Dr. Sanjoy Mukhopadhyay Profile

Dr. Sanjoy Mukhopadhyay

Sr. Principal Scientist at Nevada National Security Site

SPIE Involvement:

Conference Program Committee | Author

Area of Expertise:

Experimental Nuclear Physics , Nuclear Radiation Detection , Neutron counting and multiplicity measurements , Pion absorption on light nuclei , Scintillators and semiconductors for gamma radiation detection

Profile Summary

• Design and implementation of web application allowing large volume of radiation measurement data exchange from an international platform. Wrote IAEA-published manuals on “International Radiation Monitoring Information System (IRMIS)” and “International Radiological Information Exchange (IRIX)”
• More than twenty-five years of extensive knowledge and research on advanced radiation detectors.
• Experience with radiation safety, shielding and dosimetry
• Experienced in using atmospheric dispersion and transport modeling codes like IMAAC, NARAC, HYSPLIT and HPAC for consequence management purposes.
• Advanced user of position sensitive multi-anode photomultipliers (PS-MA-PMT) & Solid-State Photomultiplier (SSPM) based gamma-ray imager
• Built a prototype neutron fission multiplicity counter using boron-lined STRAW detector
• Built a prototype multi-element neutron energy spectrometer
• Built a prototype portable hand-held gamma spectrometer (using largest commercially available crystal of LaBr3: Ce) with spectral data transmission capability.
• Benchmarked SrI2: Eu2+, CLYC: Ce, CLLB: Ce crystals for gamma and neutron detection and response functions
• Built networked sensor packages that collect radiological data, weather information and send the data over cell phone to a remote command post.
• Built a prototype dual sensor for gamma and neutron using 6Li-glass
• Built a prototype large area plastic scintillator detector for gamma ray measurements in the gross count mode.
• Built a prototype 6LiI: Eu detector for both gamma and thermal neutron measurements with a counter-display system using seven-segment LCD unit.

Publications (39)

Proceedings Article | 3 October 2023 Presentation + Paper

Presentation + Paper

High fidelity ground deposition measurement with robots after explosive radiological dispersion

Richard Maurer, Sanjoy Mukhopadhyay, Johnny Grimes, Paul Guss, Ron Guise

Proceedings Volume 12696, 1269602 (2023) https://doi.org/10.1117/12.2679178

KEYWORDS: Robots, Contamination, Sensors, Robotic systems, Explosives, Motion controllers, Emergency preparedness, Remote sensing, Radioisotopes, Global Positioning System

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Proceedings Article | 3 October 2023 Presentation + Paper

Presentation + Paper

From count rates to quantifying isotopic activities: field analysis of radiation monitoring data

Sanjoy Mukhopadhyay, Johnny Grimes, Luz Martinez

Proceedings Volume 12696, 126960G (2023) https://doi.org/10.1117/12.2687891

KEYWORDS: Gamma radiation, Sensors, Scintillators, Radioisotopes, Defense and security, Visualization, Europium, Solids, Crystals, Attenuation

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Proceedings Article | 4 October 2022 Presentation + Paper

Presentation + Paper

Review of direct neutron conversion and detection processes

Sanjoy Mukhopadhyay

Proceedings Volume 12241, 1224109 (2022) https://doi.org/10.1117/12.2632550

KEYWORDS: Sensors, Semiconductors, Scintillators

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Proceedings Article | 4 October 2022 Presentation + Paper

Presentation + Paper

Radiation detection system integration using multiple-input multiple-output radios

Sanjoy Mukhopadhyay, Mark Biery, Johnny Grimes

Proceedings Volume 12241, 122410K (2022) https://doi.org/10.1117/12.2632551

KEYWORDS: Sensors, Data communications, Data acquisition, Surveillance, Network security, Data fusion, Telecommunications, System integration

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Proceedings Article | 1 September 2021 Presentation + Paper

Presentation + Paper

Evaluation and benchmarking of a commercial cadmium zinc telluride (CZT) gamma imaging camera

Sanjoy Mukhopadhyay, Richard Maurer, Paul Guss, Mark Biery

Proceedings Volume 11838, 1183805 (2021) https://doi.org/10.1117/12.2593456

KEYWORDS: Imaging systems, Gamma ray imaging, Cesium, Sensors, Spatial resolution, Coded apertures, Photons, Manufacturing, Crystals

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Proceedings Article | 20 August 2020 Presentation + Paper

Presentation + Paper

Newer aerial platform for emergency response by the United States Department of Energy

Sanjoy Mukhopadhyay, Richard Maurer, Paul Guss

Proceedings Volume 11494, 114940D (2020) https://doi.org/10.1117/12.2560116

KEYWORDS: Sensors, Hyperspectral imaging, Gamma radiation, Data acquisition, Visualization, Contamination, Remote sensing, Multispectral imaging, LIDAR

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Aerial radiological search and survey missions have been performed by the United States Department of Energy's (USDOE) Remote Sensing Laboratory for over 40 years. Originally created in 1967 as Aerial Measurement Operations, the Aerial Measuring System (AMS) mission has expanded to include acquiring baseline measurements, performing periodic site monitoring, and responding to radiological emergencies. In an accident scenario, AMS fixedwing and/or rotary-wing systems can be deployed to map radiological deposition. The aircraft are equipped to detect and measure radioactive contamination on the ground. The AMS has a sophisticated radiation detection system to gather radiological information and store it on the cloud using the Advanced Visualization and Integration of Data (AVID) platform or on local computers. This large amount of radiation monitoring data is later used to define and implement public protective guidance. Aerial radiation measurements have proven to be very effective in support of responses to nuclear or radiological emergencies resulting in the dispersal of radioactive material over a large area [viz. Fukushima Daiichi Nuclear power plant measurements done through March and April 2011] [1]. Right after the Fukushima accident, US aerial missions flew 85 flights over 500 hours, covering more than 10,000 square kilometres from the power plant to an 80 km radius to create a common operating picture of the extent of the gamma-emitting radionuclides and the footprint of the deposition from multiple releases. In order to be effective, the aerial measurements must be performed with a system that will collect the data in sufficient detail and quality to support the needs of emergency responders. This paper briefly outlines the technical specifications and functions of a system to be used on an aerial platform (airplane or helicopter) to measure widespread radioactive material (radioactive contamination). The information contained within this paper is intended to help ensure that measurements conducted by multiple AMSs are both technically compatible and comparable with each other and with measurements taken on the ground. Recently AMS has acquired newer and faster aircraft with longer-than-before ranges to deploy radiation monitoring equipment. This article defines and provides guidance for using the US DOE/NNSA’s new aerial measurement platforms with multi-fold return of the investment in mind. The guidance involves technical innovation and optimized use of the platforms and collaboration with other stakeholders like the Department of Homeland Security, the Nuclear Regulatory Commission, and the Environmental Protection Agency. The guidance recommends AMS to reposition itself as a valid and credentialed data provider to other relevant and recognized stakeholders in the area of chemical, biological, radiological, nuclear, and explosives threats. It recommends critical application expansion for AVID to analyse multi-modal data including hyperspectral, infrared, and radiological data through data fusion.

Proceedings Article | 20 August 2020 Presentation + Paper

Presentation + Paper

Modern trends in gamma detection systems for emergency response

Sanjoy Mukhopadhyay, Richard Maurer, Paul Guss

Proceedings Volume 11494, 114940B (2020) https://doi.org/10.1117/12.2560115

KEYWORDS: Scintillators, Sensors, Gamma radiation, Semiconductors, Imaging systems, Crystals, Cesium, Gamma ray imaging, Algorithm development, Electrons

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The scope and applicability of detecting gamma-emitting materials by first responders and advanced searchers have changed considerably over the last 15 years. More often than not the searchers are being asked to obtain an image of the gamma sources that are shielded or otherwise inaccessible. They are constantly being tasked to localize a moving source in busy traffic. Commercially available gamma detection units and prototype Government-funded research products use complex techniques such as hybrid imaging processes (combination of traditional Compton imaging with coded aperture masks, for example, modified uniformly redundant array [MURA] patterns). Standalone radiation detection systems are increasingly capitalizing on multi-modal detection, emphasizing on data fusion, informatics, and novel signal/signature exploitations. At the request of the U.S. Department of Homeland Security (DHS) Countering Weapons of Mass Destruction (CWMD) Office, previously known as the Domestic Nuclear Detection Office (DNDO), a study committee from the American Physical Society has recommended that emphasis is kept on the ability to detect shielded special nuclear material with high sensitivity and reliability. Development of new and improved detection algorithms (e.g., principal component analysis, maximum-likelihood estimation algorithm, and others) has been encouraged. CWMD has been urged to focus on signature identification in its nuclear forensic portfolio. Newer materials like SrI₃:Eu²⁺, LaBr₃:Ce, CeBr₃:Ca²⁺ with fast rise time and short decay time of gamma pulses, high intrinsic gamma sensitivity, high gamma energy resolution, and high-efficiency conversion of excitation energy to fluorescent radiation are constantly being sought to build gamma detectors. Neutron detection and associated activation analysis using a gamma ray detection system is highly encouraged. There is a constant demand for miniaturization of gamma radiation detection system for tactical usage in the field– the most sought-after device must be lightweight, easy to use, should be able to withstand harsh environmental conditions, long shelf life with commensurate long battery life, high sensitivity (with preferably high resolution), capable of creating flexible and configurable alarm conditions with directional sensitivity. This array of technical constraints demands stringent specifications on the readout electronics, data acquisition technologies, interoperability and interconnectivity of data output and strict quality assurance of the detection and measurement devices. In recent years the CWMD has developed a system called Intelligent Radiation Sensing System (IRSS) that harnesses the information gathered by ubiquitous radiation monitoring systems deployed by the state, local, and tribal law enforcement organizers [1]. The IRSS was created to better equip law enforcement entities to protect large cities from the threats and harmful effects of nuclear or radiological incidents and emergencies. The IRSS uses a breakthrough technology that networks a group of portable radiation detectors with improved detection, localization, and identification of potential radiological threat. The program created a robust, flexible network architecture along with advanced data fusion algorithms that combine information from many detectors. A study [2] published in the Journal of Materials Research summarized the basic requirements for materials to be used in development of scalable radiation detection systems that considered the critical material performance metrics of energy resolution (1% for semiconductors like CZT, <3% for scintillators like LaBr₃:Ce at 662 keV primary gamma ray energy from ¹³⁷Cs isotope), fast timing including high mobility of electrons and holes in the semiconductors and fast scintillation processes, high spatial resolution for imaging purposes, high intrinsic detection efficiency (requiring high density, high effective atomic number Z_eff), high geometric efficiency achieved sometimes by occlusion processes, neutron detection efficiency and operational factors like cost, ease of use, use of peripheral equipment like thermomechanical engines to stabilize the detection systems. Exciting new research and development work utilizing effective data mining algorithms is being performed at universities, national laboratories, and commercial institutions in gamma ray detection technology. For example, gamma ray imaging techniques first used in space telescopes are being applied in modern security and health systems in a joint project between the University of Southampton and industrial partner Symetrica. The project aims to develop a new coded aperture imaging system that could inspire a new generation of “stand-off” imaging systems. These systems would allow for remote inspection for radioactive materials. This review article intends to capture the synergy of international commercial collaborations exemplified by the United States Defense Advanced Research Projects Agency’s (DARPA’s) SIGMA program in which detector expertise originating from the United Kingdom (Kromek Group plc.) algorithm development and system modelling and analysis developed by United States national laboratories came together under the general guidance provided by a small commercial unit, Invincea Labs, in the area of network algorithm integration and development.

Proceedings Article | 9 September 2019 Presentation + Paper

Presentation + Paper

Reformatting data from common emergency radiation measurement systems into International Radiological Information Exchange (IRIX) for harmonization

Sanjoy Mukhopadhyay, Florian Baciu, Gurdeep Saluja, Jose Segarra, Franck Albinet

Proceedings Volume 11114, 111141F (2019) https://doi.org/10.1117/12.2526110

KEYWORDS: Standards development, Computing systems, Data conversion, Visualization, Gamma radiation, Spectroscopy, Global Positioning System, Geographic information systems, Environmental monitoring, Sensors

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From the experience during radiation monitoring and data analysis of Fukushima Dai-ichi Accident it was learned that the large amount of data gathered during the nuclear emergency by multi-national organizations needs to be harmonized to speak in “one voice” regarding the evolving radiological status of the environment around the accident location. The International Atomic Energy Agency (IAEA)’s Incident and Emergency Centre (IEC) has introduced the International Radiological Information Exchange (IRIX) [1], a technical standard developed by the IAEA, in cooperation with experts from Member States and the European Commission (EC), meant to enable the development of interoperable systems and solutions for exchanging emergency information and data between organisations at both national and international levels during a nuclear or radiological emergency. IRIX works as the data format for the International Radiation Monitoring Information System (IRMIS) [2], a client server-based web application that provides users a platform to report and visualize large quantities of radiological monitoring data during nuclear and radiological emergencies. IRMIS routinely receives the radiation dose rate data from fixed monitoring stations from close to 40 Member States. The information reported and the tools provided within IRMIS may be used in the decisionmaking process related to the implementation of public protective actions and other response actions during a nuclear or radiological emergency. The IRIX standard comprises two parts: a standard data format and a standard web service interface definition. Among the first applications of the IRIX standards are the interconnection and enabling of automated information exchange between the IAEA’s Unified System for Information Exchange in Incidents and Emergencies (USIE) and the European Community Urgent Radiological Information Exchange system (WebECURIE) [3], and the interchange of environmental radiation monitoring data in the IAEA’s IRMIS. The IAEA-IEC has worked on several emergency radiation monitoring equipment like backpacks, vehicle mounted large sensitivity gamma radiation detectors and has converted the data reports produced by these detection systems into IRIX format so that they could be assimilated in to the IRMIS. The current project has developed interactive decision support not only in the area of public protection but also in optimizing resource allocation during radiological emergencies. One of the main challenges in coordinating a large scale nuclear emergency response is identifying progress of task allocation, sample collection and analysis for a smooth flow of data in response operations. Geographic record of this progress, in the form of a map, can assist in the optimization of resource allocation, and so ensure that demand for sample collector and laboratory services is matching the supply. The adoption of the IRIX format to package radiation monitoring data in a machine readable extensible mark-up language (XML) has reduced the time and human effort (and associated errors) drastically. The language can be universally applied to all types of radiation monitoring and environmental sampling systems. Coupled with the IRMIS system of data management, visualization and analysis tools, IRIX can help analysis of resource gaps (how to distribute monitoring resources most efficiently and effectively) and can become a very strong deployment tool for the Member States. Standardized emergency monitoring data reports from different operational monitoring equipment will go a long way in harmonizing radiation monitoring data acquisition and analysis at national levels to have a sustainable global impact. The ideal system, anticipated to support up to millions of entries of sample and monitoring data, optimizes the data query system and utilizes the least core information to quickly answer questions needed in decision making during emergencies. Incorporating the IRIX format can be an effective part of such new systems.

Proceedings Article | 11 September 2018 Presentation + Paper

Presentation + Paper

Application of International Radiological Information Exchange (IRIX) standards for radiation monitoring data reporting

Sanjoy Mukhopadhyay, Florian Baciu, Gurdeep Saluja, Jose Segarra, Franck Albinet

Proceedings Volume 10763, 1076308 (2018) https://doi.org/10.1117/12.2309380

KEYWORDS: Environmental monitoring, Standards development, Data communications, Visualization, Human-machine interfaces, Data processing, Data acquisition, Computer programming, Environmental sensing, Time metrology

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The IAEA has developed the International Radiation Monitoring Information System (IRMIS), an international web- based application in support of the implementation of the Convention on Early Notification of a Nuclear Accident. IRMIS provides a mechanism for the reporting and visualization of large quantities of environmental radiation monitoring data during nuclear or radiological emergencies. The radiation monitoring data can be uploaded to IRMIS in the International Radiological Information Exchange (IRIX) format. A web interface has been designed in IRMIS through which authorized users may upload the reports of Emergency Data into IRMIS, either in IRIX format or using a pre-formatted spreadsheet template. These reports are subsequently reviewed and published on IRMIS by the IAEA Incident and Emergency Centre (IEC). IRIX is a technical standard developed by the IAEA in cooperation with experts from Member States and the European Commission (EC). It is designed to enable the development of interoperable systems and solutions for exchanging emergency information and data between organizations at both national and international level during a nuclear or radiological incident or emergency. IRIX is an open format developed by the IAEA based on the Extensible Markup Language (XML), which makes it both machine- and human-readable. It should be used to exchange radiological information between IAEA and RANET teams, or between any other two (or more) assisting parties, during a nuclear or radiological emergency. The IAEA has developed the IRIX format as the recommended standard to exchange information among emergency response organizations at national and international levels during a nuclear or radiological emergency. The standard covers the data content, the data format (XML), and the system interface specification. Data can include status information about a nuclear installation, information about any radioactive releases to the environment, information on protective actions taken or planned by affected countries, and environmental radiation monitoring data. The system interface specification (or web-service specification) enables organizations to interconnect their emergency information systems to automate their information exchange in an emergency. The IRIX standard allows the information to be processed quickly, summarized, and presented in an easily understood format: for example, on status boards in emergency response centres. Once the national system has been interconnected with a counterpart system, the information contained in reports in the IRIX format can be automatically exchanged via “machine-to-machine” transactions. These can replace or complement “operator-to-machine” or “operator-to-operator” information exchange, which is usually slower and not error-free. At present, US DOE/NNSA efforts to collect and share large quantities of radiological or nuclear emergency monitoring data are fragmented. The Emergency Response Group acquires data using multiple cell-nets, and communicates these data back to the Search Management Centre (SMC), which produces maps and briefing products. The RAP regions--which are vast--are using the RadResponder Network that is outside the scope of SMC and mainstream NNSA emergency response. The IAEA proposes to integrate all types of radiation data--survey, monitoring, environmental, and sampling — under one international umbrella, the International Radiation Monitoring Information System (IRMIS). The most significant restriction is that SMC is not a client server based system, whereas IRMIS is a distributed web- based application: it is managed by issuing user-level credentials with multi-level privileges. Unlike SMC, IRMIS is also independent of the origin and type of equipment used to collect the data (e.g. backpack, vehicle monitoring, or networked fixed-monitoring stations).

Proceedings Article | 11 September 2018 Presentation + Paper

Presentation + Paper

Harmonization of radiation monitoring and environmental sampling data in the aftermath of a nuclear or radiological emergency

Sanjoy Mukhopadhyay, Florian Baciu, Kilian Smith, Katerina Kouts, Phillip Vilar Welter

Proceedings Volume 10763, 1076309 (2018) https://doi.org/10.1117/12.2309467

KEYWORDS: Environmental monitoring, Statistical analysis, Sensors, Calibration, Standards development, Environmental sensing, Safety, Cesium, Atmospheric monitoring, Contamination

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Proceedings Article | 7 September 2017 Presentation + Paper

Presentation + Paper

International Radiation Monitoring and Information System (IRMIS)

Sanjoy Mukhopadhyay, Florian Baciu, Jan Stowisek, Gurdeep Saluja, Patrick Kenny, Franck Albinet

Proceedings Volume 10393, 1039305 (2017) https://doi.org/10.1117/12.2275207

KEYWORDS: Safety, Visualization, Environmental monitoring, Process control, Situational awareness sensors, Visual analytics, Environmental sensing, Homeland security

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This article describes the International Radiation Monitoring Information System (IRMIS) which was developed by the International Atomic Energy Agency (IAEA) with the goal to provide Competent Authorities, the IAEA and other international organizations with a client server based web application to share and visualize large quantities of radiation monitoring data. The data maps the areas of potential impact that can assist countries to take appropriate protective actions in an emergency.

Ever since the Chernobyl nuclear power plant accident in April of 19861 European Community (EC) has worked towards collecting routine environmental radiological monitoring data from national networked monitoring systems. European Radiological Data Exchange Platform (EURDEP) was created in 19952 to that end – to provide radiation monitoring data from most European countries reported in nearly real-time.

During the response operations for the Fukushima Dai-ichi nuclear power plant accident (March 2011) the IAEA Incident and Emergency Centre (IEC) managed, harmonized and shared the large amount of data that was being generated from different organizations. This task underscored the need for a system which allows sharing large volumes of radiation monitoring data in an emergency.

In 2014 EURDEP started the submission of the European radiological data to the International Radiation Monitoring Information System (IRMIS) as a European Regional HUB for IRMIS. IRMIS supports the implementation of the Convention on Early Notification of a Nuclear Accident by providing a web application for the reporting, sharing, visualizing and analysing of large quantities of environmental radiation monitoring data during nuclear or radiological emergencies.

IRMIS is not an early warning system that automatically reports when there are significant deviations in radiation levels or when values are detected above certain levels. However, the configuration of the visualization features offered by IRMIS may help Member States to determine where elevated gamma dose rate measurements during a radiological or nuclear emergency indicate that actions to protect the public are necessary. The data can be used to assist emergency responders determine where and when to take necessary actions to protect the public.

This new web online tool supports the IAEA’s Unified System for Information Exchange in Incidents and Emergencies (USIE)3, an online tool where competent authorities can access information about all emergency situations, ranging from a lost radioactive source to a full-scale nuclear emergency.

Proceedings Article | 7 September 2017 Presentation + Paper

Presentation + Paper

High-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array

Paul Guss, Michael Rabin, Mark Croce, Nathan Hoteling, David Schwellenbach, Craig Kruschwitz, Veronika Mocko, Sanjoy Mukhopadhyay

Proceedings Volume 10393, 1039308 (2017) https://doi.org/10.1117/12.2272639

KEYWORDS: Sensors, Microwave radiation, Spectroscopes, Multiplexing, Superconductors, Gamma radiation, Optical resolution, Resonators, Phase shift keying, Modulation

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Proceedings Article | 7 September 2017 Presentation + Paper

Presentation + Paper

Small unmanned aircraft system for remote contour mapping of a nuclear radiation field

Paul Guss, Karen McCall, Russell Malchow, Rick Fischer, Michael Lukens, Mark Adan, Ki Park, Roy Abbott, Michael Howard, Eric Wagner, Clifford Trainham, Tanushree Luke, Sanjoy Mukhopadhyay, Paul Oh, Pareshkumar Brahmbhatt, Eric Henderson, Jinlu Han, Justin Huang, Casey Huang, Jon Daniels

Proceedings Volume 10393, 1039304 (2017) https://doi.org/10.1117/12.2272614

KEYWORDS: Sensors, Nuclear radiation, Nuclear radiation detection, Scintillators, Algorithm development, Contamination, Safety, Electro optical sensors, Electro optical systems, Detection and tracking algorithms

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Proceedings Article | 27 August 2015 Paper

Paper

Maximum likelihood source localization using elpasolite crystals as a dual gamma neutron directional detector

Paul Guss, Thomas Stampahar, Sanjoy Mukhopadhyay, Alexander Barzilov, Amber Guckes

Proceedings Volume 9595, 959502 (2015) https://doi.org/10.1117/12.2186179

KEYWORDS: Sensors, Detection and tracking algorithms, Crystals, Gamma radiation, Scintillators, Chlorine, Algorithm development, Environmental management, Cerium, Statistical analysis

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Proceedings Article | 26 August 2015 Paper

Paper

Linearity response of Ca2+-doped CeBr3 as a function of gamma-ray energy

Paul Guss, Michael Foster, Bryan Wong, F. Doty, Kanai Shah, Michael Squillante, Urmila Shirwadkar, Rastgo Hawrami, Josh Tower, Thomas Stampahar, Sanjoy Mukhopadhyay

Proceedings Volume 9593, 959304 (2015) https://doi.org/10.1117/12.2186181

KEYWORDS: Crystals, Calcium, Doping, Scintillators, Sensors, Spectroscopy, Ions, Cerium, Gamma radiation, Photons

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Proceedings Article | 26 August 2015 Paper

Paper

Radiation anomaly detection algorithms for field-acquired gamma energy spectra

Sanjoy Mukhopadhyay, Richard Maurer, Ron Wolff, Paul Guss, Stephen Mitchell

Proceedings Volume 9593, 95930S (2015) https://doi.org/10.1117/12.2185736

KEYWORDS: Sensors, Gamma radiation, Detection and tracking algorithms, Algorithm development, Principal component analysis, Radioisotopes, Surgery, Scintillators, Calibration, Security technologies

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Proceedings Article | 26 August 2015 Paper

Paper

Networked gamma radiation detection system for tactical deployment

Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff, Ethan Smith, Paul Guss, Stephen Mitchell

Proceedings Volume 9593, 959316 (2015) https://doi.org/10.1117/12.2185843

KEYWORDS: Sensors, Gamma radiation, Crystals, Detection and tracking algorithms, Data acquisition, Security technologies, Sodium, Remote sensing, Radioisotopes, Sensor networks

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Proceedings Article | 5 September 2014 Paper

Paper

Review of current neutron detection systems for emergency response

Sanjoy Mukhopadhyay, Richard Maurer, Paul Guss, Craig Kruschwitz

Proceedings Volume 9213, 92130T (2014) https://doi.org/10.1117/12.2058165

KEYWORDS: Sensors, Semiconductors, Scintillators, Diodes, Particles, Gamma radiation, Signal processing, Crystals, Microchannel plates, Photons

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Proceedings Article | 5 September 2014 Paper

Paper

Semiconductor neutron detectors using depleted uranium oxide

Craig Kruschwitz, Sanjoy Mukhopadhyay, David Schwellenbach, Thomas Meek, Brandon Shaver, Taylor Cunningham, Jerrad Philip Auxier

Proceedings Volume 9213, 92130C (2014) https://doi.org/10.1117/12.2063501

KEYWORDS: Sensors, Uranium, Semiconductors, Oxides, Crystals, Semiconductor materials, Diodes, Crystallography, Fabrication, Security technologies

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Proceedings Article | 5 September 2014 Paper

Paper

Use of a position-sensitive multi-anode photomultiplier tube for finding gamma-ray source direction

Sanjoy Mukhopadhyay, Richard Maurer, Paul Guss

Proceedings Volume 9213, 92131A (2014) https://doi.org/10.1117/12.2066238

KEYWORDS: Sensors, Gamma radiation, Spectroscopy, Photomultipliers, Crystals, Data acquisition, Spatial resolution, Sodium, Interfaces, Security technologies

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Proceedings Article | 4 September 2014 Paper

Paper

Scintillation properties of a Cs2LiLa(Br6)90%(Cl6)10%:Ce3+ (CLLBC) crystal

Paul Guss, Thomas Stampahar, Sanjoy Mukhopadhyay, Alexander Barzilov, Amber Guckes

Proceedings Volume 9215, 921505 (2014) https://doi.org/10.1117/12.2060204

KEYWORDS: Sensors, Crystals, Scintillation, Chlorine, Photons, Lithium, Cerium, Luminescence, Scintillators, Remote sensing

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Proceedings Article | 4 September 2014 Paper

Paper

Rapid response radiation sensors for homeland security applications

Sanjoy Mukhopadhyay, Richard Maurer, Paul Guss

Proceedings Volume 9215, 921504 (2014) https://doi.org/10.1117/12.2066666

KEYWORDS: Sensors, Gamma radiation, Scintillators, Data acquisition, Detection and tracking algorithms, Spectroscopy, Homeland security, Uranium, Security technologies, Remote sensing

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Proceedings Article | 26 September 2013 Paper

Paper

Direction-sensitive hand-held gamma-ray spectrometer

Sanjoy Mukhopadhyay

Proceedings Volume 8852, 885218 (2013) https://doi.org/10.1117/12.2018350

KEYWORDS: Sensors, Gamma radiation, Crystals, Spectroscopy, Scintillators, Analog electronics, Solid state electronics, Photonic crystals, Photomultipliers, Europium

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Proceedings Article | 26 September 2013 Paper

Paper

Dual gamma/neutron directional elpasolite detector

Paul Guss, Sanjoy Mukhopadhyay

Proceedings Volume 8854, 885402 (2013) https://doi.org/10.1117/12.2021341

KEYWORDS: Sensors, Cerium, Crystals, Scintillators, Doping, Sensor performance, Detector arrays, Cesium, Gamma radiation, Spectroscopy

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Proceedings Article | 26 September 2013 Paper

Paper

Real-time active cosmic neutron background reduction methods

Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff, Stephen Mitchell, Paul Guss

Proceedings Volume 8854, 885408 (2013) https://doi.org/10.1117/12.2020895

KEYWORDS: Sensors, Scintillators, Cadmium, Boron, Logic, Manufacturing, Field programmable gate arrays, Monte Carlo methods, Picosecond phenomena, Lanthanum

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Neutron counting using large arrays of pressurized ³He proportional counters from an aerial system or in a maritime environment suffers from the background counts from the primary cosmic neutrons and secondary neutrons caused by cosmic ray‒induced mechanisms like spallation and charge-exchange reaction. This paper reports the work performed at the Remote Sensing Laboratory–Andrews (RSL-A) and results obtained when using two different methods to reduce the cosmic neutron background in real time. Both methods used shielding materials with a high concentration (up to 30% by weight) of neutron-absorbing materials, such as natural boron, to remove the lowenergy neutron flux from the cosmic background as the first step of the background reduction process. Our first method was to design, prototype, and test an up-looking plastic scintillator (BC-400, manufactured by Saint Gobain Corporation) to tag the cosmic neutrons and then create a logic pulse of a fixed time duration (~120 μs) to block the data taken by the neutron counter (pressurized 3He tubes running in a proportional counter mode). The second method examined the time correlation between the arrival of two successive neutron signals to the counting array and calculated the excess of variance (Feynman variance Y2F)¹ in the neutron count distribution from Poisson distribution. The dilution of this variance from cosmic background values ideally would signal the presence of manmade neutrons.² The first method has been technically successful in tagging the neutrons in the cosmic-ray flux and preventing them from being counted in the ³He tube array by electronic veto—field measurement work shows the efficiency of the electronic veto counter to be about 87%. The second method has successfully derived an empirical relationship between the percentile non-cosmic component in a neutron flux and the Y2F of the measured neutron count distribution. By using shielding materials alone, approximately 55% of the neutron flux from man-made sources like ²⁵²Cf or Am-Be was removed.

Proceedings Article | 26 September 2013 Paper

Paper

Exploitation of geometric occlusion and covariance spectroscopy in a gamma sensor array

Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff, Stephen Mitchell, Paul Guss, Clifford Trainham

Proceedings Volume 8852, 88520H (2013) https://doi.org/10.1117/12.2019482

KEYWORDS: Sensors, Spectroscopy, Crystals, Scintillators, Gamma radiation, Compton scattering, Detector arrays, Sodium, Radioisotopes, Solids

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Proceedings Article | 24 October 2012 Paper

Paper

Direction sensitive neutron detectors in near field measurements

Sanjoy Mukhopadhyay, Stephen Mitchell

Proceedings Volume 8507, 85070S (2012) https://doi.org/10.1117/12.929975

KEYWORDS: Sensors, Mathematical modeling, Principal component analysis, Near field, Spatial resolution, Gamma radiation, Databases, Monte Carlo methods, Source localization, Homeland security

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Proceedings Article | 24 October 2012 Paper

Paper

Medical isotope identification with large mobile detection systems

Sanjoy Mukhopadhyay, Richard Maurer

Proceedings Volume 8507, 85071B (2012) https://doi.org/10.1117/12.929189

KEYWORDS: Sensors, Gamma radiation, Radioisotopes, Computing systems, Calibration, Surgery, Sodium, Scintillators, Remote sensing, Security technologies

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The Remote Sensing laboratory (RSL) of National Security Technologies Inc. has built an array of large (5.08 - cm x 10.16 – cm x 40.6 - cm) thallium doped sodium iodide (NaI: Tl) scintillators to locate and screen gamma-ray emitting radioisotopes that are of interests to radiological emergency responders [1]. These vehicle mounted detectors provide the operators with rapid, simple, specific information for radiological threat assessment. Applications include large area inspection, customs inspection, border protection, emergency response, and monitoring of radiological facilities. These RSL mobile units are currently being upgraded to meet the Defense Threat Reduction Agency mission requirements for a next-generation system capable of detecting and identifying nuclear threat materials. One of the challenging problems faced by these gamma-ray detectors is the unambiguous identification of medical isotopes like 131I (364.49 keV [81.7%], 636.99 keV [7.17%]), 99Tcm (140.51 keV [89.1%]) and 67Ga (184.6 keV [19.7%], 300.2 [16.0%], 393.5 [4.5%] that are used in radionuclide therapy and often have overlapping gamma-ray energy regions of interest (ROI). The problem is made worse by short (about 5 seconds) acquisition time of the spectral data necessary for dynamic mobile detectors. This article describes attempts to identify medical isotopes from data collected from this mobile detection system in a short period of time (not exceeding 5 secs) and a large standoff distance (typically ~ 10 meters) The mobile units offer identification capabilities that are based on hardware auto stabilization of the amplifier gain. The 1461 keV gamma-energy line from 40K is tracked. It uses gamma-ray energy windowing along with embedded mobile Gamma Detector Response and Analysis Software (GADRAS) [2] simultaneously to deconvolve any overlapping gamma-energy ROIs. These high sensitivity detectors are capable of resolving complex masking scenarios and exceed all ANSI N42.34 (2006) requirements for the identification of bare, shielded and multiple isotopes.

Proceedings Article | 19 October 2012 Paper

Paper

Preliminary results from an investigation into nanostructured nuclear radiation detectors for non-proliferation applications

Paul Guss, Ronald Guise, Ding Yuan, Sanjoy Mukhopadhyay

Proceedings Volume 8509, 85090D (2012) https://doi.org/10.1117/12.928675

KEYWORDS: Sensors, Nanocomposites, Nanoparticles, Scintillators, Zinc, Crystals, Composites, Polymers, Nuclear radiation, Gamma radiation

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Proceedings Article | 19 December 2011 Paper

Paper

Current trends in gamma radiation detection for radiological emergency response

Sanjoy Mukhopadhyay, Paul Guss, Richard Maurer

Proceedings Volume 8144, 81440K (2011) https://doi.org/10.1117/12.891963

KEYWORDS: Sensors, Gamma radiation, Scintillators, Crystals, Imaging systems, Semiconductors, Photons, Quantum dots, Sodium, Nanoparticles

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Proceedings Article | 28 September 2011 Paper

Paper

Prompt neutron multiplicity measurements with portable detectors

Sanjoy Mukhopadhyay, Ronald Wolff, Richard Maurer, Stephen Mitchell, Ethan Smith, Paul Guss, Jeffrey Lacy, L. Sun, A. Athanasiades

Proceedings Volume 8142, 81420T (2011) https://doi.org/10.1117/12.888656

KEYWORDS: Sensors, Fermium, Frequency modulation, Data acquisition, Prototyping, Gamma radiation, Copper, Field programmable gate arrays, Environmental sensing, Manufacturing

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Proceedings Article | 14 September 2011 Paper

Paper

Investigation into nanostructured lanthanum halides and CeBr3 for nuclear radiation detection

Paul Guss, Ronald Guise, Sanjoy Mukhopadhyay, Ding Yuan

Proceedings Volume 8144, 814405 (2011) https://doi.org/10.1117/12.890818

KEYWORDS: Sensors, Nanocomposites, Scintillators, Nanoparticles, Lanthanum, Nanostructuring, Quantum efficiency, Photons, Crystals, Gamma radiation

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Proceedings Article | 12 September 2009 Paper

Paper

Neutron energy measurements in emergency response applications

Sanjoy Mukhopadhyay, Paul Guss, Michael Hornish, Scott Wilde, Tom Stampahar, Michael Reed

Proceedings Volume 7449, 744913 (2009) https://doi.org/10.1117/12.824624

KEYWORDS: Scintillators, Lithium, Sensors, Fusion energy, Gadolinium, Crystals, Gamma radiation, Spectroscopy, Liquids, Yttrium

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We present significant results in recent advances in the measurement of neutron energy. Neutron energy measurements are a small but significant part of radiological emergency response applications. Mission critical information can be obtained by analyzing the neutron energy given off from radioactive materials. In the case of searching for special nuclear materials, neutron energy information from an unknown source can be of importance. At the Remote Sensing Laboratory (RSL) of National Security Technologies, LLC, a series of materials, viz., liquid organic scintillator (LOS), Lithium Gadolinium Borate (LGB) or Li₆Gd(BO₃)₃ in a plastic matrix, a recently developed crystal of Cesium Lithium Yttrium Chloride, Cs₂LiYCl₆: Ce (called CLYC)^[1], and normal plastic scintillator (BC-408) with 3He tubes have been used to study their effectiveness as a portable neutron energy spectrometer. Comparisons illustrating the strengths of the various materials will be provided. Of these materials, LGB offers the ability to tailor its response to the neutron spectrum by varying the isotopic composition of the key constituents (Lithium, Gadolinium [Yttrium], and Boron). All three of the constituent elements possess large neutron capture cross section isotopes for highly exothermic reactions. These compounds of composition Li₆Gd(Y)(BO₃)₃ can be activated by Cerium ions Ce³⁺. CLYC, on the other hand, has a remarkable gamma response in addition to superb neutron discrimination, comparable to that of Europium-doped Lithium Iodide (⁶LiI: Eu). Comparing these two materials, CLYC has higher light output (4500 phe/MeV) than that from ⁶LiI: Eu and shows better energy resolution for both gamma and neutron pulse heights. Using CLYC, gamma energy pulses can be discriminated from the neutron signals by simple pulse height separation. For the cases of both LGB and LOS, careful pulse shape discrimination is needed to separate the gamma energy signals from neutron pulses. Both analog and digital methods have been applied to obtain a clear gamma and neutron energy spectrum in a mixed radiation field. A waveform digitizer manufactured by Agilent Technology Inc. has been successfully used to digitize the signal and separate the gamma and neutron signals to obtain a high gamma rejection ratio. These results along with some interesting data from a plastic (BC-408) and ³He dual gamma-neuron detector will be presented.

Proceedings Article | 12 September 2009 Paper

Paper

Multi-element neutron energy spectrometer

Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff, Stephen Mitchell, Alexis Reed

Proceedings Volume 7449, 744914 (2009) https://doi.org/10.1117/12.824150

KEYWORDS: Spectroscopy, Sensors, Helium, Fusion energy, Multi-element lenses, Modulation, Energy efficiency, Monte Carlo methods, Solar energy, Gamma radiation

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In the area of nuclear radiological emergency response and preparedness applications, interest in neutron detection stems from several factors. Unlike gamma rays, which are abundant in nature and present serious difficulties in differentiating a signal from a changing background, whose values are location specific, neutrons are rare and nearly homogenous in spatial distribution. Additionally, many special nuclear materials (SNM) emit neutrons either directly by spontaneous fission or produce neutrons indirectly through (α, n) reactions in nearby light elements. Also of importance in detection scenarios is the fact that neutrons are not easily attenuated. Typically neutron detection is done by simply counting the low energy thermal neutrons by employing pressurized helium tubes operated at high voltages. Not much emphasis is put on determining the energy of the incident neutrons. However, critical information can be obtained by analyzing the neutron energy given off from radioactive materials. In the detection of an SNM, neutron energy information from an unknown source can be of paramount importance. We have modeled, designed, and prototyped multi-element neutron energy spectrometers that contain three to five pressurized helium tubes of dimensions 2" diam. x 10" in length. Each individual helium tube has a specific amount of high density plastic neutron moderators to slow down the incident energetic neutrons to an accurately estimated energy. A typical spectrometer is a set of moderator cylinders surrounding detectors that have high efficiency for detecting thermal neutrons. The larger the moderator, the higher the energy of incident neutrons for which the detector assembly has matched detection efficiency. If all the detectors are exposed to the same radiation field and the efficiency as a function of energy (response function) of each of the detectors is known, the neutron energy spectrum can be determined from the detector count rates. Monte Carlo simulation results of response function calculations for different arrays of helium tubes with varying amount of moderators will be shown. Experimental evidence of effectiveness of a set of moderated helium tubes to measure the hardness of the incident neutrons will be demonstrated.

Proceedings Article | 24 September 2007 Paper

Paper

Field-deployable gamma-radiation detectors for DHS use

Sanjoy Mukhopadhyay

Proceedings Volume 6706, 670612 (2007) https://doi.org/10.1117/12.738711

KEYWORDS: Sensors, Crystals, Lanthanum, Spectroscopy, Cerium, Gamma radiation, Sodium, Digital cameras, Global system for mobile communications, Monte Carlo methods

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Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS' requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER^TM, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack^TM that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field¹. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant spectral data and software-triggers the digital camera to take a snapshot. The spectral data including in situ analysis and the imagery data will be packaged in a suitable format and sent to a command post using an imbedded cell phone.

Proceedings Article | 10 May 2006 Paper

Paper

Wide area sensor network

Sanjoy Mukhopadhyay, Tricia Nix, Robert Junker, Josef Brentano, Dhiren Khona

Proceedings Volume 6201, 62011G (2006) https://doi.org/10.1117/12.649427

KEYWORDS: Sensors, Sensor networks, Geographic information systems, Radon, Data modeling, Stars, Homeland security, Telecommunications, Data centers, Electronics

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The technical concept for this project has existed since the Chernobyl accident in 1986. A host of Eastern European nations have developed countrywide grid of sensors to monitor airborne radiation. The objective is to build a radiological sensor network for real-time monitoring of environmental radiation levels in order to provide data for warning, and consequentially the assessment of a nuclear event. A network of radiation measuring equipment consisting of gamma, neutron, alpha, and beta counters would be distributed over a large area (preferably on fire station roof tops) and connected by a wireless network to the emergency response center. The networks would be deployed in urban environments and would supply first responders and federal augmentation teams (including those from the U.S. Departments of Energy, Defense, Justice, and Homeland Security) with detailed, accurate information regarding the transport of radioactive environmental contaminants, so the agencies can provide a safe and effective response. A networked sensor capability would be developed, with fixed sensors deployed at key locations and in sufficient numbers, to provide adequate coverage for early warning, and input to post-event emergency response. An overall system description and specification will be provided, including detector characteristics, communication protocols, infrastructure and maintenance requirements, and operation procedures. The system/network can be designed for a specifically identified urban area, or for a general urban area scalable to cities of specified size. Data collected via the network will be transmitted directly to the appropriate emergency response center and shared with multiple agencies via the Internet or an Intranet. The data collected will be managed using commercial off - the - shelf Geographical Information System (GIS). The data will be stored in a database and the GIS software will aid in analysis and management of the data. Unique features of the system include each node being assigned a health-effect based risk factor. By connecting the nodes on a particular measured isopleth one can define the plume accurately. Radon counts will be provided and used to calculate the alpha counts. The radiological data collected will also be of value under routine conditions, in the absence of a radiological threat, to provide a detailed map of radiation background in the urban environment and complement predictive models of radiation transport. The data can be transferred to the National Atmospheric Release Advisory Center (NARAC) to augment its predictive model, thereby increasing its fidelity. Initially, as a proof of concept, a few nodes will be built for the purpose of demonstrating the concept.

Proceedings Article | 26 October 2004 Paper

Paper

Dual glass sensor in a mixed gamma and neutron radiation field

Sanjoy Mukhopadhyay, Eric Schmidthuber, Khy Senh

Proceedings Volume 5541, (2004) https://doi.org/10.1117/12.559589

KEYWORDS: Glasses, Lithium, Sensors, Particles, Scintillators, Gamma radiation, Prototyping, LCDs, Doping, Cesium

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Proceedings Article | 20 January 2004 Paper

Paper

Plastic gamma sensors: an application in detection of radioisotopes

Sanjoy Mukhopadhyay

Proceedings Volume 5198, (2004) https://doi.org/10.1117/12.506855

KEYWORDS: Scintillators, Sensors, Gamma radiation, Energy efficiency, Particles, Scintillation, Electrons, Radioisotopes, Absorption, Solids

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Proceedings Article | 20 January 2004 Paper

Paper

Portable gamma and thermal neutron detector using 6LiI(Eu) crystals

Sanjoy Mukhopadhyay, Harold McHugh

Proceedings Volume 5198, (2004) https://doi.org/10.1117/12.506870

KEYWORDS: Sensors, Lithium, Crystals, Glasses, Gamma radiation, Helium, Energy efficiency, Scintillators, Linear filtering, Monte Carlo methods

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Showing 5 of 39 publications

Conference Committee Involvement (13)

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXVI

19 August 2024 | San Diego, California, United States

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXV

21 August 2023 | San Diego, California, United States

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXIV

22 August 2022 | San Diego, California, United States

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXIII

1 August 2021 | San Diego, California, United States

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXII

25 August 2020 | Online Only, California, United States

Showing 5 of 13 Conference Committees

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