40 Matching Results

Results open in a new window/tab.

Enhanced filtration program at LLL. A progress report. (open access)

Enhanced filtration program at LLL. A progress report.

As part of Lawrence Livermore Laboratory's Enhanced Filtration Program, we are investigating the use of an externally applied electric field to improve the performance of fibrous filters. Our objective in this program is to develop filtration systems for the nuclear industry that will reduce the cost and volume of nuclear waste associated with present systems. We have developed a new theory of the electrostatic filter that is consistent with experimental tests made during transient and steady-state conditions. For these tests, we used ac and dc electric fields, insulated and noninsulated electrodes, and conducting and nonconducting filter media; all tests were conducted in our small-scale 25 l/s test system, using sodium chloride aerosols. Our theory employs a new mechanism based on the attraction between charged particles and charged fibers in addition to the previously proposed mechanism based on the attraction between charged particles and polarized fibers. In this theory, fibers are charged when charged particles deposit on them. We have also developed a theoretical model that explains the increase in filter efficiency and pressure drop when particles load on the filter. The filter loading tests we conducted to evaluate this model verify its accuracy to a remarkable degree. By using the …
Date: July 28, 1978
Creator: Bergman, W.; Taylor, R. D.; Miller, H. H.; Bierman, A. H.; Hebard, H. D.; daRoza, R. A. et al.
System: The UNT Digital Library
Development of an actively modelocked and Q-switched oscillator for laser fusion program at LLL (open access)

Development of an actively modelocked and Q-switched oscillator for laser fusion program at LLL

A method was developed that allows the mode-locking process to go to its steady state condition before the laser is Q-switched. This is done by pumping the laser quasi-cw for about 5 ms. During this time, the loss in the Q-switch is such that the laser will just slightly go above threshold. The active modulator is on during this time, and the laser oscillates quasi-cw for a period long enough to obtain stable transform-limited short pulses. At the end of this prelase period, the laser is Q-switched, and a train of stable, short pulses is obtained.
Date: July 19, 1978
Creator: Kuizenga, D.J.
System: The UNT Digital Library
Measuring social risk and determining its acceptability (open access)

Measuring social risk and determining its acceptability

The implementation of a nuclear waste management technology raises several issues concerning the regulation of social risk. This paper presents a decision analytic approach to resolving some of those issues. A methodology for developing a radiological risk measure is presented, and several approaches to defining acceptable levels of that risk measure are considered. The methodology presented is oriented toward the development of radiological performance objectives for use as guidance in the drafting of regulations.
Date: July 14, 1978
Creator: Lathrop, J.W.
System: The UNT Digital Library
In-duct countermeasures for reducing fire-generated-smoke-aerosol exposure to HEPA filters. [High efficiency particulate aerosol] (open access)

In-duct countermeasures for reducing fire-generated-smoke-aerosol exposure to HEPA filters. [High efficiency particulate aerosol]

An experimental program was conducted to assess the endurance and lifetime of HEPA filters exposed to fire-generated aerosols, and to reduce the aerosol exposure by installing engineering countermeasures in the duct between the fire source and HEPA filters. Large cribs of wood and other potential fuels of interest were ''forcefully burned'' in a partially ventilated enclosure. In a ''forceful burn'' the crib of fuel is continuously exposed to an energetic premixed methane flame during the entire experimental period. This tactic serves two purposes: it optimizes the production of smoke rich in unburned pyrolyzates which provides severe exposure to the filters, and it facilitates the ignition and enhances the combustion of cribs formed with synthetic polymers. The experiments were conducted in an enclosure specifically designed and instrumented for fire tests. The test cell has a volume of 100 m/sup 3/ and includes instrumentation to measure the internal temperature distribution, pressure, thermal radiation field, flow fields, gas concentration, particulate size distribution and mass, fuel weight loss, inlet and exit air velocities, and smoke optical density. The countermeasure techniques include the use of passively operated sprinkler systems in the fire test cell, of fine and dense water scrubbing sprays, and of rolling prefiltration …
Date: July 12, 1978
Creator: Alvares, N. J.; Beason, D. G. & Ford, H. W.
System: The UNT Digital Library
Estimates of time-dependence fatigue behavior of type 316 stainless steel subject to irradiation damage in fast breeder and fusion power reactor systems. [Fluence 1--2. 63 x 10/sup 26/ n/m/sup 2/ (E > 0. 1 MeV/ at 593/sup 0/C] (open access)

Estimates of time-dependence fatigue behavior of type 316 stainless steel subject to irradiation damage in fast breeder and fusion power reactor systems. [Fluence 1--2. 63 x 10/sup 26/ n/m/sup 2/ (E > 0. 1 MeV/ at 593/sup 0/C]

Cyclic lives obtained from strain controlled fatigue tests at 593/sup 0/C from specimens irradiated to a fluence of 1 to 2.63 x 10/sup 26/ n/m/sup 2/ (E greater than 0.1 MeV) were compared to predictions based on the method of strainrange partitioning. When appropriate tensile and creep-rupture ductilities were employed reasonably good estimates of the influence of hold periods and irradiation damage on the fully reversed fatigue life of type 316 stainless steel could be made. Ductility values for 20 percent cold-worked type 316 stainless steel specimens irradiated in a mixed spectrum fission reactor were used to estimate fusion reactor first wall lifetime. The ductility values were from irradiations that simulate the environment of the first wall of a fusion reactor. Neutron wall loadings ranging from 2 to 5 MW/m/sup 2/ were used. Results, although conjectural because of the many assumptions, tended to show that 20 percent cold-worked type 316 stainless steel could be used as a first wall material meeting a 7.5 to 8.5 MW-year/m/sup 2/ lifetime goal provided the neutron wall loading does not exceed more than about 2 MW/m/sup 2/. Results were obtained for an air environment, and it is expected that the actual vacuum environment will …
Date: July 10, 1978
Creator: Brinkman, C.R.; Liu, K.C. & Grossbeck, M.L.
System: The UNT Digital Library
Field reversal in mirror machines (open access)

Field reversal in mirror machines

This report discusses some of the physics issues anticipated in field-reversed mirrors. The effect of current cancellation due to electrons is described. An estimate is made of the required impurity level to maintain a field-reversed configuration. The SUPERLAYER code is used to simulate the high-..beta.. 2XIIB results, and favorable comparisons require inclusion of quasilinear RF turbulence. Impact of a quadrupole field on field-line closure and resonant transport is discussed. A simple self-consistent model of ion currents is presented. Conditions for stability of field-reversed configurations to E x B driven rotations are determined.
Date: July 10, 1978
Creator: Pearlstein, L. D.; Anderson, D. V. & Boozer, A. H.
System: The UNT Digital Library
Reduction of irradiation-induced creep by point defect trapping (open access)

Reduction of irradiation-induced creep by point defect trapping

The theory of point defect trapping was applied to predict the effect of solutes on the steady-state dislocation climb creep rate. Vacancy loops generated in the cascades of point defect production by heavy particles were included. It is shown that the effect of vacancy loops on the creep rate is mathematically equivalent to a simultaneous reduction in the vacancy trapping rate at solutes as well as in the free point defect generation rate and recombination coefficient. These parameters are reduced by the ratio of the sink strength without vacancy loops to the total sink strength. Solute trapping and vacancy loops do not reduce the unperturbed creep rates by more than an order of magnitude for the parametric range considered.
Date: July 10, 1978
Creator: Mansur, L. K. & Wolfer, W. G.
System: The UNT Digital Library
Studies of tandem mirror confinement (open access)

Studies of tandem mirror confinement

This paper describes a number of physics studies relevant to tandem mirror confinement. We give the basic axial confinement laws and show that T/sub e/ depends critically upon end loss. Sufficient central-cell end loss can stabilize the drift-cyclotron loss-cone mode in the plugs, although the resultant T/sub e/ scaling is too slow for reactors. Minimum-B plugs stabilize flute MHD- and rotation-driven modes; local ballooning sets limits on ..beta.. > or equal to 0.5. Proper magnetic symmetry is important for good drift confinement. For small increases in the total injected power, supplementary ion-cyclotron r.f. heating can halve the neutral-beam energy required to maintain plug densities.
Date: July 10, 1978
Creator: Baldwin, D. E.; Cohen, R. H.; Foote, J. H.; Hall, L. S.; Kaiser, T. B.; Logan, B. G. et al.
System: The UNT Digital Library
Time-dependent FEM solution of the incompressible Navier--Stokes equations in two- and three-dimensions (open access)

Time-dependent FEM solution of the incompressible Navier--Stokes equations in two- and three-dimensions

Future prospects regarding the numerical solution of the Navier-Stokes equations using the finite element method are discussed. Since the ultimate goal is to solve these equations in three-dimensions, only the primitive variable (u,P) formulation is considered. A novel feature of the two-dimensional solution technique relates to the methodology developed and employed for solving the semi-discretized system of ordinary differential equations, which are outlined in the section describing the development of the two-dimensional code. Following the discussion of numerical results from two-dimensional calculations, three-dimensional flows are discussed, where several potentially viable options are considered. (TFD)
Date: July 7, 1978
Creator: Gresho, P.M.; Lee, R.L.; Sani, R.L. & Stullich, T.W.
System: The UNT Digital Library
Apparatus for the field evaluation of geothermal effluent injection (open access)

Apparatus for the field evaluation of geothermal effluent injection

Methods for evaluating subsurface disposal systems, based on data derived from membrane filtration tests and core flooding experiments, have been described in the literature. These techniques were used to develop and successfully test equipment for evaluation of injectability of any geothermal effluent including hypersaline brine from the Salton Sea Geothermal Field. A schematic diagram of the prototype system for filtration and core flooding is included.
Date: July 1, 1978
Creator: Netherton, R. & Owen, L.B.
System: The UNT Digital Library
Central collisions of relativistic nuclei. [Cross sections, partial data analysis, yield 250 MeV/nucleon to 2. 1 GeV/nucleon] (open access)

Central collisions of relativistic nuclei. [Cross sections, partial data analysis, yield 250 MeV/nucleon to 2. 1 GeV/nucleon]

New data for relativistic heavy ion collisions are presented for the emitted protons and pions, and for the average multiplicities and angular correlations of the charged particles. Comparisons with several different theoretical approaches are made including the nuclear firestreak model. It appears that there is a group of nucleons with randomized motion and high temperature. The stage is reached where one is beginning to look for effects due to the expansion of a compressed region. 16 references.
Date: July 1, 1978
Creator: Poskanzer, A.M.
System: The UNT Digital Library
THE COVALENT BINDING OF ENANTIOMERIC BENZO [A] PYRENE DIOL EPOXIDES TO DOUBLE STRANDED DNA IS STEREOSELECTIVE (open access)

THE COVALENT BINDING OF ENANTIOMERIC BENZO [A] PYRENE DIOL EPOXIDES TO DOUBLE STRANDED DNA IS STEREOSELECTIVE

Reaction of optically pure (+) and (-) 7{beta},8{alpha}-dihydroxy-9{alpha},10{alpha}-epoxy-7,8,9.10-tetrahydrobenzo[a]pyrene with DNA in vitro yielded diastereomeric covalent adducts with the exocyclic amino groups of deoxyguanosine and deoxyadenosine. The ratio of two deoxyguanosine diastereomers derived by reacting the (+) and (-) hydrocarbons with native calf thymus and double stranded 0X174 DNA was 20:1 while reaction of the enantiomers with heat denatured calf thymus and single stranded 0X174 DNA resulted in a ratio near 1:1. In contrast, deoxyaadenosine diastereomer pairs were approximately 1:1 in all cases studied. The (+) and (-) enantiomers of the benzo[a]pyrene diol epoxide, therefore, interact asymmetrically with the guanine binding sites of double stranded but not single stranded polydeoxynucleotides. In contrast, reaction of the enantiomers with adenine is not stereoselective.
Date: July 1, 1978
Creator: Meehan, T. & Straub, K.
System: The UNT Digital Library
CUBE (Computer Use By Engineers) symposium abstracts. [LASL, October 4--6, 1978] (open access)

CUBE (Computer Use By Engineers) symposium abstracts. [LASL, October 4--6, 1978]

This report presents the abstracts for the CUBE (Computer Use by Engineers) Symposium, October 4, through 6, 1978. Contributors are from Lawrence Livermore Laboratory, Los Alamos Scientific Laboratory, and Sandia Laboratories.
Date: July 1, 1978
Creator: Ruminer, J.J. (comp.)
System: The UNT Digital Library
Deep-inelastic processes: a workbench for large scale motion in nuclear matter (open access)

Deep-inelastic processes: a workbench for large scale motion in nuclear matter

The most prominent collective modes excited in deep-inelastic reactions are reviewed, and the natural hierarchy provided by their characteristic relaxation times is described. A model is presented which treats the relaxation of the mass asymmetry mode in terms of a diffusion process. Charge distributions and angular distributions as a function of Z calculated with this model are in good agreement with experimental data. An extension of this diffusion model which treats the transfer of energy and angular momentum in terms of particle transfer is described, and is successfully compared with experimental ..gamma..-ray multiplicities as a function of both Q-value and mass asymmetry. The problem of angular momentum transfer is again considered in connection with the sequential fission of heavy, deep-inelastic fragments and the excitation of collective modes in the exit channel is suggested. Lastly, the role of the giant E1 mode in the equilibration of the neutron-to-proton ratio is discussed. 14 figures, 39 references.
Date: July 1, 1978
Creator: Moretto, L. G. & Schmitt, R. P.
System: The UNT Digital Library
Department of Energy's Solar Update. Four Regional Conferences Highlighting the Objectives, Plans, and Experience of the National Commercial Solar Heating and Cooling Demonstration Program and the National Solar Data Program (open access)

Department of Energy's Solar Update. Four Regional Conferences Highlighting the Objectives, Plans, and Experience of the National Commercial Solar Heating and Cooling Demonstration Program and the National Solar Data Program

These proceedings represent the overview and project papers made available to all the participants at each of the regional conferences. Papers not available at time of publication, and additional materials, including a summary and analysis of the Workshop/Panel Sessions are included in the complete proceedings CONF-780701--(Rev.) for which individual abstracts were prepared for each paper. (MHR)
Date: July 1, 1978
Creator: unknown
System: The UNT Digital Library
Energetics of semi-catalyzed-deuterium, light-water-moderated, fusion-fission toroidal reactors (open access)

Energetics of semi-catalyzed-deuterium, light-water-moderated, fusion-fission toroidal reactors

The semi-catalyzed-deuterium Light-Water Hybrid Reactor (LWHR) comprises a lithium-free light-water-moderated blanket with U/sub 3/Si fuel driven by a deuterium-based fusion-neutron source, with complete burn-up of the tritium but almost no burn-up of the helium-3 reaction product. A one-dimensional model for a neutral-beam-driven tokamak plasma is used to determine the operating modes under which the fusion energy multiplication Q/sub p/ can be equal to or greater than 0.5. Thermonuclear, beam-target, and energetic-ion reactions are taken into account. The most feasible operating conditions for Q/sub p/ approximately 0.5 are <n/sub e/>tau/sub E/ = 2 to 4 x 10/sup 14/ cm/sup -3/s, <T/sub e/> = 10 to 20 keV, and E/sub beam/ = 500 to 1000 keV, with approximately 40% of the fusion energy produced by beam-target reactions. Illustrative parameters of LWHRs are compared with those of an ignited D-T reactor.
Date: July 1, 1978
Creator: Jassby, D. L.; Towner, H. H.; Greenspan, E.; Schneider, A.; Misolovin, A. & Gilai, D.
System: The UNT Digital Library
Experimental test of exchange degeneracy in hypercharge exchange reactions at 7 and 11. 5 GeV/c. [Cross sections] (open access)

Experimental test of exchange degeneracy in hypercharge exchange reactions at 7 and 11. 5 GeV/c. [Cross sections]

The two pairs of line-reversed reactions: ..pi../sup +/p ..-->.. K/sup +/..sigma../sup +/; K/sup -/p ..-->.. ..pi../sup -/..sigma../sup +/ and ..pi../sup +/p ..-->.. K/sup +/Y*(1385); K/sup -/p ..-->.. ..pi../sup -/Y*(1385) at two energies: 7 and 11.5 GeV/c were studied. The experiment was conducted in the SLAC 1 m rapid cycling bubble chamber triggered by electronic detectors and an online algorithm. The cross section excess for the K/sup -/ reactions which has shown exchange degeneracy violations at lower energy is still significant but smaller at 7 GeV/c. At 11.5 GeV/c it is found that both the helicity-flip and non-flip dominated processes are consistent with exchange degeneracy predictions. Polarization measurements of the ..sigma../sup +/ and Y* at both energies support dominance in the production process of exchange degenerate K*(890) vector and K*(1490) tensor trajectories. 9 references
Date: July 1, 1978
Creator: Baker, P. A.; Chima, J. S. & Dornan, P. J.
System: The UNT Digital Library
Floating dry cooling: a competitive alternative to evaporative cooling in a binary cycle geothermal power plant (open access)

Floating dry cooling: a competitive alternative to evaporative cooling in a binary cycle geothermal power plant

The application of the floating cooling concept to non-evaporative and evaporative atmospheric heat rejection systems was studied as a method of improving the performance of geothermal powerplants operating upon medium temperature hydrothermal resources. The LBL thermodynamic process computer code GEOTHM is used in the case study of a 50 MWe isobutane binary cycle power plant at Heber, California. It is shown that operating a fixed capacity plant in the floating cooling mode can generate significantly more electrical energy at a higher thermodynamic efficiency and reduced but bar cost for approximately the same capital investment. Floating cooling is shown to benefit a plant which is dry cooled to an even greater extent than the same plant operating with an evaporative heat rejection system. Results of the Heber case study indicate that a dry floating cooling geothermal binary cycle plant can produce energy at a bus bar cost which is competitive with the cost of energy associated with evaporatively cooled systems.
Date: July 1, 1978
Creator: Pines, H.S.; Green, M.A.; Pope, W.L. & Doyle, P.A.
System: The UNT Digital Library
General relativistic gravitation as the theory of broken symmetry of intransitive groups of transformations (open access)

General relativistic gravitation as the theory of broken symmetry of intransitive groups of transformations

General relativistic gravitational theories are constructed from suitable intransitive continuous groups of transformations. A minimal invariant variety forms the unperturbed universe. The formalism of the group is generalized to have the symmetry of its action on this manifold broken by gauge potentials. The theory is expressed in these potentials, and it is shown how the present symmetry breaking is related to a general metric. The physical interpretation of the formalism is outlined. 14 references.
Date: July 1, 1978
Creator: Halpern, L.
System: The UNT Digital Library
High-temperature electronics workshop: progress in the development of microelectronics for the 500/sup 0/C environment (open access)

High-temperature electronics workshop: progress in the development of microelectronics for the 500/sup 0/C environment

This workshop proceedings describes the status of the Los Alamos Scientific Laboratory (LASL) and University of Arizona programs in the development of high-temperature microelectronic devices for geothermal well-logging applications.
Date: July 1, 1978
Creator: McCormick, J.B. (ed.)
System: The UNT Digital Library
Improved x-ray fluorescence capabilities by excitation with high intensity polarized x-rays (open access)

Improved x-ray fluorescence capabilities by excitation with high intensity polarized x-rays

Lowest detection limits are obtained by opening the collimator apertures until the system maximum counting rate is obtained. Selection of polarizer materials is discussed. A cylindrical polarizer is used in a high-intensity polarized x-ray source. (DLC)
Date: July 1978
Creator: Ryon, Richard W. & Zahrt, John D.
System: The UNT Digital Library
Intrusion detection sensors (open access)

Intrusion detection sensors

Intrusion detection sensors are an integral part of most physical security systems. Under the sponsorship of the U.S. Department of Energy, Office of Safeguards and Security, Sandia Laboratories has conducted a survey of available intrusion detection sensors and has tested a number of different sensors. An overview of these sensors is provided. This overview includes (1) the operating principles of each type of sensor, (2) unique sensor characteristics, (3) desired sensor improvements which must be considered in planning an intrusion detection system, and (4) the site characteristics which affect the performance of both exterior and interior sensors. Techniques which have been developed to evaluate various intrusion detection sensors are also discussed.
Date: July 1, 1978
Creator: Williams, J.D.
System: The UNT Digital Library
Management of high-level nuclear wastes (open access)

Management of high-level nuclear wastes

A brief review is given of significant developments in the management of high-level nuclear wastes since the Oct. 1976 first Pacific Basin Conference on Nuclear Power Development and the Fuel Cycle. Emphasis is on policy and technical developments in the U.S., with some attention paid to developments in other countries that have impacted technical direction in the U.S. Spent fuel and its packaging, vitrification, high-level waste glasses, and repositories are discussed. It is concluded that predisposal technology for processing high-level wastes is well developed and that geologic media can be used for disposal of nuclear wastes without significant risk. 19 figures. (DLC)
Date: July 1, 1978
Creator: Platt, A. M. & McElroy, J. L.
System: The UNT Digital Library
Motion of electron-hole drops in Ge (open access)

Motion of electron-hole drops in Ge

Using a new experimental technique based on hysteresis, the time development of the size of a localized packet of electronhole drops (EHD) in a spatially uniform free exciton gas near threshold is measured for times approximately 10/sup 4/ sec. No significant motion is found, determining an upper limit D approximately < 10/sup -9/cm/sup 2/sec/sup -1/ to the possible EHD diffusion constant.
Date: July 1, 1978
Creator: Westervelt, R. M.; Culbertson, J. C. & Black, B. S.
System: The UNT Digital Library