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Characterizing low-activity waste containers: A case study for Compton Suppression Systems under challenging signal-to-noise ratio
- Source :
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Elsevier, 2020, 949, pp.162806. ⟨10.1016/j.nima.2019.162806⟩, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2020, 949, pp.162806. ⟨10.1016/j.nima.2019.162806⟩
- Publication Year :
- 2020
- Publisher :
- HAL CCSD, 2020.
-
Abstract
- International audience; This work investigates a compact Compton Suppression System (CSS) based on a High-Purity Germanium (HPGe) diode as a primary spectrometer. From a wide range of potential materials for the guard detector, including plastic scintillator, Thallium doped Sodium Iodide (NaI(Tl)), and Lanthanum III bromide (LaBr3), a bismuth germanate crystal (BGO) is selected on account of a high photon mass-attenuation coefficient, thus allowing more compactness. The authors then describe the complete design study of an HPGe/BGO CSS based on the post-processing of Monte Carlo particle track history files (MCNP6.1/PTRAC). The calculation program, simulating the filtering of coincident events on both primary and secondary detectors, is validated through a series of experimental measurements using Am-241, Cs-137, and Co-60 sources in various configurations. On the basis of this empirically validated calculation, an optimization study of the BGO-active shield is performed over two factors of merit: Compton Suppression Factor (CSF) and Full-Energy Peak Efficiency. Optimization steps subsequently involve the scaling of BGO internal and external radii, the thickness of the entrance window, and the diameter of a collimation hole. Eventually, performance figures of the CSS are illustrated in a case study involving the characterization of large waste containers, carrying low levels of uranium activity to seek among natural radiological background. Calculation results show a lowering of minimal detectable activities (MDA) by a factor of 2.5 based on the signature of 1001-keV gamma rays from U-238.
- Subjects :
- Nuclear and High Energy Physics
Monte Carlo method
Radioactive waste containers
Active shielding
spectrum analysis
Scintillator
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
primary spectrometer
01 natural sciences
Bismuth germanate
plastic scintillator
030218 nuclear medicine & medical imaging
spectrometry
modelling
03 medical and health sciences
chemistry.chemical_compound
0302 clinical medicine
Optics
0103 physical sciences
[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]
signal processing
Monte Carlo
nuclear instrumentation
Physics
instrumentation
Spectrometer
detector
010308 nuclear & particles physics
business.industry
Detector
Compton Suppression System (CSS)
photon
Gamma ray
Particle transport
Primary activity measurement
gamma-rays
Gamma-ray spectrometry
simulation
Semiconductor detector
chemistry
Uranium
Full-Energy Peak Efficiency
Electronic anticoincidence
business
MCNP6
Subjects
Details
- Language :
- English
- ISSN :
- 01689002 and 18729576
- Database :
- OpenAIRE
- Journal :
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Elsevier, 2020, 949, pp.162806. ⟨10.1016/j.nima.2019.162806⟩, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2020, 949, pp.162806. ⟨10.1016/j.nima.2019.162806⟩
- Accession number :
- edsair.doi.dedup.....4c237cfccd6b755ef022c7ede79d1ad5