Performance of the Multi-sensor Interdiction System Testbed (MIST) Advanced Technology Demonstration (ATD) for Detection and Tracking of Vehicle-borne Radiation Sources (#3295)
D. A. Cooper2, R. J. Ledoux2, S. E. Korbly2, W. Franklin2, J. Costales2, R. Niyazov2, K. Kamieniecki2, L. Janney2, C. Monnier1, R. Wronski1, A. Ost1
1 Charles River Analytics, Inc., Cambridge, Massachusetts, United States of America
The threat represented by loose radioactive materials in the form of radiation dispersal devices (RDDs) and special nuclear materials (SNM) has continued to increase in recent years. Passport Systems, Inc. and Charles River Analytics, Inc. have developed the prototype Multi-sensor Interdiction System Testbed (MIST) to monitor roads and highways without affecting the flow of commerce. The system is highly modular consisting of a distributed network of heterogeneous detectors (radiation detectors, video cameras, and license plate readers) designed as a robust, cost-effective solution for detecting and identifying radioactive threats, tracking source vehicles, and supporting interdiction by law enforcement. The system is being developed as part of the Radiation Awareness and Interdiction Network (RAIN) Advanced Technology Demonstration (ATD) program sponsored by the US Dept. of Homeland Security, Domestic Nuclear Detection Office (DHS/DNDO). The prototype system has completed both Vendor Development Testing (VDT) and Technology Demonstration & Characterization (TD&C). Moreover, the system continues to undergo evaluation using validated replay and simulation tools also developed as part of the ATD program. Initial results indicate that the performance of the system utilizing advanced data fusion algorithms meets or exceeds the requirements laid out in the program Broad Area Announcement (BAA). Detailed results for both the physical testing and the replay/simulation efforts will be presented. Additionally, lessons learned will be provided along with the algorithm improvements made based on testing results. Finally, the system’s readiness for operational deployment during the program’s final phase will be provided. This work has been supported by the US Dept. of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract HSHQDC-14-C-B0049. This support does not constitute an express or implied endorsement on the part of the Government.
Keywords: Homeland Security, Radiation Detection, Data Fusion, detection algorithms, classification algorithms, Sensor fusion, Nuclear Physics
Cf-252 Spontaneous Fission Prompt Neutron and Gamma-ray Correlations (#3589)
M. J. Marcath1, P. Schuster1, S. D. Clarke1, P. Talou2, R. C. Haight2, M. Devlin2, R. Vogt3, 4, J. Randrup5, S. A. Pozzi1
1 University of Michigan, Nuclear Engineering and Radiological Sciences, Ann Arbor, Michigan, United States of America
New, event-by-event, physics-based models, CGMF (Los Alamos National Laboratory) and FREYA (Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory) predict correlations in prompt fission emissions. Characteristic neutrons and photons are emitted from nuclear fission when a deformed, neutron-rich nucleus divides into two fragments that then de-excite. During de-excitation, neutrons are emitted first, followed by photons; this process gives rise to correlations. Current safeguards and nonproliferation systems do not utilize correlations between particle types, but new systems could. Little data exist to validate these models; previously, correlated quantities have been measured only for Cf-252 spontaneous fission. High-order Cf-252 spontaneous fission neutron and gamma-ray coincidences were measured with an array of 45 liquid organic scintillation detectors and a fission chamber. In this work, measured coincidence data including neutron time-of-flight and measured gamma-ray pulse height distributions are compared with MCNPX-PoliMi simulation results from built-in and event-by-event fission models.
Keywords: fission, organic scintillators, simulation
Which is better, a SCoTSS gamma imager, or an ARDUO UAV-borne directional detector? (#3386)
A. McCann1, L. E. Sinclair1, P. R. B. Saull2, A. M. L. MacLeod2, R. Fortin1, C. Chen1, M. J. Coyle1, R. A. Van Brabant1, J. Hovgaard3, B. Krupskyy3
1 Geological Survey of Canada, Natural Resources Canada, Ottawa, Ontario, Canada
An SiPM-based Compton Telescope for Safety and Security (SCoTSS) has been developed using CsI(Tl) in both the scatterer and absorber layers. In survey mode, the imager accumulates spectra second by second, providing sensitive alarming based on recognition of peaks from man-made isotopes. Spectra are also tagged with GPS position such that a radiometric map can be produced. The Advanced Radiation Detector for Unmanned Aerial Vehicle Operations (ARDUO) on the other hand, is a non-imaging directional detector intended for use aboard a small unmanned aerial vehicle (UAV). The ARDUO detector features exactly the same volume of CsI(Tl) as is used in the absorber layer of a single SCoTSS module, giving it similar detection and alarming sensitivity, and map-making capability. So, which is better? The SCoTSS imager of course has the advantage of being able to produce an image of the radioactive objects in its field of view. However, on board a UAV, the ARDUO directional detector could perform a grid search, also producing an image of an area. In this presentation we investigate the relative merits of Compton imaging versus mobile directional detection. Using results from both experiment and simulation, survey and stationary applications are investigated, and both real-time and post-processing analyses are shown. Recommendations for optimal tools for different operating scenarios are provided.
Keywords: Simulation, Compton imaging, Geant4EGS, scintillators, point-source, map-making
Practical Testing of a Wearable Dual -Mode Search Instrument for Security Applications (#3391)
M. A. Foster1, M. Cobbett1, P. Salimi1, M. Dallimore2
1 Symetrica Security Ltd, Southampton, Hampshire, United Kingdom of Great Britain and Northern Ireland
Following the successful development of a wearable neutron search instrument its functionality was extended to include gamma-ray detection and search, aimed and security and policing applications.
The system comprises four low-profile detector modules of 22 x 8 x 2.5 cm that are worn by the operator. Fast neutrons moderated in their body are captured using a 6LiF/ZnS thermal neutron detector which is viewed by a silicon photomultiplier array. In this way comparable neutron sensitivity to an ANSI N42.53-2013 backpack system can be achieved with greatly reduced bulk and weight. This study included selection of a gamma-ray detection technology, simulating performance of a bar of caesium iodide with silicon photomultiplier readout and using a thin plate of plastic scintillator. This combined neutron/gamma detector is made possible by advanced discrimination logic which prevents cross-talk between the two output channels (neutron, gamma), achieving a gamma-ray rejection of 1:10E8. Neutron events are also removed from the gamma-ray channel to prevent false alarms from occurring.
Data in the form of neutron and gamma-ray count rates is read from the modules by either USB or BlueTooth Low Energy (BTLE) communication with an Android smartphone. A custom application running on the smartphone runs anomaly detection logic to alert the user to the presence of neutron and gamma sources and, by analysing the relative count rates reported by the modules, estimates the direction to the source. The collated results are geotagged and then sent to a central reachback server, allowing other personnel to read the data and aid decision making.
The above system has been tested by simulating a search situation. Operators were provided with a system and tasked with finding a 20,000 n/s Cf-252 source and an 80µCi Cs-137 source in the shortest time. Both indoor and outdoor scenarios were tested and repeated with a VeriFinder handheld RIID to provide a control.
Keywords: Source localisation, neutron detector, LiF:ZnS
Standoff Characterization of Highly Enriched Uranium using a Dual Particle Imaging System (#3431)
S. D. Clarke1, M. C. Hamel1, T. H. Shin1, S. A. Pozzi1
1 University of Michigan, Department of Nuclear Engineering & Radiological Sciences, Ann Arbor, Michigan, United States of America
The weak passive emissions of highly enriched uranium (HEU) make timely detection very difficult, especially if any amount of shielding material is present. The specific activity of spontaneous 235U neutron emission is two orders of magnitude lower than that or 238U and six orders of magnitude lower than that of 240Pu. However, 235U has a sizable cross-section for the (n,f) reaction that can be exploited through interrogation with neutrons. In this work, AmLi sources were used to interrogate kilogram-scale masses of HEU at the Device Assembly Facility on the Nevada National Security Site. The response was recorded using the dual particle imaging system (DPI) developed at the University of Michigan, which is a combined Compton and neutron-scatter camera capable of spatial and spectral characterization of nuclear material. The response time of the liquid scintillators used in the DPI is on the order of nanoseconds, which is on the same time-scale of the fission chains induced in the HEU. This capability presents the possibility to directly analyze the fission chain dynamics to characterize the multiplication of the HEU samples. Results will show the discrimination of different quantities of HEU using the DPI.
Keywords: Neutron Imaging, Fission-chain Analysis, Neutron Spectroscopy
W-MON: a distributed network of radiation sensors to monitor radioactivity in waste (#4174)
D. Celeste1, A. Curioni1, F. Murtas1, D. Perrin1, S. Romano1, M. Silari1
1 CERN, Geneva, Switzerland
The W-MON project is an activity within the CERN Radiation Protection group, aimed at establishing a fully automated monitoring system for radiation levels in ordinary waste at CERN. The network is based on battery powered, small footprint radiation sensors, connected to a network suitable for Internet of Things type applications, eventually transferring data to the existing CERN SCADA system (REMUS ). The system provides one reading per hour, with sensitivity down to natural background. Starting in 2013, a suitable sensor has been identified and tested in realistic conditions. In parallel, the communication part of the network has been designed and is under development. Here we will present the project, summarize the results achieved so far and outline plans for further developments.
Keywords: radiation sensors