scholarly journals A Low Background Gamma Ray Spectrometer with Anticosmic Shielding

2016 ◽  
Vol 26 (1) ◽  
pp. 93
Author(s):  
Nguyen Quoc Hung ◽  
Vo Hong Hai ◽  
Tran Kim Tuyet ◽  
Ho Lai Tuan
Keyword(s):  
Nuclear Physics ◽  
Gamma Ray ◽  
Gamma Line ◽  
Background Suppression ◽  
Background Count ◽  
Background Count Rate ◽  
Low Background ◽  
Lead Shield ◽  
Gamma Ray Spectrometer ◽  
National University

The article describes a gamma ray spectrometer protected by a lead shield (Model 747E Canberra lead shield) and an active shield made of an 80~cm \(\times\) 80~cm \(\times\) 3~cm plastic scintillator plate in anticoincidence on top of the lead shield. The detector used as low background gamma-spectrometer is a high purity Germanium crystal of model GC2018 Canberra. The background count rate currently achieved (30-2400 keV) is 1.27 cps without anticoincidence. The level of background suppression obtained from the active protection is 0.80 overall and about 0.43 for the 511 keV gamma line. The gamma ray spectrometer is installed and operated in the Nuclear Laboratory, Department of Nuclear Physics, University of Science, HCMC-Vietnam National University.

scholarly journals Detection of background thermal neutrons in a modified low-background germanium gamma-ray spectrometer

2019 ◽  
Vol 322 (3) ◽  
pp. 1331-1339
Author(s):  
Jerzy W. Mietelski
Keyword(s):  
High Purity ◽  
Gamma Ray ◽  
Gamma Line ◽  
Thermal Neutrons ◽  
Cyclic Structure ◽  
Low Background ◽  
Gamma Ray Spectrometer ◽  
High Purity Germanium ◽  
Hpge Spectrometer ◽  
Water Moderator

Abstract The paper presents the detection of background neutrons using the 558.4 keV gamma line emitted from excited 114Cd nuclei after neutron induced processes. Stable cadmium and 60 L water moderator were placed inside low background shield of high purity germanium (HPGe) based spectrometer. The method was applied to study diurnal mean variation of background neutron flux. For this purpose 1 h gamma background spectra of modified HPGe spectrometer were collected subsequently for 50.5 days and then summed in 24-h-cycle. Results for the 558.4 keV line are presented along with those of main background lines. The total gamma-ray spectrum was also analysed and results are presented and discussed. No cyclic structure was noticed for all examited lines but 2223 keV, for which some day-night effect is suggested to exist. Test of another moderator made of 108 kg of graphite was done, but the results obtained with water are more promising.

scholarly journals Low-background, digital gamma-ray spectrometer with BEGe detector and active shield: commissioning, optimisation and software development

2019 ◽  
Vol 322 (3) ◽  
pp. 1311-1321
Author(s):  
Krzysztof Gorzkiewicz ◽  
Jerzy Wojciech Mietelski ◽  
Renata Kierepko ◽  
Kamil Brudecki
Keyword(s):  
Gamma Ray ◽  
Germanium Detector ◽  
Low Background ◽  
Gamma Ray Spectrometer ◽  
Annihilation Peak ◽  
The Mean ◽  
Plastic Scintillators ◽  
Set Up ◽  
Active Shield ◽  
Broad Energy

Abstract This paper presents results of the development process of low-background, digital gamma-rays spectrometer equipped with Broad Energy Germanium detector (CANBERRA BE5030), multi-layer passive shield and cosmic veto system that consists of five plastic scintillators (SCIONIX EJ-200). Data acquisition is performed using digitizer CAEN DT5725 with CoMPASS software. Output data analysis is carried out with purposely written and developed code VETO. On the basis of conducted tests, acquisition parameters were set up and tuned as well as time delays between all detectors were established. As a result of the configuration process, the mean background counts reduction of 64% in the whole spectrum and 65% in annihilation peak were achieved. This procedure allowed diminishing detection limits of selected isotopes 37% on average.

The Simulation of Low-Background Gamma Spectrometer With Clover Detector

2013 ◽  
Author(s):  
Huilan Liu ◽  
Yushou Song ◽  
Zhaoyang Xie ◽  
Baodong Sun
Keyword(s):  
Nuclear Physics ◽  
High Performance ◽  
Gamma Ray ◽  
Germanium Detector ◽  
Gamma Detector ◽  
Gamma Spectrometer ◽  
Radiation Level ◽  
Low Background ◽  
Clover Detector ◽  
Main Detector

A low-background gamma spectrometer consists of a high-performance gamma detector and a low-background chamber. It is widely used to monitor the radiation level of the environment and to identify the species of the radiological source. It is especially important for the analysis of the nuclear accident. Usually a high purity Germanium detector (HPGe) is used as a gamma ray detector. In order to enhance the detecting accuracy and sensitivity, it is essential to improve the performance of the gamma detector. In recent years, a clover detector composed of four coaxial HPGe crystals appear and is widely utilized in nuclear physics experimental research. Because of the larger dimensions and segmented structure, it displays outstanding characteristics different from traditional HPGe detectors. With a clover detector as the main detector and the HPLBS1 chamber of ORTEC as the lead chamber, the low-background gamma spectrometer is simulated by the Monte Carlo toolkit GEANT4, where the interaction processes of gamma ray provided by the GEANT4 physics list is used. The detecting performance of the low-background gamma spectrometer such as detecting efficiency and peak-total ratio are given. The results indicate that low-background gamma spectrometer with a clover as the main detector has better characteristic than that with HPGe as a main detector traditionally.

THE SIMULATION OF AN IMAGING GAMMA-RAY COMPTON BACKSCATTERING DEVICE USING GEANT4

2014 ◽  
Vol 27 ◽  
pp. 1460152
Author(s):  
D. FLECHAS ◽  
L.G. SARMIENTO ◽  
F. CRISTANCHO ◽  
E. FAJARDO
Keyword(s):  
Gamma Rays ◽  
Nuclear Physics ◽  
Gamma Ray ◽  
Structural Defects ◽  
Compton Camera ◽  
Experimental Conditions ◽  
Imaging Device ◽  
Compton Backscattering ◽  
National University ◽  
Simulated Images

A gamma-backscattering imaging device dubbed Compton Camera, developed at GSI (Darmstadt, Germany) and modified and studied at the Nuclear Physics Group of the National University of Colombia in Bogotá, uses the back-to-back emission of two gamma rays in the positron annihilation to construct a bidimensional image that represents the distribution of matter in the field-of-view of the camera. This imaging capability can be used in a host of different situations, for example, to identify and study deposition and structural defects, and to help locating concealed objects, to name just two cases. In order to increase the understanding of the response of the Compton Camera and, in particular, its image formation process, and to assist in the data analysis, a simulation of the camera was developed using the GEANT4 simulation toolkit. In this work, the images resulting from different experimental conditions are shown. The simulated images and their comparison with the experimental ones already suggest methods to improve the present experimental device

scholarly journals The characteristics of a low background germanium gamma ray spectrometer at China JinPing underground laboratory

2014 ◽  
Vol 91 ◽  
pp. 165-170 ◽  
Author(s):  
Zhi Zeng ◽  
Yuhao Mi ◽  
Hao Ma ◽  
Jianping Cheng ◽  
Jian Su ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Underground Laboratory ◽  
Low Background ◽  
Gamma Ray Spectrometer

scholarly journals Liquid Scintillation Counting in the London Underground

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 393-398 ◽  
Author(s):  
Sheridan Bowman
Keyword(s):  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
Gamma Ray ◽  
Scintillation Counting ◽  
Counting System ◽  
Background Count ◽  
Gamma Ray Spectrometer ◽  
London Underground ◽  
Below Ground ◽  
A Site

At the 12th International Radiocarbon Conference held in Trondheim, the potential of the London Underground as a site for liquid scintillation counting was considered (Bowman, 1986). This was discussed in light of a survey of three possible locations using a portable gamma-ray spectrometer. Two liquid scintillation counters, a Packard 3255 and an LKB “Kangaroo”, have now been successfully installed in a vault which is some 30m below ground. The reduction in background count rates achieved is discussed, together with other improvements made to the counting system.

scholarly journals Hiroshima University low-background .GAMMA.-ray spectrometer.

RADIOISOTOPES ◽  
1985 ◽  
Vol 34 (12) ◽  
pp. 682-685
Author(s):  
Kiyoshi SHIZUMA ◽  
Kazuo IWATANI ◽  
Hiromi HASAI
Keyword(s):  
Gamma Ray ◽  
Low Background ◽  
Gamma Ray Spectrometer
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