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Wright, Michael C.

Publications and source records attributed to Wright, Michael C..

7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Initial Investigation of the Small Feature Detection Capability of the ORNL Fast Neutron Tomographic Imaging System

A variety of fast neutron imaging simulations and measurements were performed to investigate the spatial resolution and small feature detection capability of a fast-neutron tomographic imaging system developed at Oak Ridge National Laboratory. The system uses an associated particle DT (deuterium-tritium) neutron generator as the source and 25 mm × 25 mm × 100 mm plastic scintillators as the neutron detectors. Two image quality indicators were examined: 1) a variety of long steel pins embedded axially in the interior of a polyethylene cylinder and 2) a variety of short steels pins embedded radially in the surface of a shielded polyethylene cylinder. Measurements demonstrated detectability down to approximately 3 mm. Further data analysis may show improved detection performance and allow a more precise determination of the spatial resolution and small feature detection limit. The current DT generator has a neutron production spot size of about 3.5 mm, which appears to be the limiting factor in the current system configuration.

Wright, Michael C.↗
DOE OSTI2018

Initial Investigation of the Small Feature Detection Capability of the ORNL Fast Neutron Tomographic Imaging System

A variety of fast neutron imaging simulations and measurements were performed to investigate the spatial resolution and small feature detection capability of a version of the Oak Ridge National Laboratory fast neutron tomographic imaging system. Two image quality indicators were examined: (1) a variety of long steel pins embedded axially in the interior of a polyethylene cylinder, and (2) a variety of short steels pins embedded radially in the surface of a polyethylene cylinder. Measurements demonstrated detectability of about 3 mm. Further data analysis may show improved detection performance and allow a more precise determination of the spatial resolution. Our current simulation code takes only partial consideration of the DT generator neutron production spot size, with neutron production effectively originating at a single point. Simulations showed that features less than 2 mm should be detectable with an improved generator. Our current ING-27 DT generator has a neutron production spot size of about 3.5 mm, which appears to be the limiting factor at present. Generators with spot sizes as small as 1 mm are commercially available. Higher-power, small–spot size associated particle generators are at the prototype stage and are expected to be commercially available soon.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Transportable, Low-Dose Active Fast-Neutron Imaging

This document contains a description of the method of transportable, low-dose active fast-neutron imaging as developed by ORNL. The discussion begins with the technique and instrumentation and continues with the image reconstruction and analysis. The analysis discussion includes an example of how a gap smaller than the neutron production spot size and detector size can be detected and characterized depending upon the measurement time.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

An interactive ontology-driven information system for simulating background radiation and generating scenarios for testing special nuclear materials detection algorithms

This paper describes an original approach to generating scenarios for the purpose of testing the algorithms used to detect special nuclear materials (SNM) that incorporates the use of ontologies. Separating the signal of SNM from the background requires sophisticated algorithms. To assist in developing such algorithms, there is a need for scenarios that capture a very wide range of variables affecting the detection process, depending on the type of detector being used. To provide such a cpability, we developed an ontology-driven information system (ODIS) for generating scenarios that can be used in creating scenarios for testing of algorithms for SNM detection. The ontology-driven scenario generator (ODSG) is an ODIS based on information supplied by subject matter experts and other documentation. The details of the creation of the ontology, the development of the ontology-driven information system, and the design of the web user interface (UI) are presented along with specific examples of scenarios generated using the ODSG. We demonstrate that the paradigm behind the ODSG is capable of addressing the problem of semantic complexity at both the user and developer levels. Compared to traditional approaches, an ODIS provides benefits such as faithful representation of the users' domain conceptualization, simplified management of very large and semantically diverse datasets, and the ability to handle frequent changes to the application and the UI. Furthermore, the approach makes possible the generation of a much larger number of specific scenarios based on limited user-supplied information

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

Feasibility and Demonstration of a Cloud-Based RIID Analysis System (Annual Report)

A significant limitation in the operational utility of handheld and backpack radioisotope identifiers (RIIDs) is the ability of their onboard algorithms to accurately and reliably identify the isotopic sources of the measured gamma-ray energy spectrum and thereby separate threat from benign or background sources. Improved algorithms exist but are not implemented on RIIDs due to insufficient computational power or classification, export controls, or other sensitivities. They also have limited ability to use additional contextual information in making a threat no-threat assessment. A possible solution is to move the spectral analysis computations to an external device whose capabilities can be greatly enhanced and whose algorithms can be kept secure. A Cloud-based analysis system can provide this capability. Cloud computing is becoming ubiquitous and affords the national security community an opportunity for tremendous leverage of private sector developments. The goal of this project is to determine if operational performance of RIIDs can be improved by applying these developments in a way that meets the needs of the national security community.

Wright, Michael C.↗
DOE OSTI2010

Fieldable Nuclear Material Identification System

The Fieldable Nuclear Material Identification System (FNMIS), funded by the NA-241 Office of Dismantlement and Transparency, provides information to determine the material attributes and identity of heavily shielded nuclear objects. This information will provide future treaty participants with verifiable information required by the treaty regime. The neutron interrogation technology uses a combination of information from induced fission neutron radiation and transmitted neutron imaging information to provide high confidence that the shielded item is consistent with the host's declaration. The combination of material identification information and the shape and configuration of the item are very difficult to spoof. When used at various points in the warhead dismantlement sequence, the information complimented by tags and seals can be used to track subassembly and piece part information as the disassembly occurs. The neutron transmission imaging has been developed during the last seven years and the signature analysis over the last several decades. The FNMIS is the culmination of the effort to put the technology in a usable configuration for potential treaty verification purposes.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗