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Numerics for the simulation of electromagnetic-field propagation in nonionized and plasma media (open access)

Numerics for the simulation of electromagnetic-field propagation in nonionized and plasma media

The numerical techniques used to simulate the propagation of low-frequency electromagnetic disturbances in Ohmic media and in collisional and collisionless plasmas are discussed. The scheme is based upon a multimedia propagation equation that is derived from Maxwell's equations. 10 refs., 5 figs.
Date: March 1, 1986
Creator: Borovsky, J.E.
Object Type: Report
System: The UNT Digital Library
Effect of inflation on anisotropic cosmologies (open access)

Effect of inflation on anisotropic cosmologies

The effects of anisotropic cosmologies on inflation are studied. By properly formulating the field equations it is possible to show that any model that undergoes sufficient inflation will become isotropic on scales greater than the horizon today. Furthermore, we shall show that it takes a very long time for anisotropies to become visible in the observable part of the Universe. It is interesting to note that the time scale will be independent of the Bianchi Model and of the initial anisotropy. 6 refs.
Date: March 1, 1986
Creator: Jensen, L.G. & Stein-Schabes, J.A.
Object Type: Report
System: The UNT Digital Library
Finite Temperature Instability for Compactification (open access)

Finite Temperature Instability for Compactification

We consider finite temperature effects upon theories with extra dimensions compactified via vacuum stress energy (Casimir) effects. For sufficiently high temperature, a static configuration for the internal space is impossible. At somewhat lower temperatures, there is an instability due to thermal fluctuations of radius of the compact dimensions. For both cases, the Universe can evolve to a de Sitter-like expansion of all dimensions. Stability to late times constrains the initial entropy of the universe. 28 refs., 1 fig., 2 tabs.
Date: March 1, 1986
Creator: Accetta, F. S. & Kolb, E. W.
Object Type: Report
System: The UNT Digital Library
Conversion of forest residues to a methane-rich gas. Detailed economic feasibility study (open access)

Conversion of forest residues to a methane-rich gas. Detailed economic feasibility study

An economic evaluation of the application of the multi-solid fluid reactor design to wood gasification was completed. The processing options examined include plant capacity, production of a high-Btu (1006 Btu/SCF HHV) gas versus an intermediate-Btu gas (379 Btu/SCF HHV), and operating pressure. 9 figs., 29 tabs.
Date: March 1, 1986
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Review of the Oconee-3 probabilistic risk assessment: external events, core damage frequency. Volume 2 (open access)

Review of the Oconee-3 probabilistic risk assessment: external events, core damage frequency. Volume 2

A review of the Oconee-3 Probabilistic Risk Assessment (OPRA) was conducted with the broad objective of evaluating qualitatively and quantitatively (as much as possible) the OPRA assessment of the important sequences that are ''externally'' generated and lead to core damage. The review included a technical assessment of the assumptions and methods used in the OPRA within its stated objective and with the limited information available. Within this scope, BNL performed a detailed reevaluation of the accident sequences generated by internal floods and earthquakes and a less detailed review (in some cases a scoping review) for the accident sequences generated by fires, tornadoes, external floods, and aircraft impact. 12 refs., 24 figs., 31 tabs.
Date: March 1, 1986
Creator: Hanan, N. A.; Ilberg, D.; Xue, D.; Youngblood, R.; Reed, J. W.; McCann, M. et al.
Object Type: Report
System: The UNT Digital Library
Stress relaxation of cellular silicone material: 1984 (open access)

Stress relaxation of cellular silicone material: 1984

The long-term (10 years) stress relaxation properties of cellular silicone materials at room temperature are under evaluation. Both equilibrium (random copolymer) and condensation- (block copolymer) type base polymers are included. The equilibrium-type material used urea as the leachable filler, and the condensation-type material used ammonium chloride. Each material was compounded to yield densities of 0.34 and 0.52 g/cm/sup 3/ for thicknesses of 1.17, 1.52, and 2.54 mm. These density-thickness combinations were compressed to nominal compressions of 20 and 40% with nine replicates at each condition. A specially designed fixture was used to maintain a specific compression on the cellular sample, and a universal test machine acquired the load data. Currently, the predicted load retention is between 60 and 68% of the original load.
Date: March 1, 1986
Creator: Schneider, J. W.
Object Type: Report
System: The UNT Digital Library
Status report on the Livermore-Rockefeller-Fermilab neutrino mass experiment (open access)

Status report on the Livermore-Rockefeller-Fermilab neutrino mass experiment

An experiment is being performed to determine the electron neutrino mass with the precision of a few eV by measuring the tritium beta decay energy distribution near the endpoint. Key features of the experiment are a 2 eV resolution electrostatic spectrometer and a high-activity frozen tritium source.
Date: March 1, 1986
Creator: Fackler, O.; Mugge, M.; Sticker, H.; White, R.M. & Woerner, R.
Object Type: Article
System: The UNT Digital Library
Introduction to the nonlinear dynamics arising from magnetic multipoles (open access)

Introduction to the nonlinear dynamics arising from magnetic multipoles

A Hamiltonian is derived describing transverse particle motion in a storage ring. After a transformation to ''action-angle'' variables we show how to apply Green's function techniques to do Lie transform perturbation theory on this Hamiltonian. Two examples are worked out to second order: (1) normal and skew quadrupole field errors; and (2) normal sextupoles. A brief discussion of the single resonance term Hamiltonian includes derivations of the two invariants and calculation of the resonance width for one degree of freedom systems. Finally, we generalize Courant's treatment of modulational diffusion as an illustrative application of Chirikov's criterion to a multi-resonance problem. 29 refs., 3 figs.
Date: March 1, 1986
Creator: Michelotti, L.
Object Type: Article
System: The UNT Digital Library
Plasma processes in non-ideal plasmas (open access)

Plasma processes in non-ideal plasmas

Non-ideal plasma equation of state, radiative cross-sections and energy exchange coefficients are described in a tutorial overview.
Date: March 1, 1986
Creator: More, R.M.
Object Type: Article
System: The UNT Digital Library
New electronically black neutron detectors (open access)

New electronically black neutron detectors

Two neutron detectors are described that can function in a continuous radiation background. Both detectors identify neutrons by recording a proton recoil pulse followed by a characteristic capture pulse. This peculiar signature indicates that the neutron has lost all its energy in the scintillator. Resolutions and efficiencies have been measured for both detectors.
Date: March 1, 1986
Creator: Drake, D.M.; Feldman, W.C. & Hurlbut, C.
Object Type: Report
System: The UNT Digital Library
Joint DOE/NRC field study of tracer migration in the unsaturated zone (open access)

Joint DOE/NRC field study of tracer migration in the unsaturated zone

The results of a joint DOE/NRC field experiment to evaluate leaching and transport of solutes in a sandy silt backfill used for shallow land burial operations at Los Alamos are presented for steady-state and unsteady-state flow conditions. The migration of iodide, bromide, and lithium through the backfill material is studied as functions of depth and time and they are compared with one another. The bromide and iodide tracer data are used to estimate the diffusion coefficient, the tortuosity factor, and dispersivity. These values are used to calculate effective dispersion coefficients for subsequent analyses of the retardation factor and the distribution coefficient for lithium using least squares procedures. The results of the tracer migration study are discussed relative to challenges facing the waste management community, and chemical transport modeling opportunities are presented for a modeling workshop to be held in FY86.
Date: March 1, 1986
Creator: Nyhan, J.; Polzer, W.; Essington, E.; Cokal, E.; Lane, L.; Lopez, E. et al.
Object Type: Report
System: The UNT Digital Library
Shippingport operations with the Light Water Breeder Reactor core. (open access)

Shippingport operations with the Light Water Breeder Reactor core.

This report describes the operation of the Shippingport Atomic Power Station during the LWBR (Light Water Breeder Reactor) Core lifetime. It also summarizes the plant-oriented operations during the period preceding LWBR startup, which include the defueling of The Pressurized Water Reactor Core 2 (PWR-2) and the installation of the LWBR Core, and the operations associated with the defueling of LWBR. The intent of this report is to examine LWBR experience in retrospect and present pertinent and significant aspects of LWBR operations that relate primarily to the nuclear portion of the Station. The nonnuclear portion of the Station is discussed only as it relates to overall plant operation or to unusual problems which result from the use of conventional equipment in radioactive environments. 30 refs., 69 figs., 27 tabs.
Date: March 1, 1986
Creator: Budd, W. A.
Object Type: Report
System: The UNT Digital Library
Design and implementation of a control system for a deuterium pellet injector (open access)

Design and implementation of a control system for a deuterium pellet injector

The Oak Ridge National Laboratory is currently developing a Deuterium Pellet Injector for installation on the Tokamak Fusion Test Reactor (TFTR). This paper describes the design and development of a stand-alone data acquisition and control system for that device. Major elements of the hardware are an Allen-Bradley PLC 2/30 programmable logic controller, a MicroVAX-II computer using the VMS operating system, CAMAC data acquisition and communication equipment, and special-purpose controllers for temperature and for the sequencing of pellet firing valves. The PLC performs all actual control actions and acquires data pertinent to those actions. The MicroVAX receives the data acquired by the PLC, displays it for the operator, prompts for and processes requests for action from the operator, and informs the PLC of those requests. The primary purpose of this paper is to describe the software operating in the MicroVAX, including the system architecture, major tasks, and ancillary and background tasks.
Date: March 1, 1986
Creator: Burris, R. D.; Baylor, L. R.; Greenwood, D. E. & Stewart, K. A.
Object Type: Article
System: The UNT Digital Library
Fusion product measurements of the local ion thermal diffusivity in the PLT tokamak (open access)

Fusion product measurements of the local ion thermal diffusivity in the PLT tokamak

Measurement of the gradient of the d-d fusion rate profile in an ohmic PLT plasma is used to deduce the gradient of the ion temperature and, thus, the local ion thermal diffusivity through an energy balance analysis. The inferred ion diffusivity is consistent with neoclassical theory.
Date: March 1, 1986
Creator: Heidbrink, W. W.; Lovberg, J.; Strachan, J. D. & Bell, R. E.
Object Type: Report
System: The UNT Digital Library
Question of consistent boundary conditions when simulating reversed field pinch dynamics. Revision 1 (open access)

Question of consistent boundary conditions when simulating reversed field pinch dynamics. Revision 1

The issue of proper boundary conditions when performing magnetohydrodynamic simulations of the reversed field pinch is examined. Of particular concern is the choice of constant current, which when combined with other commonly used boundary conditions, may, under careless implementation, lead to an inconsistency. It is shown that this may cause erroneous results. Cases both with and without Hall terms are presented.
Date: March 1, 1986
Creator: Mirin, A. A.
Object Type: Report
System: The UNT Digital Library
Preliminary studies of two-phase effects on pressure transient data (open access)

Preliminary studies of two-phase effects on pressure transient data

In this paper we perform scoping calculations on the effects of two-phase zones on well pressure transients. Three different cases are considered. The first is that of a fully two-phase system (e.g. Krafla, Iceland). Some of the complexities of this type of system are discussed. The second problem is that of a single-phase liquid reservoir with a localized two-phase zone. Possible field examples include Cerro Prieto, Mexico and Baca, New Mexico, USA. We investigate the pressure transients in a well located near an isolated two-phase zone in a single-phase liquid reservoir, and compare them to type curves based upon the constant pressure approximation. The third problem considered is that of a two-phase layer overlying a single-phase liquid layer. One example of such a reservoir is the Svartsengi geothermal field in Iceland. The numerical code MULKOM is used to simulate the three cases.
Date: March 1, 1986
Creator: Cox, B.L. & Bodvarsson, G.S.
Object Type: Article
System: The UNT Digital Library
Theory of multiphoton ionization of atoms (open access)

Theory of multiphoton ionization of atoms

A non-perturbative approach to the theory of multiphoton ionization is reviewed. Adiabatic Floquet theory is its first approximation. It explains qualitatively the energy and angular distribution of photoelectrons. In many-electron atoms it predicts collective and inner shell excitation. 14 refs.
Date: March 1, 1986
Creator: Szoeke, A.
Object Type: Article
System: The UNT Digital Library
Technical assessment of critical Plasma-Materials Interaction (PMI) and High Heat Flux (HHF) issues for alternative fusion concepts (AFCs) (open access)

Technical assessment of critical Plasma-Materials Interaction (PMI) and High Heat Flux (HHF) issues for alternative fusion concepts (AFCs)

A number of approaches to fusion energy are being pursued as alternative fusion concepts (AFCs). The goal of these systems is to provide a more desirable method of producing fusion energy than the mainline programs. Some of the AFCs have both a Low Power Density (LPD) option and a High Power Density (HPD) option. A summary of representative AFC programs and their associated PMI and HHF issues is followed by the technical assessment of the critical issues. These requirements are discussed relative to the mainline and/or HPD components. The HPD options are contrasted with a tabulation of the characteristics of components for the Reversed-Field Pinch (RFP), which is representative of the HPD concept.
Date: March 1, 1986
Creator: Downing, J. N.
Object Type: Report
System: The UNT Digital Library
Effect of heat treatment and impurity concentration on some mechanical properties V-15Cr-5Ti alloy (open access)

Effect of heat treatment and impurity concentration on some mechanical properties V-15Cr-5Ti alloy

The effects of heat treatment and O, N, C, Si, and S impurity level on the yield strength, ductility, and fracture mode for specimens from four different heats of the V-15Cr-5Ti alloy are presented. The heat treatments for the alloy consisted of annealing as-rolled material for one hour at either 950, 1050, 1125, or 1200/sup 0/C. The total oxygen, nitrogen, and carbon impurity concentration ranged from 400 to 1200 wppm. The Si concentration ranged from 300 to 1050 wppm, and the S concentration ranged from 440 to 1100 wppm. The yield strength and ductility for the alloy, regardless of impurity concentration, exhibited minimum and maximum values, respectively, for the 1125/sup 0/C anneal. The primary mode of failure for the tensile specimens was transgranular fracture.
Date: March 1, 1986
Creator: Loomis, B. A.; Kestel, B. J. & Diercks, D. R.
Object Type: Article
System: The UNT Digital Library
Search for primarily non-interacting decay modes of the upsilon (open access)

Search for primarily non-interacting decay modes of the upsilon

The hadronic transition UPSILON(2S) ..-->.. ..pi../sup 0/..pi../sup 0/UPSILON(1S) is utilized to search for the reactions: UPSILON(1S) ..-->.. non-interacting particles and UPSILON(1S) ..-->.. ..gamma.. + non-interacting particles. 44 pb/sup -1/ of UPSILON(2S) data were taken by the Crystal Ball detector at the DORIS II storage ring in order to perform this study. An upper limit of BR(UPSILON ..-->.. Unseen) < 12% (90% C.L.), is obtained via this approach. The second process investigated involved the radiative decay of the Upsilon into non-interacting particles. 57 pb/sup -1/ of UPSILON(2S) data was available for this study. An upper limit on the branching ratio BR(UPSILON ..-->.. ..gamma.. + Unseen) is measured for photon energies in the range 500 MeV < E..gamma.. < M/sub ..gamma..//2. This is the first reported measurement of this type. For the highest energy photons, an upper limit of BR(UPSILON ..-->.. ..gamma.. + Unseen) < 2.3 x 10/sup -3/ (90% C.L.), is obtained. The compact size of the Crystal Ball detector enhances the observable branching ratio for noninteracting particles with short lifetimes such as massive axions. The identification of the recent Darmstadt events with a 1.6 MeV axion is excluded by the present result assuming the minimal Peccei-Quinn model. Limits on the …
Date: March 1, 1986
Creator: Leffler, J.S.
Object Type: Report
System: The UNT Digital Library
Design of a mixing system for simulated high-level nuclear waste melter feed slurries (open access)

Design of a mixing system for simulated high-level nuclear waste melter feed slurries

The Nuclear Waste Treatment Program development program consists of coordinated nonradioactive and radioactive testing combined with numerical modeling of the process to provide a complete basis for design and operation of a vitrification facility. The radioactive demonstration tests of equipment and processes are conducted before incorporation in radioactive pilot-scale melter systems for final demonstration. The mixing system evaluation described in this report was conducted as part of the nonradioactive testing. The format of this report follows the sequence in which the design of a large-scale mixing system is determined. The initial program activity was concerned with gaining an understanding of the theoretical foundation of non-Newtonian mixing systems. Section 3 of this report describes the classical rheological models that are used to describe non-Newtonian mixing systems. Since the results obtained here are only valid for the slurries utilized, Section 4, Preparation of Simulated Hanford and West Valley Slurries, describes how the slurries were prepared. The laboratory-scale viscometric and physical property information is summarized in Section 5, Laboratory Rheological Evaluations. The bench-scale mixing evaluations conducted to define the effects of the independent variables described above on the degree of mixing achieved with each slurry are described in Section 6. Bench-scale results are …
Date: March 1, 1986
Creator: Peterson, M.E.; McCarthy, D. & Muhlstein, K.D.
Object Type: Report
System: The UNT Digital Library
Effect of helium on swelling and microstructural evolution in ion-irradiated V-15Cr-5Ti alloy (open access)

Effect of helium on swelling and microstructural evolution in ion-irradiated V-15Cr-5Ti alloy

An investigation was made on the effects of implanted helium on the swelling and microstructural evolution that results from energetic single- and dual-ion irradiation of the V-15Cr-5Ti alloy. Single-ion irradiations were utilized for a simulated production of the irradiation damage that might be expected from neutron irradiation of the alloy in a reactor with a fast neutron energy spectrum (E > 0.1 MeV). Dual-ion irradiations were utilized for a simulated production of the simultaneous creation of helium atoms and irradiation damage in the alloy in the MFR environment. Experimental results are also presented on the radiation-induced segregation of the constituent atoms in the single- and dual-ion irradiated alloy.
Date: March 1, 1986
Creator: Loomis, B. A.; Kestel, B. J.; Gerber, S. B. & Ayrault, G.
Object Type: Article
System: The UNT Digital Library
Operational characteristic of a compact microwave ion source (open access)

Operational characteristic of a compact microwave ion source

A small microwave ion source has been fabricated from a quartz tube with one end enclosed by a two grid accelerator. The source is also enclosed by a cavity operated at a frequency of 2.45 GHz. Microwave power as high as 500 W can be coupled to the source plasma. The source has been operated with different geometries and for various gases in a cw mode. For hydrogen, ion current density of 200 mA/cm/sup 2/ with atomic ion species concentration as high as 80% has been extracted from the source. It has also been demonstrated that low energy oxygen ion beams (5 to 10 eV) can also be extracted from the source.
Date: March 1, 1986
Creator: Walther, S. R. & Leung, K. N.
Object Type: Article
System: The UNT Digital Library
Microinstability-based model for anomalous thermal confinement in tokamaks (open access)

Microinstability-based model for anomalous thermal confinement in tokamaks

This paper deals with the formulation of microinstability-based thermal transport coefficients (chi/sub j/) for the purpose of modelling anomalous energy confinement properties in tokamak plasmas. Attention is primarily focused on ohmically heated discharges and the associated anomalous electron thermal transport. An appropriate expression for chi/sub e/ is developed which is consistent with reasonable global constraints on the current and electron temperature profiles as well as with the key properties of the kinetic instabilities most likely to be present. Comparisons of confinement scaling trends predicted by this model with the empirical ohmic data base indicate quite favorable agreement. The subject of anomalous ion thermal transport and its implications for high density ohmic discharges and for auxiliary-heated plasmas is also addressed.
Date: March 1, 1986
Creator: Tang, W.M.
Object Type: Report
System: The UNT Digital Library