in this article, where HPGe detectors are used for Monte-Carlo efficiency calculations and HPGe response is investigated.
Abstract: A detailed investigation of HPGe detector response for improved Monte Carlo efficiency calculations
116 citations
CERN1
21 Jul 2002-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The absolute efficiency of a high purity germanium (HPGe) detector was determined with a point-like calibrated 152 Eu source at two distances from the detector and three pure metallic thorium foils of different thicknesses.
Abstract: The absolute efficiency of a high purity germanium (HPGe) detector was determined with a point-like calibrated 152 Eu source at two distances from the detector and three pure metallic thorium foils of different thicknesses. The experimental values are compared with the ones determined with the simulation codes MCNP4B and GEANT 3.21. A procedure for HPGe absolute efficiency calibration is proposed for γ -ray energies higher than 200 keV.
42 citations
References
More filters
TL;DR: In this paper, a new technique is outlined for the calculation of the full energy peak efficiency of cylindrical gamma-detectors, including coaxial Ge(Li) detectors, and different source geometries are considered, i.e., point, disk and cylindrically shaped sources.
281 citations