Gammastic: Towards a pseudo-gamma spectrometry in plastic scintillators
Résumé
War against CBRN-E threats needs to continuously develop sensors with improved detection efficiency. More particularly, this topic concerns the NR controls for homeland security. A first analysis requires indeed a fast gamma spectrometry so as to detect potential special nuclear materials (SNM). To this aim, plastic scintillators could represent the best alternative for the production of large-scale, low-cost radiation portal monitors to be deployed on boarders, tolls, etc. Although they are known to be highly sensitive to gamma rays, due to their poor resolution, information relative to the nature of the SNM is tricky. Thus, only the Compton edge is obtained after interaction, and no information of the photoelectric peak is observed.
This project concerns new developments on a possible pseudo-gamma spectrometry performed with plastic scintillators. This project is articulated on a combination of two developments: The design of new materials most suitable for recovering the photoelectric peak after gamma interaction with the scintillator. This work concerns mainly plastic scintillators loading with heavy elements, such as lead or bismuth. The analysis of the resulting signal with smart algorithms. This work is thus a pluridisciplinary work performed at CEA LIST and embeds 4 main disciplines: MCNPX simulations (simulated spectra), chemistry of materials (preparation of various plastic scintillators with different properties), instrumentation (lab experiments) and smart algorithms. Really impressive results were obtained with the unfolding of simulated spectra at various energies (from 241Am to 60Co) and an innovative approach was proposed to counter-balance the quenching effect of luminescence by heavy elements in plastic scintillators.
Mots clés
Plastics
Lead
Deconvolution
Nuclear measurements
Scintillation counters
Gamma-rays
Spectroscopy
Inference algorithms
Bismuth
gamma-ray spectroscopy
Monte Carlo
national security
nuclear materials safeguards
solid scintillation detectors
pseudogamma spectrometry
CBRN-E threats
chemical threats
biological threats
radiological threats
nuclear threats
high yield explosive threats
sensor detection efficiency
homeland security
fast gamma spectrometry
special nuclear material detection
large scale radiation portal monitors
low cost radiation portal monitors
Compton edge
photoelectric peak
scintillator-gamma interaction
lead loaded plastic scintillators
bismuth loaded plastic scintillators
MCNPX simulations
material chemistry
plastic scintillator preparation
241Am simulated spectra
60Co simulated spectra
luminescence
instrumentation
nuclear instrumentation
simulation
plastic scintillator
particle transport
Origine | Fichiers produits par l'(les) auteur(s) |
---|