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Impulsive ion acceleration in earth's outer magnetosphere
Considerable observational evidence is found that ions are accelerated to high energies in the outer magnetosphere during geomagnetic disturbances. The acceleration often appears to be quite impulsive causing temporally brief (10's of seconds), very intense bursts of ions in the distant plasma sheet as well as in the near-tail region. These ion bursts extend in energy from 10's of keV to over 1 MeV and are closely associated with substorm expansive phase onsets. Although the very energetic ions are not of dominant importance for magnetotail plasma dynamics, they serve as an important tracer population. Their absolute intensity and brief temporal appearance bespeaks a strong and rapid acceleration process in the near-tail, very probably involving large induced electric fields substantially greater than those associated with cross-tail potential drops. Subsequent to their impulsive acceleration, these ions are injected into the outer trapping regions forming ion ''drift echo'' events, as well as streaming tailward away from their acceleration site in the near-earth plasma sheet. Most auroral ion acceleration processes occur (or are greatly enhanced) during the time that these global magnetospheric events are occurring in the magnetotail. A qualitative model relating energetic ion populations to near-tail magnetic reconnection at substorm onset followed by …
Date:
January 1, 1985
Creator:
Baker, D.N. & Belian, R.D.
Object Type:
Article
System:
The UNT Digital Library
Magnetic field, closed orbit, and energy measurement in the Bevatron
This report provides the information necessary for a better evaluation of particle energy in the Bevatron. Previously, the nominal magnetic field value and radius were used to calculate the value for the kinetic energy of the particle. This value was good to a few percent. Today, more and more experimenters would like to know the energy to a more precise value. To this end, corrections to the measured magnetic field values and the radial closed orbit are provided.
Date:
November 1, 1981
Creator:
Crebbin, K. C.
Object Type:
Report
System:
The UNT Digital Library
HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report
Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should …
Date:
September 1, 1982
Creator:
Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W et al.
Object Type:
Report
System:
The UNT Digital Library
Quantitative analysis of the hydrothermal system in Lassen Volcanic National Park and Lassen Known Geothermal Resource Area
The Lassen hydrothermal system is in the southern Cascade Range, approximately 70 kilometers east-southeast of Redding, California. The conceptual model of the Lassen system is termed a liquid-dominated hydrothermal system with a parasitic vapor-dominated zone. The essential feature of this model is that steam and steam-heated discharge at relatively high elevations in Lassen Volcanic National Park (LVNP) and liquid discharge with high chloride concentrations at relatively low elevations outside LVNP in the Lassen Known Geothermal Resource Area (KGRA) are both fed by an upflow of high-enthalpy, two-phase fluid within the Park. Liquid flows laterally away from the upflow area towards the areas of high-chloride discharge, and steam rises through a vapor-dominated zone to feed the steam and steam-heated features. The geometric model corresponds to an areally restricted flow regime that connects the Bumpass Hell area in LVNP with regions of chloride hot springs in the Mill Creek canyon in the KGRA south of LVNP. Simulations of thermal fluid withdrawal in the Mill Creek Canyon were carried out in order to determine the effects of such withdrawal on portions of the hydrothermal system within the Park. 19 refs., 17 figs., 4 tabs.
Date:
January 1, 1984
Creator:
Sorey, M.L. & Ingebritsen, S.E.
Object Type:
Report
System:
The UNT Digital Library
Boron reclamation
A process to recover high purity /sup 10/B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron is recovered in the form of boric acid. The minimum purity requirement of the recovered product is 98.6 percent total boron.
Date:
July 1, 1980
Creator:
Smith, R. M.
Object Type:
Report
System:
The UNT Digital Library
Proceedings of the LAMPF workshop on physics with polarized nuclear targets
Topics of discussion included static and dynamic methods for polarizing nuclei, proton and pion nucleus scattering experiments, and possible future experiments at LAMPF. Separate abstracts were prepared for 11 papers in this report. (DWL)
Date:
August 1, 1986
Creator:
Burleson, G.; Gibbs, W.; Hoffmann, G.; Jarmer, J. J. & Tanaka, N. (eds.)
Object Type:
Article
System:
The UNT Digital Library
ETRANS: an energy transport system optimization code for distributed networks of solar collectors
The optimization code ETRANS was developed at the Pacific Northwest Laboratory to design and estimate the costs associated with energy transport systems for distributed fields of solar collectors. The code uses frequently cited layouts for dish and trough collectors and optimizes them on a section-by-section basis. The optimal section design is that combination of pipe diameter and insulation thickness that yields the minimum annualized system-resultant cost. Among the quantities included in the costing algorithm are (1) labor and materials costs associated with initial plant construction, (2) operating expenses due to daytime and nighttime heat losses, and (3) operating expenses due to pumping power requirements. Two preliminary series of simulations were conducted to exercise the code. The results indicate that transport system costs for both dish and trough collector fields increase with field size and receiver exit temperature. Furthermore, dish collector transport systems were found to be much more expensive to build and operate than trough transport systems. ETRANS itself is stable and fast-running and shows promise of being a highly effective tool for the analysis of distributed solar thermal systems.
Date:
September 1, 1980
Creator:
Barnhart, J.S.
Object Type:
Report
System:
The UNT Digital Library
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 the vacuum vessel. Bellows are used to keep essentially all of the mechanism isolated from the vessel vacuum. The bellows come in two sizes (8.25'' O.D. and 14'' O.D.). The smaller of the two bellows has been qualified by testing up to 94,000 cycles by empirically adjusting details of the bellow design (geometry and thickness). The process required 12 different test samples and took over a one-year period to accomplish. The bellows consistently failed in the inside diameter weld heat-affected zone. Results from stress analysis studies are presented.
Date:
April 1, 1982
Creator:
Tokarz, F. J.; Johnson, J. J.; Mukherjee, A. N. & Dalder, E. N.
Object Type:
Report
System:
The UNT Digital Library
Relativistic effects in the atomic and nuclear few-body problems
Relativistic effects in the atomic and nuclear few-body systems are classified and discussed with the emphasis on electromagnetic transitions. The size of relativistic corrections, calculational techniques and ambiguities, and comparison of theory and experiment are considered. 8 figures.
Date:
January 1, 1980
Creator:
Friar, J.L.
Object Type:
Article
System:
The UNT Digital Library
Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report
The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.
Date:
April 11, 1980
Creator:
Clifford, J E & Diegle, R B
Object Type:
Report
System:
The UNT Digital Library
850/sup 0/C VHTR plant technical description
This report describes the conceptual design of an 842-MW(t) process heat very high temperature reactor (VHTR) plant having a core outlet temperature of 850/sup 0/C (1562/sup 0/F). The reactor is a variation of the high-temperature gas-cooled reactor (HTGR) power plant concept. The report includes a description of the nuclear heat source (NHS) and of the balance of reactor plant (BORP) requirements. The design of the associated chemical process plant is not covered in this report. The reactor design is similar to a previously reported VHTR design having a 950/sup 0/C (1742/sup 0/F) core outlet temperature.
Date:
June 1, 1980
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Western Gas Sands Project. Status report, 1 May-31 May, 1980
This report summarizes the progress of the government-sponsored project directed towards increasing gas production from the low permeability gas sands of the western United States. The planning activities for the multi-well experiment continued in May. Bartlesville Energy Technology Center continued formation evaluation and reservoir simulation studies. Lawrence Livermore Laboratory continued calculations of fracturing near interfaces. Los Alamos Scientific Laboratory focused work on the permanent magnet system for NMR logging. Results of the 3-D Seismic Reflection Survey were presented by Sandia Laboratories. Production and injection experiments continued for the Colorado Interstate Gas Company Miller No. 1 and Sprague No. 1 wells. The DOE Well Test Facility was transported to Las Vegas for repairs and modifications. In situ testing continued at the Nevada Test Site for the Sandia Mineback program.
Date:
January 1, 1980
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Microcrystalline silicon growth for heterojunction solar cells. Second quarterly report, 1 April 1983-30 June 1983
In this reporting period, a single source of evaporation with B mixed with highly doped Si was used instead of the co-evaporation of separate Si and B sources. The purpose was to reduce possible carbon contamination. The results of both the heterojunction or heteroface structures, however, were similar to last quarter when evaporation was used. The best Voc of the heterojunction was about 460mV and no improvement in Voc in the heteroface structure, was observed; slight Voc degradation occurred. A study of the p m-Si/p c-Si structure showed a negative Voc in many cases. The highest /sup 0/C voltage was up to -150mV. This indicated that the interface properties between the two materials are such that instead of repelling minority carriers from the substrate carrier, collection actually occurred. This structure defeated the purpose, but it might also mean that n-type m-Si could be beneficial and should be included in future study. Another study of cells made in the part of substrates not covered by m-Si resulted in performance lower than the controls. This indicated possible substrate degradation in the process, the extent of which will be studied in the future.
Date:
January 1, 1983
Creator:
Iles, P. A.; Leung, D. C. & Fang, P. H.
Object Type:
Report
System:
The UNT Digital Library
Physical simulations of cavity closure in a creeping material
The finite element method has been used extensively to predict the creep closure of underground petroleum storage cavities in rock salt. Even though the numerical modeling requires many simplifying assumptions, the predictions have generally correlated with field data from instrumented wellheads, however, the field data are rather limited. To gain an insight into the behavior of three-dimensional arrays of cavities and to obtain a larger data base for the verification of analytical simulations of creep closure, a series of six centrifuge simulation experiments were performed using a cylindrical block of modeling clay, a creeping material. Three of the simulations were conducted with single, centerline cavities, and three were conducted with a symmetric array of three cavities surrounding a central cavity. The models were subjected to body force loading using a centrifuge. For the single cavity experiments, the models were tested at accelerations of 100, 125 and 150 g's for 2 hours. For the multi-cavity experiments, the simulations were conducted at 100 g's for 3.25 hours. The results are analyzed using dimensional analyses. The analyses illustrate that the centrifuge simulations yield self-consistent simulations of the creep closure of fluid-filled cavities and that the interaction of three-dimensional cavity layouts can be investigated …
Date:
September 1, 1985
Creator:
Sutherland, H.J. & Preece, D.S.
Object Type:
Report
System:
The UNT Digital Library
De-entrainment on vertical elements in air droplet cross flow. [PWR]
De-entrainment phenomena on vertical elements in air-water droplet cross flow are generated using a horizontal array of water spray nozzles and a draft-induced wind tunnel. These conditions are used to obtain experimental values of the de-entrainment efficiency of isolated elements (25.4-, 63.5-, and 101.6-mm-diam cylinders and a 76.2-mm-square tube), and of an array of 101.6-mm-diam cylinders. A flow model is developed that extrapolates the de-entrainment efficiency of isolated elements through the use of a correlation for the interference effect to predict the efficiency of large arrays of similar elements. This simple model is shown to provide a good prediction of the de-entrainment efficiency of arrays in terms of the efficiency of an isolated element.
Date:
January 1, 1980
Creator:
Dallman, J.C. & Kirchner, W.L.
Object Type:
Article
System:
The UNT Digital Library
Fifth high-energy heavy-ion study
This was the fifth of a continuing series of summer studies held at LBL to discuss high energy heavy ion collisions. Recently, a similar meeting has been held on alternate years at GSI (Darmstadt); and, in 1979, we held a meeting at LBL exclusively devoted to ultra-relativistic nuclear collisions. Two new features distinguish this study from earlier meetings in the series. First, the energy range for discussion was broadened by including collisions from about 20 MeV/nucleon to the highest available in the cosmic radiation. The lower range, particularly below 100 MeV/nucleon, will be under intense study in the near future with machines such as the upgraded Bevalac, Michigan State University Superconducting Cyclotron, GANIL in France, and the SC at CERN. Recently, the high energy collision regime has been expanded by the successful operation of the CERN ISR with alpha particles. Second, in addition to an extensive program of invited talks, we decided for the first time to actively solicit contributions. Forty-seven individual items from the conference were prepared separately for the data base. (GHT)
Date:
October 1, 1981
Creator:
unknown
Object Type:
Article
System:
The UNT Digital Library
Pacific Northwest Laboratory, annual report for 1983 to the DOE Office of Energy Research. Part 4. Physical sciences
Part 4 of the Pacific Northwest Laboratory Annual Report for 1983 to the Office of Energy Research, includes those programs funded under the title Physical and Technological Research. The Field Task Program Studies reports in this document are grouped under the subheadings and each section is introduced by a divider page that indicates the Field Task Agreement reported in that section. These reports only briefly indicate progress made during 1983. The reader should contact the principal investigators named or examine the publications cited for more details.
Date:
February 1, 1984
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Catalyst and process development for hydrogen preparation from future fuel cell feedstocks. Quarterly progress report, October 1, 1979-December 31, 1979. [Pt/Rh, Ni/Rh, Ni/Pt/Rh, Ni, Ni/Ru, Ni/Pt, Ni/Co]
Twelve steam reforming catalysts were evaluated using an autothermal reforming screening unit. Duplicate tests were run with two samples to determine test variability. The samples tested contained either base metals, precious metals, or combinations of base and precious metals. The test was capable of distinguishing among samples where gross variations in composition are the main factor; for example, catalysts containing 2% by weight precious metals are more active than catalysts containing 15% by weight nickel. The results show a decrease in hydrocarbon breakthrough as the weight of nickel charged to the constant volume reactor increases. A commercial nickel catalyst, G90C, appears slightly better than some Engelhard prepared samples of equal nickel concentrations due to the higher density of G90C. Visual observation of the used catalysts show that samples containing only precious metals (Pt/Rh) did not coke during the run. The samples containing only base metals (nickel, cobalt) were coked and were magnetic. Samples containing 14.5% nickel by weight with 0.5% precious metals by weight added were not coked, were not magnetic, and had a blue colored core as compared to the black core of the virgin samples. Some speculation about deactivation mechanisms based on these observations are made.
Date:
January 1, 1980
Creator:
Yarrington, R M; Feins, I R; Hwang, H S & Mayer, C P
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Article
System:
The UNT Digital Library
Coordination/management tasks for the IEA and CCMS solar heating and cooling programs
None
Date:
January 1, 1980
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Stark broadening of isolated lines from high-Z emitters in dense plasmas
The joint distribution of the electric microfield and its longitudinal derivative is required for the calculation of line profiles for the He-like ions in very dense plasmas. We used a molecular dynamics code to compute exact distributions in single- and multi-component plasmas, and then we investigated various analytical approximations to these results. We found that a simplified, two-nearest-neighbor scheme leads to surprisingly accurate distribution functions. Our results are illustrated by sample profiles for Ne/sup +8/ and Ar/sup +16/ resonance lines.
Date:
September 1, 1980
Creator:
Weisheit, J.C. & Pollock, E.L.
Object Type:
Article
System:
The UNT Digital Library
Growth regulation by macrophages
The evidence reviewed here indicates that macrophages, either acting alone or in concert with other cells, influence the proliferation of multiple types of cells. Most of the data indicate that these effects are mediated by soluble macrophage-elaborated products (probably proteins) although the role of direct cell-to-cell contacts cannot be ruled out in all cases. A degree of success has been achieved on the biochemical characterization of these factors, due mainly to their low specific activity in conditioned medium and the lack of rapid, specific assays. Understanding the growth-regulating potential of macrophages is an important and needed area of research.
Date:
January 1, 1982
Creator:
Wharton, W.; Walker, E. & Stewart, C.C.
Object Type:
Article
System:
The UNT Digital Library
Diskless LSI-11 systems
Programs for dedicated LSI-11 based systems can easily be stored in ROM instead of floppy disks, yet execute the same as disk-stored programs. Two sample systems are described.
Date:
January 1, 1982
Creator:
Ford, W. & Shirk, D. G.
Object Type:
Article
System:
The UNT Digital Library
Severe accident core heatup transients in modular high temperature gas-cooled reactors without operating Reactor Cavity Cooling Systems
The ultimate decay heat removal system for the current Modular High Temperature Gas-Cooled reactors is a completely passive natural convection air cooling loop. This paper considers an extremely remote accident scenario, where even this passive system fails, and heat rejection is only via a layer of thermal insulation to the reactor silo structure and the surrounding soil. The results show that even in this case the peak fuel temperatures remain well within safe limits. However, vessel and concrete temperatures can - under extreme circumstances and after several weeks - reach temperature levels at which structural failure becomes possible.
Date:
January 1, 1988
Creator:
Kroeger, P. G.
Object Type:
Article
System:
The UNT Digital Library