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13,288 Matching Results
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The response of survey meters to pulsed radiation fields
The response of most survey meters to steady radiation fields is fairly well known and documented. However, hardly any data is available in the literature regarding the response of these instruments to pulsed radiation. Pulsed radiation fields are encountered, e.g., in the vicinity of linear electron accelerators or klystrons. An instrument that ordinarily responds well to the average dose rate spread out evenly in time may not be able to cope with such a high dose rate. Instruments which have long dead times such as Geiger Mueller and proportional counters tend to become saturated in such fields and only count repetition rate. Ionization chambers are less influenced, however, they must be operated with adequate voltage to overcome recombination losses. Scintillation survey meters may become non-linear at higher dose rates for pulsed radiation because the photomultiplier cannot handle the instantaneous currents that are required. Because of the need to test the response of different radiation detection instruments to pulsed fields, a pulsed x-ray facility has been built (I/sub p/87). A brief description of this facility is given along with tests of several different instruments. 5 refs., 4 figs., 1 tab.
Date:
November 1, 1987
Creator:
McCall, R.C. & Ipe, N.E.
Object Type:
Article
System:
The UNT Digital Library
Systems studies on the extraction of uranium from seawater
This report summarizes the work done at MIT during FY 1981 on the overall system design of a uranium-from-seawater facility. It consists of a sequence of seven major chapters, each of which was originally prepared as a stand-alone internal progress report. These chapters trace the historical progression of the MIT effort, from an early concern with scoping calculations to define the practical boundaries of a design envelope, as constrained by elementary economic and energy balance considerations, through a parallel evaluation of actively-pumped and passive current-driven concepts, and thence to quantification of the features of a second generation system based on a shipboard-mounted, actively-pumped concept designed around the use of thin beds of powdered ion exchange resin supported by cloth fiber cylinders (similar to the baghouse flyash filters used on power station offgas). An assessment of the apparently inherent limitations of even thin settled-bed sorber media then led to selection of an expanded bed (in the form of an ion exchange wool), which would permit an order of magnitude increase in flow loading, as a desirable advance. Thus the final two chapters evaluate ways in which this approach could be implemented, and the resulting performance levels which could be attained. Overall, …
Date:
November 1, 1981
Creator:
Driscoll, M.J. & Best, F.R.
Object Type:
Report
System:
The UNT Digital Library
Neutron yield of medical electron accelerators
Shielding calculations for medical electron accelerators above about 10 MeV require some knowledge of the neutron emission from the machine. This knowledge might come from the manufacturer's specifications or from published measurements of the neutron leakage of that particular model and energy of accelerator. In principle, the yield can be calculated if details of the accelerator design are known. These details are often not available because the manufacturer considers them proprietary. A broader knowledge of neutron emission would be useful and it is the purpose of this paper to present such information. 5 refs., 1 tab.
Date:
November 1, 1987
Creator:
McCall, R.C.
Object Type:
Article
System:
The UNT Digital Library
SLAC linear collider: the machine, the physics, and the future
The SLAC linear collider, in which beams of electrons and positrons are accelerated simultaneously, is described. Specifications of the proposed system are given, with calculated preditions of performance. New areas of research made possible by energies in the TeV range are discussed. (GHT)
Date:
November 1, 1981
Creator:
Richter, B.
Object Type:
Article
System:
The UNT Digital Library
MHD generator component development. Quarterly report, July 1983-September 1983
The overall objectives of this program are two-fold: (1) To contribute, by appropriate systematic experimental and analytical investigations, to the engineering data base necessary for the design and construction of MHD generators at CDIF-scale (50 MW/sub th/) and baseload scale (2000 MW/sub th/). (2) To design and fabricate specific hardware items to be tested at the CDIF site in Butte, Montana. The program consists of a series of related tasks: (1) MHD channel design and performance; (2) MHD channel construction and lifetime; (3) MHD channel loading and control; (4) facility operation; (5) CDIF related hardware; and (6) high interaction tests of a supersonic channel. Progress is reported. (WHK)
Date:
November 1, 1983
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Results of the radiological survey at 105 Garibaldi Avenue, Lodi, New Jersey (LJ065)
Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 105 Garibaldi Avenue, Lodi, New Jersey (LJ065), was conducted during 1987. 4 refs., 4 figs., 3 tabs.
Date:
November 1, 1989
Creator:
Foley, R.D.; Floyd, L.M. & Carrier, R.F.
Object Type:
Report
System:
The UNT Digital Library
Study of the macrozooplankton within the samples taken at the Mobile site from November 1977 through November 1978. A data report of the Lawrence Berkeley Laboratory
This report brings together the results of a re-examination of zooplankton samples from the Mobile OTEC site (29/sup 0/N-88/sup 0/W) in the northern Gulf of Mexico for macrozooplankton larger than 15 mm.
Date:
November 1, 1981
Creator:
Steen, J. & Gunter, G.
Object Type:
Report
System:
The UNT Digital Library
An evaluated neutronic data file for bismuth
A comprehensive evaluated neutronic data file for bismuth, extending from 10{sup {minus}5} eV to 20.0 MeV, is described. The experimental database, the application of the theoretical models, and the evaluation rationale are outlined. Attention is given to uncertainty specification, and comparisons are made with the prior ENDF/B-V evaluation. The corresponding numerical file, in ENDF/B-VI format, has been transmitted to the National Nuclear Data Center, Brookhaven National Laboratory. 106 refs., 10 figs., 6 tabs.
Date:
November 1, 1989
Creator:
Guenther, P. T.; Lawson, R. D.; Meadows, J. W.; Smith, A. B.; Smith, D. L.; Sugimoto, M. et al.
Object Type:
Report
System:
The UNT Digital Library
Possibilities for x-ray holography using synchrotron radiation
Since the theoretical and experimental demonstrations of the effectiveness of soft x-rays in imaging biological material there has been considerable study given to the prospects for further development of the presently existing techniques. This has been motivated to a large extent by advances in source technology, particularly the use of undulators on electron storage rings and recent improvements in short wavelength lasers. The present author has carried out theoretical evaluations of the possibilities of holographic imaging and has also recorded a number of holograms using the U15 soft x-ray beamline at the National Synchrotron Light Source (NSLS) 750 MeV storage ring at Brookhaven. Some of these have been successfully reconstructed using He:Cd laser light. In this paper we first review the physical processes which generate information containing wavefronts when soft x-rays interact with matter. We then briefly describe the holographic method which has been highly developed using visible light lasers and identify holographic geometries which are promising for x-ray applications. We discuss some of the practical and theoretical limitations involved in making holographic images and then give the results of our own experiments.
Date:
November 1, 1983
Creator:
Howells, M.R.
Object Type:
Report
System:
The UNT Digital Library
Patterns of United States mortality for ten selected causes of death
Income, ethnicity, education, and occupation are examples of socio-economic factors associated with the occurrence of disease, whether an investigation focuses on an individual or on an aggregation of individuals. In this study, data aggregated to the county level are used to explore two issues - geographic variation and geographic covariation of ten selected causes of death in the United States. The counties of the United States are characterized by 15 socio-economic variables and age-adjusted mortality rates for the ten selected causes of death. The observed variation among the US counties, as measured by the socio-economic variables, is first assessed, then the geographic variation and covariation are described for each cause of death and, finally, the covariation among causes of death is analyzed after adjusting for the influences of the measured sources of county variation.
Date:
November 6, 1980
Creator:
Selvin, S.; Sacks, S.T. & Merrill, D.W.
Object Type:
Report
System:
The UNT Digital Library
Calculated concentrations of any radionuclide deposited on the ground by release from underground nuclear detonations, tests of nuclear rockets, and tests of nuclear ramjet engines
This report presents calculated gamma radiation exposure rates and ground deposition of related radionuclides resulting from three types of event that deposited detectable radioactivity outside the Nevada Test Site complex, namely, underground nuclear detonations, tests of nuclear rocket engines and tests of nuclear ramjet engines.
Date:
November 1, 1981
Creator:
Hicks, H.G.
Object Type:
Report
System:
The UNT Digital Library
Results of the radiological survey at 112 Columbia Lane, Lodi, New Jersey (LJ068)
Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 112 Columbia Lane, Lodi, New Jersey (LJ068), was conducted during 1987. 4 refs., 6 figs., 3 tabs.
Date:
November 1, 1989
Creator:
Foley, R.D.; Floyd, L.M. & Carrier, R.F.
Object Type:
Report
System:
The UNT Digital Library
Stable Auroral Red arc occurrences detected by the Pacific Northwest Laboratory photometer network: A decade of observations, 1978--1988
Using data obtained from a network of all-sky scanning photometers designed to operate routinely for long periods of time, a comprehensive inspection of observations covering the time period 1978--1988 has revealed features that we interpret to be Stable Auroral Red (SAR) arcs during 250 nighttime observing periods. These arcs result from high temperature within the ionospheric electron gas that is maintained by slow leakage of energy from the earth's magnetosphere. A listing of these events, the most complete available for this time interval, is presented for the purpose of complementing observations reported for earlier dates. This listing is composed of location of the observing photometer, date, time, photometric intensity, and location (as defined by the earth's magnetic coordinate system). The intent is to make these observations available to a broad range of researchers and thereby initiate further investigations of these features. 22 refs., 3 figs., 2 tabs.
Date:
November 1, 1989
Creator:
Slater, D. W. & Kleckner, E. W.
Object Type:
Report
System:
The UNT Digital Library
Considerations involved in the design of negative-ion-based neutral beam systems
We consider the requirements and constraints for negative-ion-based neutral beam injection systems, and show how these are reflected in design considerations. We will attempt to develop a set of guidelines for users and developers to use to see how well (in a qualitative sense, at least) a particular neutral beam system fits a particular proposed need.
Date:
November 1, 1983
Creator:
Cooper, W. S.
Object Type:
Article
System:
The UNT Digital Library
Electroformation of uranium hemispherical shells
This effort was directed at developing an electrochemical process for forming uniform and dendrite-free deposits of uranium from molten salts. This process is to be used for the electroformation of free-standing hemispherical shells of uranium for nuclear applications. Electrodeposition of uranium onto a substrate was accomplished with a fused chloride mixture containing 42 wt% UCl{sub 3} and a fused chloride-fluoride mixture containing 4 wt % UF{sub 4}. Under pulsed potential control at 504{degree}C, the chloride-fluoride mixture yielded the widest range of plating conditions for which dendrites could be avoided. Bipolar current pulse plating with both electrolytes gave good results, and successful application of this technique to a large tubular cathode has been demonstrated. 24 refs., 10 figs.
Date:
November 1, 1989
Creator:
Marshall, S.L.; Redey, L.; Vandegrift, G.F. & Vissers, D.R.
Object Type:
Report
System:
The UNT Digital Library
Heavy ion fusion year-end report, April 1, 1983-September 30, 1983
Some highlights of the program during this reporting period are as follows: (1) First results with the completed apparatus of the Single Beam Transport Experiment (SBTE) have shown the stable propagation of a space-charge-dominated cesium-ion beam through 41 periods of an AG focussing lattice. The space-charge effects were large enough to depress the betatron phase advance per cell from sigma/sub 0/ = 60/sup 0/ to sigma = 12/sup 0/. (2) Understanding of the reflection stabilization of longitudinal instability in a high-current beam bunch has been improved by analytical and computational studies. (3) Conceptual design studies of a multiple-beam ion induction linac suitable for the High Temperature Experiment have progressed to the stage where a first reference design (sodium, 125 MeV, 30 ..mu..C, 16 beams) is available. (4) The Long-Pulse Induction Accelerating Unit, first used to accelerate a cesium-ion beam in February 1983, has been undergoing modification in the low-level trigger circuitry to allow more precisely controlled waveform synthesis.
Date:
November 1, 1983
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Devitrification behavior of SRL defense waste glass
Simulated SRL waste was prepared with compositions varying in iron and aluminum content. Two batches with similar composition were produced with different amounts of reducing agent added. Samples were isothermally heat treated and used to derive time-temperature-transformation diagrams. Supplementary samples were cooled in a manner programmed to simulate the cooling curves of production canisters. Less than 10% total devitrification occurs during normal processing. However, when waste glass 165 was purposely devitrified, up to 30 volume percent total spinel and acmite formed. Formation of these species had minor effect on leachability in MCC-1 and accelerated leach tests. 20 references, 4 figures, 2 tables.
Date:
November 1, 1983
Creator:
Bickford, Dennis F. & Jantzen, Carol M.
Object Type:
Article
System:
The UNT Digital Library
Increasing the Life of Cutting Fluids Used in the LLNL Machine Shop
The objective of this study was to extend the working life of cutting fluids used in metal machining operations at LLNL. The characteristics of the fluids in nine different machines were studied. The pH, bacteria level, percent coolant concentrate, percent tramp oil, and total undissolved solids were monitored on a week-to-week basis for 6 weeks. During this time, the criteria and procedures used for changing the cutting fluids in the machines were also observed. Although the study is incomplete, the following recommendations were made. Cutting fluids should be diluted with deionized water and the concentration of the cutting fluid should be monitored regularly with a refractometer. A bactericide should be added to the cutting fluid. The machines should have a thorough initial cleaning and machine oil leaks should be eliminated. Only one cutting fluid should be used throughout the shop. Methods for removing metal particles from used cutting oils should be investigated. (LCL)
Date:
November 18, 1981
Creator:
Cadena, C. A.; da Roza, R. A.; Johnson, J. S. & Szidon, R. D.
Object Type:
Report
System:
The UNT Digital Library
Hot-gas cleanup system model development. Volume II. Final report
Under Contract to the Department of Energy (DOE) through the Morgantown Energy Technology Center (METC), Flow Industries, Inc., has developed computer models to simulate the physical performance of five hot-gas cleanup devices for pressurized, fluidized-bed combustion (PFBC), combined-cycle power plants. Separate cost models have also been developed to estimate the cost of each device. The work leading to the development of these models is described in Volume I of this report. This volume contains the user's manuals for both the physical and cost models. The manuals for the physical models are given first followed by those for the cost models. Each manual is a complete and separate document. The model names and devices and their respective subroutine names are: (1) Moving Granular Bed Filter by Combustion Power Company, USRCGB, QFCOST; (2) Ceramic Bag Filter by Acurex, USRACB, QDCOST; (3) Electrostatic Granular Bed Filter by General Electric, USRGGB, QACOST; (4) Electrostatic Precipitator by Research Cottrell, USRCEP, QECOST; and (5) Electrocyclone by General Electric, USRGCY, QBCOST.
Date:
November 1, 1982
Creator:
Ushimaru, K.; Bennett, A. & Bekowies, P.J.
Object Type:
Report
System:
The UNT Digital Library
Magnetic interactions in sup 119 Sn substituted for Cu in antiferromagnetic and superconducting lamellar cuprates
Moessbauer Spectroscopy (MS) studies of {sup 119}Sn were carried out in antiferromagnetic La{sub 2}(Cu{sub 0.99}Sn{sub 0.01})O{sub 4} (214) and in superconducting GdBa{sub 2}(Cu{sub 0.99}Sn{sub 0. 01}){sub 3}O{sub 7} (123). Non-magnetic Sn{sup 4+} substitutes for Cu if the right procedure for diffusing {sup 119}SnO{sub 2} in CuO is carried out. Studies performed in 214 show a large quadrupole splitting (QS) down to 120 K followed by an onset of a magnetic interaction reaching a saturation internal field of H{sub eff} = 8.7(5) KOe at T = 30 K. From the combined magnetic-quadrupole interaction the angle {theta} formed by q{sub zz} and H{sub eff}, the {eta}-parameter, and the sign of QS were deduced and information on the local spin structure is derived. Studies conducted with the 123 material (T{sub c} = 90 K) reveal a broad unsplit line at temperatures down to 60 K followed by an abrupt onset of a magnetic interaction corresponding to H{sub eff} (Sn) = 8.3 (7) KOe. The hyperfine field decreases with decreasing temperature reaching 6.0(1) KOe at 16 K. The onset of the magnetic interaction at the {sup 119}Sn nucleus is explained as due to a local depletion of holes following the Sn{sup 4+} doping and …
Date:
November 9, 1989
Creator:
Pasternak, M. & Taylor, R. D.
Object Type:
Article
System:
The UNT Digital Library
Influence of cover defects on the attenuation of radon with earthen covers
Experimental and theoretical evaluations of radon flux through laboratory-scale defective soil columns are presented together with a survey of literature on the formation and prevention of defects in soil covers. This report focuses on air-filled, centimeter-scale defects that are most probable in earthen covers for attenuating radon emission from uranium-mill tailings. Examples include shirnkage and erosion cracks, erosion piping, animal burrows and air channels formed by the biodegradation of vegetation roots. Calculations based on mathematical models indicate that collections of defects which could increase the radon flux from an earthen cover by a factor of two would be easily detected by visual inspection. However, these models ignore air-turbulence in the defect and drying of the soil around the defect. Laboratory measurements showed that turbulent diffusion of radon occurred through defects as narrow as 0.3 cm when subjected to a transverse air velocity of 1 to 6 miles per hour at the surface. Both turbulence and more-rapid drying of soil can accelerate radon flux to the cover surface. Consequently, recommended methods to inhibit defect formation should be applied. 29 references, 3 figures, 5 tables.
Date:
November 1, 1983
Creator:
Kalkwarf, D. R. & Mayer, D. W.
Object Type:
Report
System:
The UNT Digital Library
Hanford protective barriers program: Status of asphalt barrier studies - FY 1989
The Hanford Protective Barrier Program is evaluating alternate barriers to provide a means of meeting stringent water infiltration requirements. One type of alternate barrier being considered is an asphalt-based layer, 1.3 to 15 cm thick. Evaluations of these barriers were initiated in FY 1988, and, based on laboratory studies, two asphalt formulations were selected for further testing in small-tube lysimeters: a hot rubberized asphalt and an admixture of cationic asphalt emulsion and concrete sand containing 24 wt% residual asphalt. Eight lysimeters containing asphalt seals were installed as part of the Small Tube Lysimeter Test Facility on the Hanford Site. Two control lysimeters containing Hanford sand with a surface gravel treatment were also installed for comparison. 5 refs., 13 figs., 1 tab.
Date:
November 1, 1989
Creator:
Freeman, H.D. & Gee, G.W.
Object Type:
Report
System:
The UNT Digital Library
ITER disruption modeling using TSC (Tokamak Simulation Code)
Design of the ITER vacuum vessel (VV) is driven strongly by disruption-induced forces. We use the Tokamak Simulation Code (TSC) to model disruptions for the ITER physics phase (I{sub p} = 22 MA) and predict the time evolution of currents and forces on the VV. For a plasma vertically displaced to Z{sub axis} = {minus}1.0m before disruption and decaying at a rate of < dI{sub p}/dt > {approx equal} {minus}1.0MA/ms, the induced VV current peaks at 18 MA. The maximum radial VV force F{sub R} is 56 MN/rad; the maximum vertical force F{sub Z} is 5.4 MN/rad; and the maximum VV disruption pressure is 1.0 MPa. Variations in VV resistance (20 - 160 {mu}{Omega}) and < dI{sub p}/dt > (1 - 2.5 MA/ms) do not change F{sub R} significantly. The dependence of the forces on the initial plasma displacement and < dI{sub p}/dt > behavior, and the responses of other conducting structures are discussed. 2 refs., 6 figs.
Date:
November 13, 1989
Creator:
Sayer, R. O.; Peng, Y. K. M.; Wesley, J. C.; Jardin, S. C. (Oak Ridge National Lab., TN (USA); General Atomics, San Diego, CA (USA) & Princeton Univ., NJ (USA). Plasma Physics Lab.)
Object Type:
Article
System:
The UNT Digital Library
The theory of hybrid stochastic algorithms
These lectures introduce the family of Hybrid Stochastic Algorithms for performing Monte Carlo calculations in Quantum Field Theory. After explaining the basic concepts of Monte Carlo integration we discuss the properties of Markov processes and one particularly useful example of them: the Metropolis algorithm. Building upon this framework we consider the Hybrid and Langevin algorithms from the viewpoint that they are approximate versions of the Hybrid Monte Carlo method; and thus we are led to consider Molecular Dynamics using the Leapfrog algorithm. The lectures conclude by reviewing recent progress in these areas, explaining higher-order integration schemes, the asymptotic large-volume behaviour of the various algorithms, and some simple exact results obtained by applying them to free field theory. It is attempted throughout to give simple yet correct proofs of the various results encountered. 38 refs.
Date:
November 21, 1989
Creator:
Kennedy, A.D. (Florida State Univ., Tallahassee, FL (USA). Supercomputer Computations Research Inst.)
Object Type:
Article
System:
The UNT Digital Library