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Development of a high-density energy-storage capacitor for Nova (open access)

Development of a high-density energy-storage capacitor for Nova

This paper covers Maxwell's approach to developing energy storage capacitors. Based on previous capacitor designs of 3 KJ, 5 KJ and 10 KJ, the final Nova 12.5 KJ capacitor evolved. At the outset of the Nova capacitor development program, a relatively new dielectric system, polypropylene-paper-DOP, seemed to show superiority in volumetric efficiency, life, and more importantly cost. However, as a result of studies performed at Maxwell, a high-density, energy-storage capacitor was developed utilizing new high-quality, high-density paper and caster oil as the dielectric. Test data have demonstrated that the Maxwell 12.5 KJ capacitor exceeds all LLNL's qualification requirements.
Date: October 22, 1981
Creator: Haskell, D. K.; Cooper, R. A.; Sevigny, J. A.; Merritt, B. T.; Carder, B. M. & Whitham, K.
System: The UNT Digital Library
Characterizing the nano and micro structure of concrete to improve its durability (open access)

Characterizing the nano and micro structure of concrete to improve its durability

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images on ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools will be shown on this paper.
Date: October 22, 2008
Creator: Monteiro, P. J. M.; Kirchheim, A. P.; Chae, S.; Fischer, P.; MacDowell, A. A.; Schaible, E. et al.
System: The UNT Digital Library
Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory (open access)

Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory

I present three recent results from searches for exotic physics at the BABAR/PEP-II B-factory. These results span many of the samples produced at the B-factory, including B mesons, {tau} leptons, and {Upsilon}(3S) mesons. We have searched for CPT-violation in B{sup 0} mixing and find no significant deviation from the no-violation hypothesis. We have also searched for lepton-flavor-violating decays of the {tau} using {tau}{sup -} {yields} {omega}{ell}{sup -} and {tau}{sup -} {yields} {ell}{sup -}{ell}{sup +}{ell}{sup -} and their charge conjugates. We find no evidence for these processes and set upper limits on their branching fractions. Finally, we have searched for a low-mass Higgs boson in the decay {Upsilon}(3S) {yields} {gamma}A{sup 0}, where the Higgs decays invisibly. We find no evidence for such a decay and set upper limits across a range of possible Higgs masses.
Date: October 22, 2008
Creator: Sekula, Stephen Jacob
System: The UNT Digital Library
The National Ignition Facility: The world's largest optical system (open access)

The National Ignition Facility: The world's largest optical system

None
Date: October 22, 2007
Creator: Stolz, C J
System: The UNT Digital Library
Potential of Photovoltaics (open access)

Potential of Photovoltaics

Presented at the Association of Industrial Metallizers, Coaters and Laminators (AIMCAL) Fall Technical Conference 2008 and 22nd International Vacuum Web Coating Conference held October 19-22, 2008 in Myrtle Beach, South Carolina. This presentation discusses PV in the world energy portfolio, PV basics, PV technologies, and vacuum web-coating applications in PV.
Date: October 22, 2008
Creator: Nelson, B. P.
System: The UNT Digital Library
On The Reproducibility of Seasonal Land-surface Climate (open access)

On The Reproducibility of Seasonal Land-surface Climate

The sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the ''reproducibility'' of continental climate for different initial conditions, spatio-temporal correlations are computed across paired realizations of eleven model land-surface variables in which the seasonal cycle is either included or excluded--the former case being pertinent to climate simulation, and the latter to seasonal anomaly prediction. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is substantially higher in the Tropics; its spatial reproducibility also markedly fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation. However, the overall degree of reproducibility depends strongly on the particular land-surface anomaly considered. It is also shown that the predictability of a land-surface anomaly implied by its reproducibility statistics is consistent with what is inferred from more conventional predictability …
Date: October 22, 2004
Creator: Phillips, T J
System: The UNT Digital Library
U.S. and Russian Collaboration in the Area of Nuclear Forensics (open access)

U.S. and Russian Collaboration in the Area of Nuclear Forensics

Nuclear forensics has become increasingly important in the fight against illicit trafficking in nuclear and other radioactive materials. The illicit trafficking of nuclear materials is, of course, an international problem; nuclear materials may be mined and milled in one country, manufactured in a second country, diverted at a third location, and detected at a fourth. There have been a number of articles in public policy journals in the past year that call for greater interaction between the U. S. and the rest of the world on the topic of nuclear forensics. Some believe that such international cooperation would help provide a more certain capability to identify the source of the nuclear material used in a terrorist event. An improved international nuclear forensics capability would also be important as part of the IAEA verification toolkit, particularly linked to increased access provided by the additional protocol. A recent study has found that, although international progress has been made in securing weapons-usable HEU and Pu, the effort is still insufficient. They found that nuclear material, located in 40 countries, could be obtained by terrorists and criminals and used for a crude nuclear weapon. Through 2006, the IAEA Illicit Trafficking Database had recorded a …
Date: October 22, 2007
Creator: Kristo, M J
System: The UNT Digital Library
Diffusion of a Highly-Charged Supramolecular Assembly: Direct Observation of Ion-Association in Water (open access)

Diffusion of a Highly-Charged Supramolecular Assembly: Direct Observation of Ion-Association in Water

Understanding the solution behavior of supramolecular assemblies is essential for a full understanding of the formation and chemistry of synthetic host-guest systems. While the interaction between host and guest molecules is generally the focus of mechanistic studies of host-guest complexes, the interaction of the host-guest complex with other species in solution remains largely unknown, although in principle accessible by diffusion studies. Several NMR techniques are available to monitor diffusion and have recently been reviewed. Pulsed gradient spin-echo (PGSE) NMR methods have attracted increasing interest, since they allow diffusion coefficients to be measured with high accuracy; they have been successfully used with observation of {sup 7}Li and {sup 31}P nuclei as well as with {sup 1}H NMR. We report here the direct measurement of diffusion coefficients to observe ion-association interactions by counter cations with a highly-charged supramolecular assembly. Raymond and coworkers have described the design and chemistry of a class of metal-ligand supramolecular assemblies over the past decade. The [Ga{sub 4}L{sub 6}]{sup 12-} (L = 1,5-bis(2,3-dihydroxybenzamido)naphthalene) (1) (Figure 1) assembly has garnered the most attention, with the exploration of the dynamics and mechanism of guest exchange as well as the ability of 1 to achieve either stoichiometric or catalytic reactions inside …
Date: October 22, 2007
Creator: University of California, Berkeley; Laboratory, Lawrence Berkeley National; Raymond, Kenneth; Pluth, Michael D.; Tiedemann, Bryan E.F.; van Halbeek, Herman et al.
System: The UNT Digital Library
Measured and projected performance of plasma direct converters (open access)

Measured and projected performance of plasma direct converters

Test results from two plasma direct converters and their predicted cost and performance on tandem mirror fusion reactors are present. The tests were done at high power density (approx. 70 W/cm/sup 2/) in steady state to simulate the predicted conditions in a reactor. A single stage unit and a two-stage unit of the Venetian blind type were tested at up to 100 kV and 6 kW for a total time of about 80 hours. Measured efficiencies, when projected to a reactor, are typically about 50% for a single stage unit and 60 to 70% for a two-stage unit, depending on the energy distribution of the ions, the degree of subdivision of the collectors, and on the gas pressure. The high ambipolar potential in tandem mirror devices makes this good efficiency possible. When radiatively cooled grids are used, the incident power density is limited to about 100 W/cm/sup 2/ by the thermionic emission of electrons.
Date: October 22, 1981
Creator: Barr, W.L. & Moir, R.W.
System: The UNT Digital Library
Engineering problems of the fusion breeder (open access)

Engineering problems of the fusion breeder

A study of fission suppressed blankets for the tandem mirror not only showed such blankets to be feasible but also to be safer than fissioning blankets. Such hybrids could produce enough fissile material to support up to 17 light water reactors of the same nuclear power rating. Beryllium was compared to /sup 7/Li for neutron multiplication; both were considered feasible but the blanket with Li produced 20% less fissile fuel per unit of nuclear power in the reactor. The beryllium resource, while possibly being too small for extensive pure fusion application, would be adequate (with carefully planned industrial expansion) for the hybrid because of the large support ratio, and hence few hybrids required. Radiation damage and coatings for beryllium remain issues to be resolved by further study and experimentation. Molten salt reprocessing was compared to aqueous solution reprocessing (thorex). The molten salt reprocessing cost is $3.4/g fissile, whereas aqueous reprocessing cost $24 or $43/g for the thorium metal or oxide fuel form.
Date: October 22, 1981
Creator: Moir, R. W.; Lee, J. D. & Barr, W. L.
System: The UNT Digital Library
MFTF-B electron-cyclotron-resonance heating system (open access)

MFTF-B electron-cyclotron-resonance heating system

The MFTF-B ECRH system will provide 1.6-MW of microwave power for heating of electrons within the thermal barrier and potential maximum regions of the plasma end-plugs. Absorption of this radiation increases the resonant electron energy which locally alters the electrostatic confining potential within the plasma. The result is a thermal barrier which will isolate end-plug electrons from those in the solenoid thus increasing the plasma confinement time. Microwave energy will be generated by eight 200 kW gyrotrons located outside the vacuum vessel at strategic positions near each end-plug. High voltage dc power will be obtained from a -90 kV, 90 A power supply. A compensation network will condition the dc power and channel it to eight independent pulse power regulatory/isolation networks. Each of these networks will, on command, provide -80 kV, 8 A of dc power to its attendant gyrotron cabinet positioned within the vault. Each gyrotron will interface to a quasi-optical waveguide which will transport microwave power to an antenna system located inside the vacuum vessel. The antenna systems will direct the microwave radiation into the resonant heating zones of the plasma. A local control and monitoring system will interface to the MFTF-B Supervisory Control and Diagnostics System. This …
Date: October 22, 1981
Creator: Krause, K. H.; Pollock, G. G. & Yugo, J. J.
System: The UNT Digital Library
Engineering problems of tandem-mirror reactors (open access)

Engineering problems of tandem-mirror reactors

We have completed a comparative evaluation of several end plug configurations for tandem mirror fusion reactors with thermal barriers. The axi-cell configuration has been selected for further study and will be the basis for a detailed conceptual design study to be carried out over the next two years. The axi-cell end plug has a simple mirror cell produced by two circular coils followed by a transition coil and a yin-yang pair, which provides for MHD stability. This paper discusses some of the many engineering problems facing the designer. We estimated the direct cost to be 2$/W/sub e/. Assuming total (direct and indirect) costs to be twice this number, we need to reduce total costs by factors between 1.7 and 2.3 to compete with future LWRs levelized cost of electricity. These reductions may be possible by designing magnets producing over 20T made possible by use of combinations of superconducting and normal conducting coils as well as improvements in performance and cost of neutral beam and microwave power systems. Scientific and technological understanding and innovation are needed in the area of thermal barrier pumping - a process by which unwanted particles are removed (pumped) from certain regions of velocity and real space …
Date: October 22, 1981
Creator: Moir, R.W.; Barr, W.L. & Boghosian, B.M.
System: The UNT Digital Library
Multidisciplinary training program to create new breed of radiation monitor: the health and safety technician (open access)

Multidisciplinary training program to create new breed of radiation monitor: the health and safety technician

A multidiscipline training program established to create a new monitor, theHealth and Safety Technician, is described. The training program includes instruction in fire safety, explosives safety, industrial hygiene, industrial safety, health physics, and general safety practices.
Date: October 22, 1979
Creator: Vance, W.F.
System: The UNT Digital Library
Production and loss of H/sup -/ and D/sup -/ in the volume of a plasma (open access)

Production and loss of H/sup -/ and D/sup -/ in the volume of a plasma

The study of the production and loss of negative ions, H/sup -/ and D/sup -/, in the volume of a plasma has received considerable attention since the measurement of anomalously high densities of H/sup -/ in 1977. The most probable mechanism for production is dissociative attachment (DA) to vibrationally highly-excited hydrogen molecules. New diagnostics developed for this purpose are photodetachment and the extension of coherent anti-Stokes Raman scattering (CARS) systems to the sensitivity required for low-pressure gases. Measurements and calculations indicate that the important loss mechanisms are diffusion to the walls at low densities and collisional destruction of several types at plasma densities above 10/sup 10/ cm/sup -3/. Production mechanisms must be highly efficient to compete with the losses. It appears to be straightforward to extrapolate measurements and theory to the densities above 10/sup 12/ cm/sup -3/ that are required for an intense source of D/sup -/ for neutral beam injection into magnetically-confined fusion devices.
Date: October 22, 1981
Creator: Hamilton, G.W. & Bacal, M.
System: The UNT Digital Library
Overview of tritium processing development at the tritium systems test assembly (open access)

Overview of tritium processing development at the tritium systems test assembly

The Tritium Systems Test Assembly (TSTA) at the Los Alamos National Laboratory has been operating with tritium since June 1984. Presently there are some 50 g of tritium in the main processing loop. This 50 g has been sufficient to do a number of experiments involving the cryogenic distillation isotope separation system and to integrate the fuel cleanup system into the main fuel processing loop. In January 1986 two major experiments were conducted. During these experiments the fuel cleanup system was integrated, through the transfer pumping system, with the isotope separation system, thus permitting testing on the integrated fuel processing loop. This integration of these systems leaves only the main vacuum system to be integrated into the TSTA fuel processing loop. In September 1986 another major tritium experiment was performed in which the integrated loop was operated, the tritium inventory increased to 50 g and additional measurements on the performance of the distillation system were taken. In the period June 1984 through September 1986 the TSTA system has processed well over 10/sup 8/ Ci of tritium. Total tritium emissions to the environment over this period have been less than 15 Ci. Personnel exposures during this period have totaled less than …
Date: October 22, 1986
Creator: Anderson, J. L.
System: The UNT Digital Library
Primary water stress corrosion cracking of Alloy 600: Effects of processing parameters (open access)

Primary water stress corrosion cracking of Alloy 600: Effects of processing parameters

Correlations of stress corrosion cracking (SCC) data in deaerated water with temperature, stress, metallography, and processing for laboratory test specimens are presented. Initiation time data show that a low temperature anneal and resulting absence of grain boundary carbides result in a material having increased susceptibility to SCC. Data also show that hot worked and annealed Alloy 600 is more resistant than cold worked and annealed material, both having carbide decorated grain boundaries. In absence of grain boundary carbides, both materials are equally susceptible. Low temperature thermal treatment (1100F) reduces SCC susceptibility with or without grain boundary decoration. Weld metal data and data correlations developed from 700 double U-bends are presented. Data demonstrate the effect of increased carbon content to improve SCC resistance. The data shows that the general relation of time, temperature and strain for wrought material is followed for the weld metal. The weld process used did not affect the SCC susceptibility of EN-82 which showed a greater resistance to SCC than EN-62. Stress relief of weld deposits showed an improvement for wrought material. Heat affected zone resistance was improved if the starting material received a high temperature anneal (1850 to 2000F). Range of SCC initiation times for weld …
Date: October 22, 1993
Creator: Seman, D. J.; Webb, G. L. & Parrington, R. J.
System: The UNT Digital Library
Facilities for Development of Modified Nitride-Based Fuel Pellets (open access)

Facilities for Development of Modified Nitride-Based Fuel Pellets

Facilities to support development of modified nitride-based reactor fuel pellets have been activated and are now in operation at Lawrence Livermore National Laboratory. These facilities provide the controls and monitored laboratory conditions required to produce, evaluate, and verify quality of the nitride-based product required for this fuel application. By preserving the high melting point, high thermal conductivity, and high actinide density properties of nitride fuel while enhancing stoichiometry, density, and grain structure, and by applying inert matrix (ZrN) and neutron absorbing (HfN) additives for improved stability and burn-up characteristics, the requirements for a long-life fuel to support sealed core reactor applications may be met. This paper discusses requirements for producing the modified nitride powders for sintering of fuel pellets, translation of these requirements into facility specifications, and implementation of these specifications as facility capabilities.
Date: October 22, 2003
Creator: Meier, T.; Ebbinghaus, B. & Choi, J.
System: The UNT Digital Library
Evaluation of the Relative Importance of Parameters Influencing Perforation Cleanup (open access)

Evaluation of the Relative Importance of Parameters Influencing Perforation Cleanup

Completion of cased and cemented wells by shaped-charge perforation results in damage to the formation, which can significantly reduce well productivity. Typically, underbalanced conditions are imposed during perforation in an effort to remove damaged rock and shaped-charge debris from the perforation tunnel. Immediately after the shaped-charge jet penetrates the formation, there is a transient surge of fluid from the formation through the perforation and into the well bore. Experimental evidence suggests that it is this transient pressure surge that leads to the removal of damaged rock and charge debris leaving an open perforation tunnel. We have developed a two-stage computational model to simulate the perforation process and subsequent pressure surge and debris removal. The first stage of the model couples a hydrocode with a model of stress-induced permeability evolution to calculate damage to the formation and the resulting permeability field. The second stage simulates the non-Darcy, transient fluid flow from the formation and removes damaged rock and charge debris from the perforation tunnel. We compare the model to a series of API RP43 section 4 flow tests and explore the influence of fluid viscosity and rock strength on the final perforation geometry and permeability.
Date: October 22, 2003
Creator: Detwiler, R L; Morris, J P; Karacan, C O; Halleck, P M & Hardesty, J
System: The UNT Digital Library
Density-functional calculations of a, b, g, d, dp, and e plutonium (open access)

Density-functional calculations of a, b, g, d, dp, and e plutonium

Total energies for the six known polymorphs of plutonium metal have been calculated within spin and orbital polarized density-functional theory as a function of lattice constant. Theoretical equilibrium volumes and bulk moduli correspond well with experimental data and the calculated total energies are consistent with the known phase diagram of Pu. It is shown that a preference for formation of magnetic moments, increasing through the {alpha} {yields} {beta} {yields} {gamma} phases, explain their position in the ambient pressure phase diagram and their anomalous variation of atomic density. A simple model is presented that establishes a relationship between atomic density, crystal symmetry, and magnetic moments which is universally valid for all Pu phases.
Date: October 22, 2003
Creator: Soderlind, P & Sadigh, B
System: The UNT Digital Library
Photodetectors for Scintillator Proportionality Measurement (open access)

Photodetectors for Scintillator Proportionality Measurement

None
Date: October 22, 2010
Creator: Moses, William W.; Choong, W. -S.; Hull, G.; Payne, S.; Cherepy, N. & Valentine, J. D.
System: The UNT Digital Library
Integrated process modeling for the laser inertial fusion Energy (LIFE) generation system (open access)

Integrated process modeling for the laser inertial fusion Energy (LIFE) generation system

A concept for a new fusion-fission hybrid technology is being developed at Lawrence Livermore National Laboratory. The primary application of this technology is base-load electrical power generation. However, variants of the baseline technology can be used to 'burn' spent nuclear fuel from light water reactors or to perform selective transmutation of problematic fission products. The use of a fusion driver allows very high burn-up of the fission fuel, limited only by the radiation resistance of the fuel form and system structures. As a part of this process, integrated process models have been developed to aid in concept definition. Several models have been developed. A cost scaling model allows quick assessment of design changes or technology improvements on cost of electricity. System design models are being used to better understand system interactions and to do design trade-off and optimization studies. Here we describe the different systems models and present systems analysis results. Different market entry strategies are discussed along with potential benefits to US energy security and nuclear waste disposal. Advanced technology options are evaluated and potential benefits from additional R&D targeted at the different options is quantified.
Date: October 22, 2009
Creator: Meier, W. R.; Anklam, T. M.; Erlandson, A. C.; Miles, R. R.; Simon, A. J.; Sawicki, R. et al.
System: The UNT Digital Library
Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping (open access)

Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping

Magnetic (Ga{sub x}Fe{sub 1-x}){sub 3}O{sub 4} nanoparticles with 5%-33% gallium doping (x = 0.05-0.33) were measured using x-ray absorption spectroscopy and x-ray magnetic circular dichroism to determine that the Ga dopant is substituting for Fe{sub 3+} as Ga{sub 3+} in the tetrahedral A-site of the spinel structure, resulting in an overall increase in the total moment of the material. Frequency-dependent alternating-current magnetic susceptibility measurements showed these particles to be weakly interacting with a reduction of the cubic anisotropy energy term with Ga concentration. The element-specific dichroism spectra show that the average Fe moment is observed to increase with Ga concentration, a result consistent with the replacement of A-site Fe by Ga.
Date: October 22, 2010
Creator: Pool, V. L.; Klem, M. T.; Chorney, C. L.; Arenholz, E. & Idzerda, Y.U.
System: The UNT Digital Library
Symmetry and illumination uniformity requirements for high density laser-driven implosions (open access)

Symmetry and illumination uniformity requirements for high density laser-driven implosions

As laser capabilities increase, implosions will be performed to achieve high densities. Criteria are discussed for formation of a low-density corona, preheated supersonically, which increases the tolerance of high convergence implosions to non-uniform illumination by utilizing thermal smoothing. We compare optimized double shell target designs without and with atmosphere production. Two significant penalties are incurred with atmosphere production using 1 ..mu..m laser light. First, a large initial shock at the ablation surface limits the pulse shaping flexibility, and degrades implosion performance. Second, the mass and heat capacity of the atmosphere reduce the energy delivered to the ablation surface and the driving pressures obtained for a given input energy. Improvement is possible using 2 ..mu..m light for the initial phase of the implosion. We present results of 2-D simulations which evaluate combined symmetry and stability requirements. At l = 8, the improvement produced in the example is a factor of 10, giving tolerance of 10 percent.
Date: October 22, 1976
Creator: Mead, W. C. & Lindl, J. D.
System: The UNT Digital Library
Computer simulation of recent laser driven implosions of glass microshells (open access)

Computer simulation of recent laser driven implosions of glass microshells

Recent experiments at the LLL 2.0 terawatt laser irradiation facility Argus have been conducted on glass microshells filled with equimolar DT gas. A variety of microshell dimensions and laser pulse widths have been used with the best results producing in excess of 10/sup 8/ fusion reactions. Numerical simulation of selected experiments using the LASNEX computer code confirm the measured performance. Peak DT ion temperatures of about 5 keV and densities of .2 gm/cm/sup 3/ are calculated and are in agreement with that from neutron time-of-flight and alpha particle spectral measurements together with x-ray diagnostics. Laser light absorption is about 20% efficient. General characteristics of ''exploding pusher'' targets will be discussed.
Date: October 22, 1976
Creator: Thiessen, A. R. & Larsen, J. T.
System: The UNT Digital Library