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Advanced High-Speed 16-Bit Digitizer System

Description: The fastest commercially available 16-bit ADC can only perform around 200 mega-samples per second (200 MS/s). Connecting ADC chips together in eight different time domains increases the quantity of samples taken by a factor of eight. This method of interleaving requires that the input signal being sampled is split into eight identical signals and arrives at each ADC chip at the same point in time. The splitting of the input signal is performed in the analog front end containing a wideband filter that impedance matches the input signal to the ADC chips. Each ADC uses a clock to tell it when to perform a conversion. Using eight unique clocks spaced in 45-degree increments is the method used to time shift when each ADC chip performs its conversion. Given that this control clock is a fixed frequency, the clock phase shifting is accomplished by tightly controlling the distance that the clock must travel, resulting in a time delay. The interleaved ADC chips will now generate digital data in eight different time domains. These data are processed inside a field-programmable gate array (FPGA) to move the data back into a single time domain and store it into memory. The FPGA also contains a Nios II processor that provides system control and data retrieval via Ethernet.
Date: May 1, 2012
Partner: UNT Libraries Government Documents Department

Site-Directed Research and Development FY 2012 Annual Report

Description: The reports included in this report are for project activities that occurred from October 2011 through September 2012. These reports describe in detail the discoveries, achievements, and challenges encountered by our talented and enthusiastic principal investigators (PIs). Many of the reports describe R&D efforts that were “successful” in their pursuits and resulted in a positive outcome or technology realization. As we’ve stated before, and continue to stress, in some cases the result is a “negative” finding, for instance a technology is currently impractical or out of reach. This can often be viewed erroneously as a “failure,” but is actually a valid outcome in the pursuit of high-risk research, which often leads to unforeseen new paths of discovery. Either result advances our knowledge and increases our ability to identify solutions and/or likewise avoid costly paths not appropriate for the challenges presented. The SDRD program continues to provide an unfettered mechanism for innovation and development that returns multifold to the NNSS mission. Overall the program is a strong R&D innovation engine, benefited by an enhanced mission, committed resources, and sound competitiveness to yield maximum benefit. The 23 projects described exemplify the creativity and ability of a diverse scientific and engineering talent base. The efforts also showcase an impressive capability and resource that can be brought to find solutions to a broad array of technology needs and applications relevant to the NNSS mission and national security.
Date: April 1, 2013
Partner: UNT Libraries Government Documents Department

Evaluation of Portable X-Ray Fluorescence (XRF) Analyzer for Zirconium-Thickness Measurements

Description: This Technical Evaluation Report provides details of preliminary testing/experiments performed using a handheld X-ray fluorescence analyzer. The analyzer will be utilized in upcoming fuel-foil-rolling optimization studies at the INL. The studies are being performed in support of DOE’s Office of Global Threat Reduction -- Reactor Conversion Subprogram. Details of the equipment used, operating parameters, and measurement results are provided in this report.
Date: September 1, 2013
Creator: Moore, Glenn
Partner: UNT Libraries Government Documents Department

A National Tracking Center for Monitoring Shipments of HEU, MOX, and Spent Nuclear Fuel: How do we implement?

Description: Nuclear material safeguards specialists and instrument developers at US Department of Energy (USDOE) National Laboratories in the United States, sponsored by the National Nuclear Security Administration (NNSA) Office of NA-24, have been developing devices to monitor shipments of UF6 cylinders and other radioactive materials , . Tracking devices are being developed that are capable of monitoring shipments of valuable radioactive materials in real time, using the Global Positioning System (GPS). We envision that such devices will be extremely useful, if not essential, for monitoring the shipment of these important cargoes of nuclear material, including highly-enriched uranium (HEU), mixed plutonium/uranium oxide (MOX), spent nuclear fuel, and, potentially, other large radioactive sources. To ensure nuclear material security and safeguards, it is extremely important to track these materials because they contain so-called “direct-use material” which is material that if diverted and processed could potentially be used to develop clandestine nuclear weapons . Large sources could be used for a dirty bomb also known as a radioactive dispersal device (RDD). For that matter, any interdiction by an adversary regardless of intent demands a rapid response. To make the fullest use of such tracking devices, we propose a National Tracking Center. This paper describes what the attributes of such a center would be and how it could ultimately be the prototype for an International Tracking Center, possibly to be based in Vienna, at the International Atomic Energy Agency (IAEA).
Date: July 1, 2009
Creator: Schanfein, Mark
Partner: UNT Libraries Government Documents Department

IAEA Inspections for Undeclared and Declared Activities: Is a More Robust Approach Needed?

Description: The United States has long supported a strong international safeguards system and for many years has served as the foremost supplier of technology, equipment, and training to the International Atomic Energy Agency (IAEA). In doing so, it drew in many instances on DOE sponsored R&D and training that was directed towards domestic safeguards and then adapted for IAEA purposes. This was relatively straightforward because of the strong overlap between the development of nuclear material accountancy measures needed for both domestic and international purposes. Two factors have emerged that have made this strong reliance on domestic measures less and less able to be a source of support for the IAEA. One is the shift by the IAEA safeguards system towards detecting undeclared activities. The second is the shift of domestic attention away from nuclear material accountancy and towards physical protection. As a result, a gap in US sponsored R&D and training relevant to international safeguards has developed. The NNSA Next Generation Safeguards Initiative and the DOE NA-22 Safeguards R&D program are intended to help fill this gap and, thereby, permit the U.S. to remain as the pre-eminent supplier of technology for international safeguards purposes. In this context, IAEA challenges have been examined from the perspective of detecting the diversion of nuclear material from declared stocks; detecting undeclared production of nuclear material and activities at locations declared under INFCIRC/153; and detecting undeclared nuclear material and activities elsewhere in a state. Of these, the detection of undeclared nuclear material and activities is, perhaps, the IAEA’s most significant challenge. It is a challenge that even the international community finds difficult to meet because of the scope and the geographic scale of the problem, the technical constraints, the knowledge required, and the significant resources needed to deploy effective systems world-wide (e.g., satellite surveillance systems). The ...
Date: July 1, 2009
Creator: Schanfein, Mark
Partner: UNT Libraries Government Documents Department

Science and Technology Challenges for International Safeguards

Description: The science and technology challenges for international safeguards range from cutting edge physics needs to practical technology solutions for high volume data handling and analysis issues. This paper will take a narrow look at some of the predominant challenges, which include those at high throughput commercial facilities and those in the detection of undeclared facilities. It is hoped that by highlighting these areas it can encourage a concerted effort by scientific institutions and industry to provide robust cost-effective solutions.
Date: July 1, 2009
Creator: Schanfein, Mark
Partner: UNT Libraries Government Documents Department

JOINING OF BERYLLIUM-A SURVEY OF THE UNCLASSIFIED LITERATURE

Description: The unclassified literature on the joining of beryllium was surveyed and is summarized. The fields covered are fusion welding, self-welding (diffusion- or pressure-welding), and brazing. The most successful attempts in each field are outlined and other work is referenced. (aauth)
Date: June 1, 1958
Creator: Brown, N.A.
Partner: UNT Libraries Government Documents Department

AN ANNOTATED BIBLIOGRAPHY ON THE EFFECTS OF RADIATION ON HETEROGENEOUSLY CATALYZED REACTIONS AND ON CHEMISORPTION

Description: The 264 references were compiled primarily from a search of Chemical Abstracts, Nuclear Science Abstracts, and Dissertation Abstracts through December 1962. The annotations give the type of radiation, the catalysts investigated, and the test reactions used. The entries are cross-referenced, and indexes of the authors, catalysts, reactions, and type of radiation are provided. The compliation is limited to papers in which either heterogeneously catalyzed reactions, chemisorption, or the radiolysis of adsorbed substances was studied. Papers on the effects of ultraviolet light are not included. (auth)
Date: July 17, 1963
Creator: Krohn, N.A.
Partner: UNT Libraries Government Documents Department

Comparison of Ge(Li) and anti-Compton systems for measurements of environmental samples

Description: There are numerous reasons for performing environmental measurements for routine health or safety monitoring and to determine the movement of trace elements or radionuclides through our environment to man. This is often a requirement for the licensing of nuclear power reactors, as well as many other meteorological or environmental research experiments. In this paper a variety of sensitive low-level counting systems are discussed from an analyst's viewpoint, centering on a variety of Nal(Tl) and Ge(Li) gamma ray spectrometers. The coincident gamma-ray emitters are most sensitively detected through NaI(Tl) multidimensional gamma ray spectrometry, while single gamma ray emitters are very sensitively detected with Ge(Li) detector systems. NaI(Tl) detector systems are superior in general for environmental measurements. (auth)
Date: January 1, 1973
Creator: Wogman, N.A.
Partner: UNT Libraries Government Documents Department

EBT ring physics

Description: This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)
Date: April 1, 1980
Creator: Uckan, N.A. (ed.)
Partner: UNT Libraries Government Documents Department

Dosimetry methods and results for the former residents of Bikini Atoll

Description: The US Government utilized Bikini and Enewetak Atolls in the northern Marshall Islands of Micronesia for atomspheric tests of nuclear explosives in the 1940's and 1950's. The original inhabitants of these atolls were relocated prior to the tests. During the early 1970's, a small but growing population of Marshallese people reinhabited Bikini. Environmental and personnel radiological monitoring programs were begun in 1974 to ensure that doses and dose commitments received by Bikini residents remained within US Federal Radiation Council guidelines. Dramatic increases in /sup 137/Cs body burdens among the inhabitants between April 1977 and 1978 may have played a significant role in the government decision to move the 140 Bikinians in residence off of the atoll in August 1978. The average /sup 137/Cs body burden for the population was 2.3 ..mu..Ci in April 1978. Several individuals, however, exceeded the maximum permissible body burden of 3 ..mu..Ci, and some approached 6 ..mu..Ci. The resultant total dose commitment was less than 200 mrem for the average resident. The average total dose for the mean residence interval of approx. 4.5 years was about 1 rem. The sources of exposure, the probable cause of the unexpected increase in /sup 137/Cs body burdens, and the methods for calculating radionuclide intake and resultant doses are discussed. Suggestions are offered as to the implications of the most significant exposure pathways for the future inhabitation of Bikini and Enewetak. (ERB)
Date: January 1, 1979
Creator: Greenhouse, N.A.
Partner: UNT Libraries Government Documents Department

Multi-user data acquisition environment

Description: The typical data acquisition environment involves data collection and monitoring by a single user. However, in order to support experiments on the Mars facility at Lawrence Livermore National Laboratory, we have had to create a multi-user data acquisition environment where any user can control the data acquisition and several users can monitor and analyze data being collected in real time. This paper describes how we accomplished this on an HP A600 computer. It focuses on the overall system description and user communication with the tasks within the system. Our current implementation is one phase of a long-term software development project.
Date: January 1, 1983
Creator: Storch, N.A.
Partner: UNT Libraries Government Documents Department

Evaluation of an in-situ x-ray fluorescence analyzer for inorganic pollutants in sediments and water columns

Description: The applicability of an energy dispersive x-ray fluorescence spectrometer for measurement of trace elements in sediments and in water columns from Coast Guard vessels has been investigated. This investigation was conducted in both freshwater and saltwater areas and included Puget Sound, Lake Washington, Lake Union, and the ship canal in the State of Washington. The spectrometer system consisted of a solid cryogen-cooled Si(Li) detector and a /sup 109/Cd excitation source. Sediments and water columns were viewed through a 0.2 mm Be window. This study showed the feasibility of measuring trace elements at concentrations ranging from 20 to about 100 ppM. Measurements of this sensitivity with a 100 mCi /sup 109/Cd source are possible for time intervals as short as 5 minutes. This in-situ measurement capability permits the on-site mapping of pollution and avoids the problem of sediment disturbance which is inherent in the collection of grab samples of the sediment surface. Recommendations for an improved analyzer system included a detector assembly which could be towed, or allow continuous sediment surface analysis thereby recording the average composition of a large area.
Date: September 1, 1979
Creator: Wogman, N.A.
Partner: UNT Libraries Government Documents Department

Combination ring cavity and backward Raman waveguide amplifier

Description: A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO/sub 2/ laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO/sub 2/ laser pump signal for conversion to Stokes radiation.
Date: March 13, 1981
Creator: Kurnit, N.A.
Partner: UNT Libraries Government Documents Department

Preliminary studies of the biosynthesis of Austin. [Aspergillus ustus]

Description: Aspergillus ustus is one of the most prevalent fungi in the soil. There are now two reports of the occurrence of toxin-producing strains of this fungus on stored foodstuffs. In addition, strains of A. ustus have been isolated along with Penicillium species from samples of South African cheeses. All A. ustus isolates tested were judged to be highly toxic to ducklings when grown on maize meal, however, the toxins involved were not isolated. Austin is the trivial name of one of the toxins made by the fungus found on stored food. Preliminary work to studying the biosynthesis of this compound using /sup 13/C-labeled sodium acetate is reported here. The feasibility of the biosynthetic study was determined by feeding (1-/sup 14/C)-sodium acetate to A. ustus cultures. The assignments made in the /sup 13/C-nmr spectrum of Austin are shown. The lowest dilution factor obtained in (1-/sup 14/C)-sodium acetate feeding experiments was 14. This dilution factor is sufficiently low to allow a successful feeding of (1,2-/sup 13/C/sub 2/)-sodium acetate. A new metabolite of A. ustus, deacetylaustin, was isolated and identified. An alkaloid of unknown structure was also isolated from the fungus.
Date: January 1, 1979
Creator: Wicnienski, N.A.
Partner: UNT Libraries Government Documents Department

Physics design options for compact ignition experiments

Description: This paper considers the following topics: (1) physics assessments-design and engineering impact, (2) zero-dimensional confinement studies relating to physics requirements and options for ignited plasmas, classes of devices with equivalent performance, and sensitivity to variations in confinement models, and (3) one and one-half dimensional confinement studies relating to dynamic simulations, critical physics issues, startup analyses, and volt-second consumption. (MOW)
Date: January 1, 1985
Creator: Uckan, N.A.
Partner: UNT Libraries Government Documents Department