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Title: Generalized Multicoincidence Analysis Methods

Abstract

The ability to conduct automated trace radionuclide analysis at or near the sample collection point would provide a valuable tool for emergency response, environmental monitoring, and verification of treaties and agreements. Pacific Northwest National Laboratory is developing systems for this purpose based on dual gamma-ray spectrometers, e.g. NaI(TI) or HPGe, combined with thin organic scintillator sensors to detect light charged particles. Translating the coincident signatures recorded by these systems, which include beta-gamma, gamma-gamma and beta-gamma-gamma, into the concentration of detectable radionuclides in the sample requires generalized multicoincidence analysis tools. The development and validation of the Coincidence Lookup Library, which currently contains the probabilities of single and coincidence signatures from more than 420 isotopes, is described. Also discussed is a method to calculate the probability of observing a coincidence signature which incorporates true coincidence summing effects. These effects are particularly important for high-geometric-efficiency detection systems. Finally, a process for verifying the integrated analysis software package is demonstrated using GEANT 4 simulations of the prototype detector systems.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
881928
Report Number(s):
PNNL-SA-43563
Journal ID: ISSN 0018-9499; IETNAE; NN2001000; TRN: US0603039
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Nuclear Science, 53(1 PT 2):351-355; Journal Volume: 53; Journal Issue: 1 PT 2
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CHARGED PARTICLES; DETECTION; MONITORING; PHOSPHORS; PROBABILITY; RADIOISOTOPES; SPECTROMETERS; TREATIES; VALIDATION; VERIFICATION; multicoincidence analysis trace radionuclide analysis

Citation Formats

Warren, Glen A., Smith, Leon E., Aalseth, Craig E., Ellis, J. E., Valsan, Andrei B., and Mengesha, Wondwosen. Generalized Multicoincidence Analysis Methods. United States: N. p., 2006. Web. doi:10.1109/TNS.2006.869840.
Warren, Glen A., Smith, Leon E., Aalseth, Craig E., Ellis, J. E., Valsan, Andrei B., & Mengesha, Wondwosen. Generalized Multicoincidence Analysis Methods. United States. doi:10.1109/TNS.2006.869840.
Warren, Glen A., Smith, Leon E., Aalseth, Craig E., Ellis, J. E., Valsan, Andrei B., and Mengesha, Wondwosen. Wed . "Generalized Multicoincidence Analysis Methods". United States. doi:10.1109/TNS.2006.869840.
@article{osti_881928,
title = {Generalized Multicoincidence Analysis Methods},
author = {Warren, Glen A. and Smith, Leon E. and Aalseth, Craig E. and Ellis, J. E. and Valsan, Andrei B. and Mengesha, Wondwosen},
abstractNote = {The ability to conduct automated trace radionuclide analysis at or near the sample collection point would provide a valuable tool for emergency response, environmental monitoring, and verification of treaties and agreements. Pacific Northwest National Laboratory is developing systems for this purpose based on dual gamma-ray spectrometers, e.g. NaI(TI) or HPGe, combined with thin organic scintillator sensors to detect light charged particles. Translating the coincident signatures recorded by these systems, which include beta-gamma, gamma-gamma and beta-gamma-gamma, into the concentration of detectable radionuclides in the sample requires generalized multicoincidence analysis tools. The development and validation of the Coincidence Lookup Library, which currently contains the probabilities of single and coincidence signatures from more than 420 isotopes, is described. Also discussed is a method to calculate the probability of observing a coincidence signature which incorporates true coincidence summing effects. These effects are particularly important for high-geometric-efficiency detection systems. Finally, a process for verifying the integrated analysis software package is demonstrated using GEANT 4 simulations of the prototype detector systems.},
doi = {10.1109/TNS.2006.869840},
journal = {IEEE Transactions on Nuclear Science, 53(1 PT 2):351-355},
number = 1 PT 2,
volume = 53,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2006},
month = {Wed Feb 01 00:00:00 EST 2006}
}
  • The ability to conduct automated trace radionuclide analysis at or near the sample collection point would provide a valuable tool for emergency response, nuclear forensics and environmental monitoring. Pacific Northwest National Laboratory is developing systems for this purpose based on dual gamma-ray spectrometers, e.g. NaI(TI) or HPGe, combined with thin organic scintillator sensors to detect light charged particles. Translating the coincident signatures recorded by these systems, which include , and , into the concentration of detectable radionuclides in the sample requires generalized multicoincidence analysis tools. The development and validation of the Coincidence Lookup Library, which currently contains the probabilities ofmore » single and coincidence signatures from more than 420 isotopes, is described. Also discussed is a method to calculate the probability of observing a coincidence signature which incorporates true coincidence summing effects. These effects are particularly important for high-geometric-efficiency detection systems. Finally, a process for validating the integrated analysis software package is demonstrated using GEANT 4 simulations of the prototype detector systems.« less
  • Multicoincidence radionuclide analysis systems consisting of light-charged-particle detectors operating in coincidence with photon spectrometers are being developed to improve the sensitivity of radionuclide analysis in field applications. Requiring charged-particle/photon coincidence provides active shielding from environmental photon sources, and mapping photon-photon events into a coincidence plane can remove photon spectroscopy interferences. List-mode data acquisition and flexible hardware design ensures that the most sensitive coincidence schemes involving beta, atomic electron, gamma and x-ray emissions can be used for radionuclide quantification. System hardware design and preliminary measurement data are discussed. A centerpiece component of this project, the development of analysis tools and datamore » libraries required to perform automated multicoincidence analysis, is also described.« less
  • The sensitivity and uncertainty analysis tools of the ORNL SCALE nuclear modeling and simulation code system that have been developed over the last decade have proven indispensable for numerous application and design studies for nuclear criticality safety and reactor physics. SCALE contains tools for analyzing the uncertainty in the eigenvalue of critical systems, but cannot quantify uncertainty in important neutronic parameters such as multigroup cross sections, fuel fission rates, activation rates, and neutron fluence rates with realistic three-dimensional Monte Carlo simulations. A more complete understanding of the sources of uncertainty in these design-limiting parameters could lead to improvements in processmore » optimization, reactor safety, and help inform regulators when setting operational safety margins. A novel approach for calculating eigenvalue sensitivity coefficients, known as the CLUTCH method, was recently explored as academic research and has been found to accurately and rapidly calculate sensitivity coefficients in criticality safety applications. The work presented here describes a new method, known as the GEAR-MC method, which extends the CLUTCH theory for calculating eigenvalue sensitivity coefficients to enable sensitivity coefficient calculations and uncertainty analysis for a generalized set of neutronic responses using high-fidelity continuous-energy Monte Carlo calculations. Here, several criticality safety systems were examined to demonstrate proof of principle for the GEAR-MC method, and GEAR-MC was seen to produce response sensitivity coefficients that agreed well with reference direct perturbation sensitivity coefficients.« less
  • No abstract prepared.
  • Targets of /sup 12/C and /sup 27/Al have been bombarded by 35 MeV/nucleon /sup 20/Ne ions. Inside a cone of +- 10/sup 0/ around the beam axis, outgoing protons and ..cap alpha.. particles were detected by an arrangement of 18 scintillators in coincidence with particles of charge Z = 5--11 emerging at 2/sup 0/. At this energy the identified reaction mechanisms differ significantly from the ones observed in the 10--15 MeV/nucleon region. Important energy transfer of around 50 MeV to the target-like residues is observed. For the coincident oxygen-..cap alpha.. events, in addition to the well-known sequential decay mechanism ofmore » the projectile, about 40% of the events are attributed to another mechanism producing oxygen ions narrowly peaked near the beam velocity. Among the other reaction channels, cases are present which can be interpreted in terms of sequential decay alone, as well as others where admixtures of different processes play a role.« less