Download or read book Comparison of the Phoswich and ARSA type Detectors for Radioxenon Detection written by Rebecca Morgan Ward and published by . This book was released on 2010 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Comprehensive Nuclear Test Ban Treaty verification regime mandates atmospheric monitoring for the four radioxenon isotopes that are produced in high abundance in a nuclear explosion: [superscript 131m]Xe, [superscript 133m]Xe, [superscript 133g]Xe, and [superscript 135g]Xe. This mandate has driven the development of improved xenon detectors, including a phoswich detector, which has potential to replace the ARSA detector in the International Monitoring System. In this experiment, the four relevant radioxenon isotopes were produced through neutron activation and the phoswich detector was used to attain spectra from the gas. Spectral characteristics and resolution of the phoswich spectra were compared to an ARSA-type [beta]-[gamma] coincidence detector to perform an overall evaluation of the phoswich detector. The results indicated that spectral characteristics and resolutions for the phoswich were comparable to the ARSA-type detector, with slightly improved beta detection. As an additional test of the new detector's capabilities, a tailored spectrum designed to mimic a nuclear explosion signature was produced and analyzed with the detector.

Download or read book Preliminary Experiments with a Triple Layer Phoswich Detector for Radioxenon Detection written by and published by . This book was released on 2008 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Monitoring System (IMS) employs radiation detectors to monitor atmospheric or underground nuclear weapons tests. These detectors should be able to detect ultra low concentrations of xenon radioisotopes in the atmosphere. Exploiting the fact that the most interesting xenon radioisotopes emit a beta or conversion electron (CE) in coincidence with an X-ray or gamma-ray, these detectors have been designed and optimized to record coincidence events from the radioxenon isotopes. The IMS currently uses detection systems in which beta/CE and X-ray/gamma-ray are measured in separate detectors. Although the ARSA system is able to detect very low concentrations of radioxenon, its complexity makes the beta and gamma-ray energy calibration very difficult. Phoswich technology, accompanied by digital signal processing of photomultiplier tube (PMT) pulses, can simplify radioxenon detection. If well designed, like other current sensitive radioxenon detectors, a phoswich detector is also capable of detecting beta/gamma coincidence events using digital-pulse-shape analysis. We have designed a two-channel triple-layer phoswich detector for radioxenon detection. Each phoswich detector consists of three scintillation layers: a thin plastic (1.5mm) scintillator for detection of beta and CE, a CaF2 layer (2mm) for X-ray detection and a NaI layer (25.4mm) for gamma-ray measurement. A two-channel FPGA-based Digital Pulse Processor, DPP2.0, (250 MHz, 12 bits) has been designed and constructed for capturing and transferring valid phoswich pulses to the PC. A graphical user interface (GUI) also has been developed to control the DPP2.0, digitally analyze phoswich pulses, and reconstruct the 2-D beta/gamma coincidence spectra. In this paper, our digital pulse shape discrimination technique, the DPP2.0, and the GUI are introduced. At the end, our preliminary measurements with the prototypic phoswich detector are discussed.

Download or read book Development of a COTS Radioxenon Detector System Using Phoswich Detectors and Pulse Shape Analysis written by and published by . This book was released on 2008 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several of the radioxenon detection systems developed for the International Monitoring System use beta/gamma coincidence detection to achieve high sensitivity. These systems use an arrangement of separate beta and gamma detectors to detect beta/gamma coincidence events characteristic of the different radioxenon isotopes. While very sensitive to small amounts of radioxenon, they also require careful calibration and gain matching of several detectors and photomultiplier tubes. An alternative approach is the use of a single phoswich detector in which beta-gamma coincidences are detected by pulse shape analysis (PSA). We previously reported on prototype phoswich well detectors, consisting of a fast plastic scintillator (absorbing betas) optically coupled to a slower CsI(Tl) scintillator (absorbing gammas). These detectors require only a single photomultiplier tube and an electronics readout channel. Beta/gamma coincidences create characteristic "fast/slow" signals that can easily be distinguished from "slow only" or "fast only" non-coincident interactions. We describe the development of a commercial off-the-shelf (COTS) radioxenon detector system based on such phoswich detectors. The PSA functions were implemented using the digital signal processor in a set of commercial readout electronics that is also compatible with ARSA and SAUNA detectors. These functions detect coincidences in real time and accumulate 2D histograms in on-board memory. The acquisition and the PSA functions can also be integrated into larger-scale acquisition and control software. Several phoswich detectors have been characterized for energy resolution, separation of coincidence events in 2D beta/gamma energy histograms, and detection efficiency. A test pulser module has been developed to support monitoring and testing of the electronics for state of health during operation. The phoswich detector, readout electronics, and software are now available as a COTS product package.

Download or read book A Two Channel Phoswich Detector for Dual and Triple Coincidence Measurements of Radioxenon Isotopes written by and published by . This book was released on 2007 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the Comprehensive Nuclear Test Ban Treaty, the International Monitoring System (IMS) has been established for monitoring xenon radioisotopes in the atmosphere to detect atmospheric or underground nuclear explosions. Experimental results from the Automated Radioxenon Sampler/Analyzer (ARSA) system, developed at Pacific Northwest National Laboratory, show that the system is capable of detecting very low concentrations of the fission product radioxenon isotopes (133)Xe, (133m)Xe, (131m)Xe and (135)Xe. To build a more practical radioxenon detection system as sensitive as the ARSA system but with reduced cost, size, power consumption and complexity, several detection systems have been developed or are currently under development. It has been shown (McIntyre et al. 2004) that triple coincidence measurements of beta, conversion electons (CE) and x-ray from the radioxenon gas provides a significant reduction of Compton scatter interference in the 30-keV line and therefore much lower (2-3 orders of magnitude) concentrations of (133)Xe can be detected even with a high radon background. The triple coincidence measurement eliminates the need for additional separation columns and traps (required for removing the background radon) and allows for reduced passive shielding as well, thus reducing the size and power consumption of the system. In this paper, a two-channel phoswich detector is introduced and studied. The detector consists of a thin hollow disk (with 2 mm thickness and 76.2 mm diameter) as the xenon gas cell, surrounded by two identical planar triple-layer phoswich detectors. This design provides a solid angle of about 3.4 pi for the gas cell, close to that of the ARSA system (tilde 3.5 pi). The planar shape of the detectors has several important advantages, among which are the reduced cost due to its simplicity, and because it has a minimum non-uniformity in light collection efficiency, will not unreasonably degrade the beta or gamma energy resolution.

Download or read book Issues in Industrial Applied and Environmental Chemistry 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 4118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Industrial, Applied, and Environmental Chemistry: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Industrial, Applied, and Environmental Chemistry. The editors have built Issues in Industrial, Applied, and Environmental Chemistry: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Industrial, Applied, and Environmental Chemistry in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Industrial, Applied, and Environmental Chemistry: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book An Investigation of the Light Capture Properties of the XEPHWICH a Phoswich Radiation Detection System written by Sean E. Jones and published by . This book was released on 2009 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The XEPHWICH system is a phoswich type (multiple scintillator) radiation detector designed to detect several radioxenon isotopes with the goal of identifying covert nuclear explosions. The XEPHWICH system is designed with the sole purpose of replacing the Automated Radio-xenon Sampler/Analyzer (ARSA) in the United Nation's (UN) Comprehensive Test Ban Treaty's (CTBT) International Monitoring System (IMS). This study consists of two stages, computer simulation and laboratory experiment. The use of DETECT2000, a Monte-Carlo optical simulator, was the method by which optical performance and potential improvements to the XEPHWICH design were investigated. The laboratory experiment conducted in this study validated the modeling methods used in the study and investigated the effects of light capture efficiency on XEPHWICH system output. The experiment consisted of exposing the NaI(Tl) layer of the XEPHWICH to a lead collimated Cs-137 beam at varying locations, and comparing the differential energy spectra observed. The simulation work resulted in design considerations for improving the optical performance of the XEPHWICH. Additionally, through simulation, the optical performance of the XEPHWICH was characterized and can be compared to competing scintillator designs. The experimental observations included expected and unexpected effects that light capture properties had on the system signal. Of particular importance, the experimental results supported the modeling method applied, and demonstrated that an increase in expected light capture efficiency was associated with better energy resolution for a full energy peak in a differential pulse height spectrum.

Download or read book Improved beta gamma Coincidence Detector For Radioxenon Detection written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Automated Radio-xenon Analyzer/Sampler (ARSA), built by Pacific Northwest National Laboratory (PNNL), can collect and detect several radioxenon isotopes. ARSA is very sensitive to 133Xe, 131mXe, 133mXe and 135Xe due to the compact high efficiency coincidence detector it uses. For this reason it is an excellent treaty monitoring and environmental sampling device. Although the system is shown to be both robust and reliable, based on several field tests, it is also complex due to a detailed photomultiplier tube gain matching regime. This complexity is a problem from a maintenance and quality assurance/quality control (QA/QC) standpoint. To reduce these issues a simplified coincident detector has been developed. A comparison of three different well detectors has been completed. In addition, a new plastic scintillator gas cell was constructed. The new simplified detector system has been demonstrated to equal or better performance compared with the original ARSA design in spectral resolution and efficiency and significantly easier to setup and calibrate.

Download or read book A Multi Layer Phoswich Radioxenon Detection System written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory radioactive sources were used to characterize the phoswich detector. The CaF2 scintillator has a low light-yield and slow decay time, thus produces very small signals due to low-energy gamma rays or X-rays. Therefore, detection of 30 keV X-rays (from the xenon radioisotopes) using this layer and discriminating its very small signals from electronic noise was a challenging task. Several solutions were considered and experimentally evaluated. We found that the best solution would be extending the fast triangular filter from 10 taps to 30 taps. This will extend the peaking time of this filter from 25 nsec to 75 nsec. The digital filter is implemented in FPGA on our DPP2.0 and is used to trigger the detection system. Functionality of the new filter in capturing and discriminating 30 keV X-rays was confirmed by using a 133Ba gamma-ray source. Development of the DPP GUI software has continued with the addition of two new panels to display histograms of beta/gamma and beta/x-ray coincidence events. This includes coincidence events from a single channel, as well as two-channel, coincidence event. A pileup rejection algorithm has been implemented in the FPGA code, and controls to adjust its sensitivity have been added to the GUI. Work has begun on a new prototype system to develop a USB host interface between the PC and the FPGA to end reliance on Opal Kelly prototyping boards; the hardware for this system has been completely assembled, and the PC-side software is currently in development.

Download or read book Triple Coincidence Radioxenon Detector written by Paul L. Reeder and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Automated Radioxenon Sampler/Analyzer (ARSA) built by Pacific Northwest National Laboratory (PNNL) is on e of the world's most sensitive systems for monitoring the four radioxenon isotopes 133Xe, 133mXE, 131mXe and 135Xe. However, due to size, weight and power specifications appropriate to meet treaty-monitoring requirements; the ARSA is unsuitable for rapid deployment using modest transportation means. To transition this technology to a portable unit can be easily and rapidly deployed can be achieved by significant reductions in size, weight and power consumption if concentration were not required. As part of an exploratory effort to reduce both the size of the air sample and the gas processing requirement PNNL has developed an experimental nuclear detector to test and qualify the use of triple coincidence signatures (beta, conversion electron, x-ray) from two of the radioxenon isotopes (135Xe and 133Xe) as well as the more traditional beta-gamma coincidence signatures used by the ARSA system. The additional coincidence requirement allows for reduced passive shielding, and makes it possible for unambiguous detection of 133Xe and 153Xe in the presence of high 222Rn backgrounds. This paper will discuss the experimental setup and the results obtained for a 133Xe sample with and without 222Rn as an interference signature.

Download or read book Handbook of Radioactivity Analysis written by Michael F. L'Annunziata and published by Academic Press. This book was released on 2020-03-07 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Radioactivity Analysis: Radiation Physics and Detectors, Volume One, and Radioanalytical Applications, Volume Two, Fourth Edition, constitute an authoritative reference on the principles, practical techniques and procedures for the accurate measurement of radioactivity - everything from the very low levels encountered in the environment, to higher levels measured in radioisotope research, clinical laboratories, biological sciences, radionuclide standardization, nuclear medicine, nuclear power, and fuel cycle facilities, and in the implementation of nuclear forensic analysis and nuclear safeguards. It includes sample preparation techniques for all types of matrices found in the environment, including soil, water, air, plant matter and animal tissue, and surface swipes.Users will find the latest advances in the applications of radioactivity analysis across various fields, including environmental monitoring, radiochemical standardization, high-resolution beta imaging, automated radiochemical separation, nuclear forensics, and more. - Spans two volumes, Radiation Physics and Detectors and Radioanalytical Applications - Includes a new chapter on the analysis of environmental radionuclides - Provides the latest advances in the applications of liquid and solid scintillation analysis, alpha- and gamma spectrometry, mass spectrometric analysis, Cherenkov counting, flow-cell radionuclide analysis, radionuclide standardization, aerosol analysis, high-resolution beta imaging techniques, analytical techniques in nuclear forensics, and nuclear safeguards - Describes the timesaving techniques of computer-controlled automatic separation and activity analysis of radionuclides - Provides an extensive table of the radiation characteristics of most radionuclides of interest for the radioanalytical chemist

Download or read book Nuclear Principles in Engineering written by Tatjana Jevremovic and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear engineering plays an important role in various industrial, health care, and energy processes. Modern physics has generated its fundamental principles. A growing number of students and practicing engineers need updated material to access the technical language and content of nuclear principles. "Nuclear Principles in Engineering, Second Edition" is written for students, engineers, physicians and scientists who need up-to-date information in basic nuclear concepts and calculation methods using numerous examples and illustrative computer application areas. This new edition features a modern graphical interpretation of the phenomena described in the book fused with the results from research and new applications of nuclear engineering, including but not limited to nuclear engineering, power engineering, homeland security, health physics, radiation treatment and imaging, radiation shielding systems, aerospace and propulsion engineering, and power production propulsion.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radionuclides in the Environment written by David A. Atwood and published by John Wiley & Sons. This book was released on 2013-02-19 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear energy is the one energy source that could meet the world's growing energy needs and provide a smooth transition from fossil fuels to renewable energy in the coming decades and centuries. It is becoming abundantly clear that an increase in nuclear energy capacity will, and probably must, take place. However, nuclear energy and the use of radionuclides for civilian and military purposes lead to extremely long-lived waste that is costly and highly problematic to deal with. Therefore, it is critically important ot understand the environmental implications of radionuclides for ecosystems and human health if nuclear energy is to be used to avoid the impending global energy crisis. The present volume of the EIC Books series addresses this critical need by providing fundamental information on environmentally significant radionuclides. The content of this book was developed in collaboration with many of the authors of the chapters. Given the enormity of the subject the Editor and the Authors had to be judicious in selecting the chapters that would appropriately encompass and describe the primary topics, particularly those that are of importance to the health of ecosystems and humans. The resulting chapters were chosen to provide this information in a book of useful and appropriate length. Each chapter provides fundamental information on the chemistry of the radionuclides, their occurrence and movement in the enivornment, separation and analyses, and the technologies needed for their remediation and mitigation. The chapters are structured with a common, systematic format in order to facilitate comparions between elements and groups of elements. About EIC Books The Encyclopedia of Inorganic Chemistry (EIC) has proved to be one of the defining standards in inorganic chemistry, and most chemistry libraries around the world have access either to the first of second print editon, or to the online version. Many readers, however, prefer to have more concise thematic volumes, targeted to their specific area of interest. This feedback from EIC readers has encouraged the Editors to plan a series of EIC Books, focusing on topics of current interest. They will appear on a regular basis, and will feature leading scholars in their fields. Like the Encyclopedia, EIC Books aims to provide both the starting research student and the confirmed research worker with a critical distillation of the leading concepts in inorganic and bioinorganic chemistry, and provide a structured entry into the fields covered. This volume is also available as part of Encyclopedia of Inorganic Chemistry, 5 Volume Set. This set combines all volumes published as EIC Books from 2007 to 2010, representing areas of key developments in the field of inorganic chemistry published in the Encyclopedia of Inorganic Chemistry. Find out more.

Download or read book Monitoring a Comprehensive Test Ban Treaty written by Eystein S. Husebye and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international treaty banning the testing of any nuclear device in any environment - a comprehensive test ban treaty (CTBT) - has been on the political agenda for nearly 40 years. Objections to a CTBT have been political, technical, or a combination of both. However, the possibilities seem better after the end of the Cold War. In the prevailing, cooperative disarmament climate a CTBT appears likely to be approved by most countries in 1996. Hence the great current interest in monitoring technologies and capabilities. Such issues are comprehensively addressed here, a preamble being devoted to the political developments and setbacks over the past 40 years. Since seismic means are considered the dominant monitoring element, they are explored in detail. Contributions cover network deployments, advanced signal processing, wave propagation in heterogeneous media, and seismic source representations, and a variety of techniques for source classification (including neural networks). Complementary monitoring techniques, such as hydroacoustics, radionuclides and infrasound, are also summarised. The IAEA operation for monitoring compliance with the Non-Proliferation Treaty is also presented. The book also includes eyewitness accounts of the Soviet 50 Mt megabomb development and test, as well as the efforts made by the state to monitor the nuclear test programmes of the western powers. Includes some 33 articles written by distinguished scientists active in CTBT monitoring research for decades.

Download or read book Nuclear Test Ban written by Ola Dahlman and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear tests have caused public concern ever since the first such test was conducted, more than six decades ago. During the Cold War, however, con- tions were not conducive to discussing a complete ban on nuclear testing. It was not until 1993 that negotiations on such a treaty finally got under way. From then on, things moved relatively quickly: in 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To date, the Treaty has been signed by 178 states and ratified by 144, though it has yet to enter into force, as nine out of 44 ‘‘Annex 2 states’’, whose ratification is mandatory, have not heeded the call. Nevertheless, the CTBT verification system is already provisionally operational and has proven its effectiveness. We commend the CTBT organisation in Vienna for its successful efforts to build a verification network. This book is an excellent overview of the evolution of the CTBT and its verification regime. The authors are eminent scholars from the Netherlands, Norway and Sweden who have been intimately involved with the CTBT and its verification agency, the CTBTO Preparatory Commission, from their inc- tion to the present day. They have written a thorough and engaging narrative of the long road that led to the CTBT. Their story will appeal to both the layman and the expert and provide useful lessons for future negotiations on disarmament issues.

Download or read book Analysis of Environmental Radionuclides written by Pavel P. Povinec and published by Elsevier. This book was released on 2011-07-28 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to present a state of art summary of current knowledge of methods of assessment of radionuclides in the terrestrial and marine environments. It cover the traditional methods of radioactivity measurements such as radiometrics techniques, but also recent developments in the mass spectrometry sector. The book starts with a short preface introducing the subject of the book, summarising content and philosophy of the book, as well as the most important historical achievements. The scientific topics are introduced by description of sampling methods, optimisation of sampling sites and sampling frequency. The recent developments in radiochemical separation methods using chromatography resins for the treatment of actinides, transuranics and other groups of radioelements are also described. No other book is available covering all aspects of environmental radioactivity measurements, although remarkable progress has been made in detection techniques over the last ten years. At present the new methods enable to carry out investigations which were not possible before, either because of lack of sensitivity or because of the fact that they required too large samples.

Download or read book Alvarez Adventures of a Physicist written by Luis W. Alvarez and published by Plunkett Lake Press. This book was released on 2019-08-08 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: During World War II, Luis W. Alvarez participated in the Allies’ development of radar at the MIT Radiation Laboratory, and of the atomic bomb at Los Alamos. He then worked as an experimental physicist on cyclotrons, particle accelerators and bubble chambers at UC-Berkeley with Ernest Lawrence. Later in life, he used cosmic rays to “X ray” an Egyptian pyramid, developed a new theory about the extinction of the dinosaurs, and won the 1968 Nobel prize in physics for his work on elementary particles. In this autobiography, Alvarez shares insights on the process of scientific discovery, risk-taking in science and how theoretical and experimental physics interact. “[A] delightful autobiography... [A] fascinating book... It should be read by everyone who is interested in science and adventure, or who just wants to meet one of our most fascinating contemporaries.” — James Trefil, New York Times Book Review “Beyond its self-portrait, Alvarez provides an exceptionally clear view of the world of science.” — Alan Lightman, Washington Post Book World “This is a richly absorbing autobiography... Personally as well as scientifically forthright and plainspoken, [Alvarez] holds the reader with the story of his life as a scientist, much of the time at Berkeley, Calif., working with such men as Robert Oppenheimer, Ernest Lawrence and Enrico Fermi.” — Publishers Weekly “A gripping book. It succeeds well in making the scientific experience and the excitement of discovery accessible to the general reader.” — Richard L. Garwin,Physics Today “A fascinating life.” — Elena Brunet, Los Angeles Times “One of the best popular books on science to emerge from the laboratory in years.” — Henry Kisor, Chicago Sun-Times “Luis W. Alvarez has an unsurpassed reputation among scientists for a lifelong record of crucial participation in important discoveries in pure and applied science. In this book he performs an additional service by revealing his thought processes.” — Philip Abelson, Science Advisor, American Association for the Advancement of Science