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in publisher: "Lawrence Livermore National Laboratory"

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Radionuclides in plankton from the South Pacific Basin

We have initiated an investigation of the utility of marine plankton as bioconcentrating samplers of low-level marine radioactivity in the southern hemisphere. A literature review has shown that both freshwater and marine plankton have trace element and radionuclide concentration factors (relative to water) of up to 10/sup 4/. We participated in Operations Deepfreeze 1981 and 1982, collecting a total of 48 plankton samples from the USCGC Glacier on its Antarctic cruises. Battelle Pacific Northw… more

Date: March 23, 1984

Creator: Marsh, K.V. & Buddemeier, R.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Stress analysis of MFTF-B getter system bellows. Final report

The MFTF-B design includes a retractable getter system. Eight getter assemblies are planned (4 in each end plug). Electrically heated Ti wires are mounted on a telescoping insertion mechanism and, between machine shots (pulses), are extended into the chamber in the vicinity of inward-facing water-cooled magnet liners. During the shots, the sublimators must be withdrawn because they will intrude into plasma and diagnostic space. Each of the getter assemblies will be mounted on the exterior of th… more

Date: April 1, 1982

Creator: Tokarz, F. J.; Johnson, J. J.; Mukherjee, A. N. & Dalder, E. N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Laser-plasma interaction experiments at laser wavelengths of 1. 064. mu. m, 0. 532. mu. m, and 0. 355. mu. m

The effect of laser wavelength on laser-plasma coupling is one of the critical issues facing the laser driven inertial confinement community. The advantages of using lasers with output wavelength less than 1 ..mu..m, such as enhanced absorption and hydrodynamic efficiency, reduction in parametric instabilities and corresponding suprathermal electron generation, have long been predicted theoretically.

Date: January 1, 1982

Creator: Campbell, E. M.; Mead, W. C. & Turner, R. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Computation of self-consistent 2-D MHD with neutral-beam and bootstrap currents in elongated plasmas

The observation of substantial current drive from neutral beam injection (NBI) in TFTR, JET and DIII-D has led to renewed interest in a steady state, non-inductively driven tokamak. The discovery of apparently considerable neoclassical (bootstrap) current in TFTR, makes a steady state device even more attractive since the bootstrap portion of the current could be obtained without additional power input. Motivated by these results, we have developed a code, ACCOME, which self-consistently comput… more

Date: April 5, 1983

Creator: Devoto, R. S.; Tani, K. & Azumi, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Institutional research and development, FY 1987

The Institutional Research and Development program at Lawrence Livermore National Laboratory fosters exploratory work to advance science and technology, disciplinary research to develop innovative solutions to problems in various scientific fields, and long-term interdisciplinary research in support of defense and energy missions. This annual report describes research funded under this program for FY87. (DWL)

Date: January 1, 1987

Creator: Struble, G. L.; Lawler, G. M.; Crawford, R. B.; Kirvel, R. D.; Peck, T. M.; Prono, J. K. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach

As experiments continue to grow in size and complexity, a few technicians will no longer be able to maintain and operate the complete experiment. Specialization is becoming the norm. Subsystems are becoming very large and complex, requiring a great deal of experience and training for technicians to become qualified maintenance/operation personnel. Formal in-house and off-site programs supplement on-the-job training to fulfill the qualification criteria. This paper presents the Tandem Mirror Exp… more

Date: December 1, 1983

Creator: Mattson, G.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Use of principal components analysis and three-dimensional atmospheric-transport models for reactor-consequence evaluation

This work explores the use of principal components analysis coupled to three-dimensional atmospheric transport and dispersion models for evaluating the environmental consequences of reactor accidents. This permits the inclusion of meteorological data from multiple sites and the effects of topography in the consequence evaluation; features not normally included in such analyses. The technique identifies prevailing regional wind patterns and their frequencies for use in the transport and dispersi… more

Date: January 1, 1982

Creator: Gudiksen, P. H.; Walton, J. J.; Alpert, D. J. & Johnson, J. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fueling of tandem mirror reactors

This paper summarizes the fueling requirements for experimental and demonstration tandem mirror reactors (TMRs), reviews the status of conventional pellet injectors, and identifies some candidate accelerators that may be needed for fueling tandem mirror reactors. Characteristics and limitations of three types of accelerators are described; neutral beam injectors, electromagnetic rail guns, and laser beam drivers. Based on these characteristics and limitations, a computer module was developed fo… more

Date: January 1, 1985

Creator: Gorker, G. E. & Logan, B. G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Use of molybdenum ion source electrodes at RTNS-II

Reports are reported for an ongoing effort to optimize D+ beam production by the MATS-III ion source used at RTNS-II. The three seven-aperture electrodes, originally consisting of water-cooled copper, have now been tested using uncooled molybdenum and with water cooling on the second (decel) electrode only. Details of the change, the results of the testing, and the benefits in operation, performance and cost are given.

Date: September 29, 1986

Creator: Massoletti, D.J.; Harter, G.A. & Heikkinen, D.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Extracted current densities from surface conversion sources of negative ions

The condition for extracting a maximum negative ion current density is found when the product of the radius of the negative ion conversion electrode, the cross-section for negative and positive ion recombination, and the density of positive ions in the ion source equals one. The optimum output is obtained at the highest positive ion density and the smallest electrode radius.

Date: February 10, 1982

Creator: Fink, J.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Cause of pitting in beryllium

Light microscopy, bare-film radiography, secondary ion mass spectroscopy, electron microprobe and physical testing were used to examine beryllium specimens exhibiting a stratified, pitted, pattern after chemical milling. The objective was to find the cause of this pattern. Specimens were found to have voids in excess of density specification allowances. These voids are attributed, at least in part, to the sublimation of beryllium fluoride during the vacuum hot pressing operation. The origin of … more

Date: April 16, 1982

Creator: Kershaw, R. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurements of the dependence of damage thresholds on laser wavelength, pulse duration and film thickness

Results of three experiments will be described. We used 351-nm and 355-nm pulses with durations of 0.6, 1, 5 and 9 ns measure thresholds for a variety of anti-reflectance and high reflectance coatings. The functional form t/sup m/, with t the pulse duration, was used to scale fluence thresholds measured at 0.6 ns to those measured at 9.0 ns. Values of the coefficient m ranged from 0.10 to 0.51. The average value was 0.30. In the second experiment, we measured thresholds at 1064 nm, 527 nm and 3… more

Date: March 1, 1984

Creator: Rainer, F.; Vercimak, C.L.; Milam, D.; Carniglia, C.K. & Tuttle Hart, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials

High-average-power frequency conversion using solid state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (>70%) of Nd:YAG at average powers approaching 100 KW is possible; and for doubling to the blue or ultraviolet regions, the average power may approach 1 MW. Configurations using segmented apertur… more

Date: October 28, 1985

Creator: Eimerl, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Energy Program annual report

The national economy is particularly dependent on efficient electrical generation and transportation. Electrical demand continues to grow and will increasingly rely on coal and nuclear fuels. The nuclear power industry still has not found a solution to the problem of disposing of the waste produced by nuclear reactors. Although coal is in ample supply and the infrastructure is in place for its utilization, environmental problems and improved conversion processes remain technical challenges. In … more

Date: February 1, 1988

Creator: Borg, I.Y. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Adaptive Mesh Refinement for 1-Dimensional Gas Dynamics

We consider the solution of the one-dimensional equation of gas-dynamics. Accurate numerical solutions are difficult to obtain on a given spatial mesh because of the existence of physical regions where components of the exact solution are either discontinuous or have large gradient changes. Numerical methods treat these phenomena in a variety of ways. In this paper, the method of adaptive mesh refinement is used. A thorough description of this method for general hyperbolic systems is given else… more

Date: 1982-08~

Creator: Hedstrom, Gerald; Rodrigue, Garry; Berger, Marsha & Oliger, Joseph

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of energy deposited by charged-particle beams in composite targets

We have measured the energy deposited in two types of composite targets by a number of charged-particle beams: targets made of /sup 238/U, Lucite, and polyethylene were exposed to 0.26-GeV protons and 0.33-GeV deuterons, and aluminum-Lucite composites were exposed to 0.5-GeV electrons. In addition, we measured neutrons and gamma rays emitted from solid targets of various materials (including /sup 238/U and iron) exposed to 0.26-GeV protons and 0.33-GeV deuterons. We used passive detectors (ther… more

Date: July 2, 1980

Creator: Farley, E.; Becker, J.; Crase, K.; Howe, R. & Selway, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Construction and testing of the Mirror Fusion Test Facility magnets

This paper describes the construction and testing of the Mirror Fusion Test Facility superconducting magnet set. Construction of the first Yin Yang magnet was started in 1978. And although this particular magnet was later modified, the final construction of these magnets was not completed until 1985. When completed these 42 magnets weighed over 1200 tonnes and had a maximum stored energy of approximately 1200 MJ at full field. Together with power supplies, controls and liquid nitrogen radiation… more

Date: August 1, 1986

Creator: Kozman, T.; Shimer, D.; VanSant, J. & Zbasnik, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Physics of antimatter-matter reactions for interstellar propulsion

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) … more

Date: August 22, 1986

Creator: Morgan, D.L. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cross Sections for X-Ray Photoelectron-Induced Desorption of Hydrogen Ions From Metal Surfaces

We have measured the cross sections for x-ray photoelectron-induced desorption of hydrogen ions from beryllium, carbon, aluminum, tantalum, and gold surfaces. This report describes the results of the cross-section measurements, and discusses a time-of-flight technique that allows the determination of ionic-desorption cross sections as small as 10/sup -25/ cm/sup 2/ per photoelectron. 19 refs., 7 figs.

Date: September 20, 1985

Creator: Kinney, J. H.; Siekhaus, W. J. & Anderson, R. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Study of impurities in the Tandem Mirror Experiment using extreme-ultraviolet spectroscopy

Impurities in the Tandem Mirror Experiment (TMX) have been studied using extreme ultraviolet spectroscopy. Three time-resolving absolutely-calibrated normal-incidence monochromators, one on each section of TMX, were used to study the impurity emissions in the wavelength range of 300 A to 1600 A. The instruments on the east end cell and central cell were each capable of obtaining spatially-resolved profiles from 22 chords of the plasma simultaneously while the instrument on the west end cell mon… more

Date: May 12, 1982

Creator: Strand, O. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Recent US target-physics-related research in heavy-ion inertial fusion: simulations for tamped targets and for disk experiments in accelerator test facilities

Within the last few years, there have also appeared in the Heavy-Ion Fusion literature several studies of targets which have outer tampers. One-dimensional simulations indicate higher target gains with a judicious amount of tamping. But for these targets, a full investigation has not been carried through in regards to conservative criteria for fluid instabilities as well as reasonable imperfections in target fabrication and illumination symmetry which all affect target ignition and burn. Compar… more

Date: June 24, 1982

Creator: Mark, J.W.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Use of ICRH for startup and initial heating of the TMX-U central cell

Ion cyclotron resonance heating (ICRH) was evaluated and it was found to be satisfactory for use in establishing the conditions necessary to form a thermal barrier in TMX-upgrade (TMX-U). We discuss the constraints that must be satisfied in order to maintain a plasma, and outline a complete startup scenario that ends with the plasma at design parameters. The detailed discussions in this report concentrate on those parts of startup where ICRH is necessary. The ability of ICRH to couple power int… more

Date: May 1, 1982

Creator: Molvik, A.W. & Falabella, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High resolution difference schemes for compressible gas dynamics

The advantages and disadvantages of four new high-resolution difference schemes, namely the von Neumann-Richtmyer, Godunovs, MUSCL and Glimms, for mathematically representing physical conditions in compressible gas flows are compared. (LCL)

Date: July 30, 1980

Creator: Woodward, P. & Colella, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Is the two-term expansion valid for highly anisotropic systems. The Townsend ionization coefficient in strong runaway as a test case

The Townsend ionization coefficient in the strong runaway regime is calculated within the framework of the two-term expansion. Results are compared to the 1-D model. General features of the two models are qualitatively similar, but quantitative differences by factors of approx. 2 are observed.

Date: July 15, 1982

Creator: Yu, S. S. & Melendez, R. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department