Publications

Mattingly, John K.; Mitchell, Dean J.

Abstract not provided.

Mattingly, John K.; Mitchell, Dean J.; Stork, Chris L.

Abstract not provided.

Mattingly, John K.; Mitchell, Dean J.

Abstract not provided.

Mattingly, John K.; Mitchell, Dean J.; Harding, Lee T.; Varley, Eric S.; Hilton, Nathan R.

The primary function of the Gamma Detector Response and Analysis Software (GADRAS) is the solution of inverse radiation transport problems, by which the con-figuration of an unknown radiation source is inferred from one or more measured radia-tion signatures. GADRAS was originally developed for the analysis of gamma spec-trometry measurements. During fiscal years 2007 and 2008, GADRAS was augmented to implement the simultaneous analysis of neutron multiplicity measurements. This report describes the radiation transport methods developed to implement this new capability. This work was performed at the direction of the National Nuclear Security Administration's Office of Nonproliferation Research and Development. It was executed as an element of the Proliferation Detection Program's Simulation, Algorithm, and Modeling element. Acronyms BNL Brookhaven National Laboratory CSD Continuous Slowing-Down DU depleted uranium ENSDF Evaluated Nuclear Structure Data Files GADRAS Gamma Detector Response and Analysis Software HEU highly enriched uranium LANL Los Alamos National Laboratory LLNL Lawrence Livermore National Laboratory NA-22 Office of Nonproliferation Research and Development NNDC National Nuclear Data Center NNSA National Nuclear Security Administration ODE ordinary differential equation ONEDANT One-dimensional diffusion accelerated neutral particle transport ORNL Oak Ridge National Laboratory PARTISN Parallel time-dependent SN PDP Proliferation Detection Program RADSAT Radiation Scenario Analysis Toolkit RSICC Radiation Safety Information Computational Center SAM Simulation, Algorithms, and Modeling SNL Sandia National Laboratories SNM special nuclear material ToRI Table of Radioactive Isotopes URI uniform resource identifier XML Extensible Markup Language

Mitchell, Dean J.

The performance of the Advanced Synthetically Enhanced Detector Resolution Algorithm (ASEDRA) was evaluated by performing a blind test of 29 sets of gamma-ray spectra that were provided by DNDO. ASEDRA is a post-processing algorithm developed at the Florida Institute of Nuclear Detection and Security at the University of Florida (UF/FINDS) that extracts char-acteristic peaks in gamma-ray spectra. The QuickID algorithm, also developed at UF/FINDS, was then used to identify nuclides based on the characteristic peaks generated by ASEDRA that are inferred from the spectra. The ASEDRA/QuickID analysis results were evaluated with respect to the performance of the DHSIsotopeID algorithm, which is a mature analysis tool that is part of the Gamma Detector Response and Analysis Software (GADRAS). Data that were used for the blind test were intended to be challenging, and the radiation sources included thick shields around the radioactive materials as well as cargo containing naturally occurring radio-active materials, which masked emission from special nuclear materials and industrial isotopes. Evaluation of the analysis results with respect to the ground truth information (which was provided after the analyses were finalized) showed that neither ASEDRA/QuickID nor GADRAS could identify all of the radiation sources correctly. Overall, the purpose of this effort was primarily to evaluate ASEDRA, and GADRAS was used as a standard against which ASEDRA was compared. Although GADRAS was somewhat more accurate on average, the performance of ASEDRA exceeded that of GADRAS for some of the unknowns. The fact that GADRAS also failed to identify many of the radiation sources attests to the difficulty of analyzing the blind-test data that were used as a basis for the evaluation. This evaluation identified strengths and weaknesses of the two analysis approaches. The importance of good calibration data was also clear because the performance of both analysis methods was impeded by the inability to define the energy calibration accurately. Acronyms ACHIP adaptive chi-processed ASEDRA Advanced Synthetically Enhanced Detector Resolution Algorithm DNDO Domestic Nuclear Detection Office DRFs Detector Response Functions FINDS Florida Institute of Nuclear Detection and Security FWHM full-width half-maximum GADRAS Gamma Detector Response Analysis Software GUI graphical user interface HEU highly enriched uranium HPGe high purity germanium ID identification NaI Sodium iodide NNSA National Nuclear Security Administration NORM Naturally Occurring Radioactive Materials ppm parts per million SNL Sandia National Laboratories UF University of Florida WGPu weapons-grade plutonium

Mattingly, John K.; Mitchell, Dean J.

Abstract not provided.

Mitchell, Dean J.

Abstract not provided.

Mitchell, Dean J.; Tolk, Keith M.

Abstract not provided.