744 Matching Results

Search Results

Advanced search parameters have been applied.

in subjects: "Electric Potential"

open access

ORMAK upgrade ohmic coil generator protection

This report describes methods which can be used to limit the voltage across the generator for normal operation and various ground faults. It also contains quantitative information, obtained from the computer study, which can be used for evaluating the protection methods cost-wise.

Date: January 1, 1978

Creator: Campen, G. L.; Easter, R. B. & Nickels, L. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Thermonuclear inverse magnetic pumping power cycle for stellarator reactors

A novel power cycle for direct conversion of alpha-particle energy into electricity is proposed for an ignited plasma in a stellarator reactor. The plasma column is alternately compressed and expanded in minor radius by periodic variation of the toroidal magnetic field strength. As a result of the way a stellarator is expected to work, the plasma pressure during expansion is greater than the corresponding pressure during compression. Therefore, negative work is done on the plasma during a compl… more

Date: September 1, 1985

Creator: Ho, D.D.M. & Kulsrud, R.M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

TRANSIENT RADIATION EFFECTS IN CAPACITORS AND DIELECTRIC MATERIALS

Measurements of dielectric leakage, capacitance, electric strength, andd charge scattering phenomena were performed at the Kukla and Godiva III critical assemblies for tantalum and aluminum electrolytic, wax- and oilimpregnated paper, mylar, mica, and ceramic capacitors, and for mylar and Vitamin B-impregnated paper. Leakage data indicate that gamma induced conductivity in capacitor dielectric varies directly with gamma DELTA , where gamma is the gamma radiation rate and DELTA is 0.9 for mylar,… more

Date: August 15, 1961

Creator: Wicklein, H. W. & Dickhaut, R. H.

Item Type: Book

Partner: UNT Libraries Government Documents Department

open access

ORNL TNS program: microwave start-up of tokamak plasmas near electron cyclotron and upper hybrid resonances

The scenario of toroidal plasma start-up with microwave initiation and heating near the electron cyclotron frequency is suggested and examined here. We assume microwave irradiation from the high field side and an anomalously large absorption of the extraordinary waves near the upper hybrid resonance. The dominant electron energy losses are assumed to be due to magnetic field curvature and parallel drifts, ionization of neutrals, cooling by ions, and radiation by low Z impurities. It is shown by… more

Date: December 1, 1977

Creator: Peng, Y. K. M. & Borowski, S. K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Research on alkaline zinc secondary electrodes with emphasis on model testing. Final report, June 15, 1976-August 31, 1979

The goal of this work was to obtain information useful in the improvement of life and performance of alkaline secondary cells utilizing porous zinc electrodes. Toward this end, experiments designed to test predictions of the most sophisticated mathematical models of the porous zinc electrode were performed. This approach is based on the conviction that the surest way to realize a significantly longer-lived zinc electrode is through better understanding of the electrode gained through the intera… more

Date: January 1, 1979

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Tokamak startup with electron cyclotron heating

Experiments are described in which the startup voltage in a tokamak is reduced by approx. 60% by the use of a modest amount of electron cyclotron resonance heating power for preionization. A 50% reduction in volt-second requirement and impurity reflux are also observed.

Date: April 1, 1980

Creator: Holly, D. J.; Prager, S. C.; Shepard, D. A. & Sprott, J. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Determination of optimum electrolyte composition for molten carbonate fuel cells

The objective of this study is to determine the optimum electrolyte composition for molten carbonate fuel cells. To accomplish this, the contractor will provide: (1) Comprehensive reports of on-going efforts to optimize carbonate composition. (2) A list of characteristics affected by electrolyte composition variations (e.g. ionic conductivity, vapor pressure, melting range, gas solubility, exchange current densities on NiO, corrosion and cathode dissolution effects). (3) Assessment of the overa… more

Date: January 1, 1986

Creator: Pigeaud, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Plasma-Induced Conversion of Surface-Adsorbed Hydrocarbons

Experimental results are reported for an electrical device for direct conversion of methane into higher hydrocarbons. A microchannel plate is excited with electrons from a photoemissive source, and electron impact ionization of methane on the inner surfaces of the microchannels creates an ion feedback process. The resulting low-density plasma creates higher hydrocarbons when charged particles impact the surfaces at grazing incidence. The production Of C{sub 2} to C{sub 8}-containing gases was n… more

Date: January 1, 1992

Creator: Sackinger, W. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

RF voltage modulation at discrete frequencies with applications to crystal channeling extraction

RF voltage modulation at a finite number of discrete frequencies is described in a Hamiltonian resonance framework. The theory is applied to the problem of parasitic extraction of a fixed target beam from a high energy proton collider, using a bent crystal as a thin septum'' within an effective width of about one micron. Three modes of employment of discrete resonances are proposed.First, a single relatively strong static drive'' resonance may be used to excite a test proton so that it will pen… more

Date: May 1, 1992

Creator: Gabella, W.; Rosenzweig, J. (California Univ., Los Angeles, CA (United States). Dept. of Physics); Kick, R. (Illinois Math and Science Academy, Aurora, Illinois (United States)) & Peggs, S. (Fermi National Accelerator Lab., Batavia, IL (United States))

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Precision programmable bipolar V/f instrumentation module

A precision bipolar voltage-to-frequency converter, which is computer-programmable from a digital interface, has been produced. Utilizing NIM packaging, the 1 MHz V/f has sixteen ranges and may be operated from panel controls as well as remotely programmed. Intended for use in magnetic measurements, good performance and versatility suggest wider application. The instrument is described and the circuit design is discussed in detail. Tests of the first unit are discussed and instrument specificat… more

Date: October 1, 1981

Creator: Hearn, W. E.; Green, M. I.; Nelson, D. H. & Rondeau, D. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Modeling requirements for in situ vitrification

This document outlines the requirements for the model being developed at the INEL which will provide analytical support for the ISV technology assessment program. The model includes representations of the electric potential field, thermal transport with melting, gas and particulate release, vapor migration, off-gas combustion and process chemistry. The modeling objectives are to (1) help determine the safety of the process by assessing the air and surrounding soil radionuclide and chemical poll… more

Date: November 1, 1991

Creator: MacKinnon, R.J.; Mecham, D. C.; Hagrman, D. L.; Johnson, R. W.; Murray, P. E.; Slater, C. E. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Radiation-induced electrical breakdown of helium in fusion reactor superconducting magnet systems

A comprehensive theoretical study has been performed on the reduction of the electrical breakdown potential of liquid and gaseous helium under neutron and gamma radiation. Extension of the conventional Townsend breakdown theory indicates that radiation fields at the superconducting magnets of a typical fusion reactor are potentially capable of significantly reducing currently established (i.e., unirradiated) helium breakdown voltages. Emphasis is given to the implications of these results inclu… more

Date: December 2, 1983

Creator: Perkins, L.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Photovoltaic mechanisms in polycrystalline thin-film silicon solar cells

Fundamental limitations on the performance of Si solar cells are shown to be quite different from those that have been conventionally invoked. Particularly for heavy-doping effects, the usual models are shown to be invalid and a new method is devised for calculating the reverse saturation current of a heavily doped device in which nearly all minority carriers reach the junction (viz., good blue-response). Calculations by the new method show: (1) increased doping above 10/sup 18/cm/sup -3/ does … more

Date: February 1, 1980

Creator: Redfield, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Improved vacuum surface flashover performance of polymer insulators by the use of unique triple junction designs

Previous research and theories about surface flashover in vacuum indicate that the triple junction region plays a critical role in the insulator flashover process. To attempt to improve upon the performance of the standard 45-degree frustum insulator, three different insulator geometries with modified triple junction regions were investigated. Two samples of each geometry, each 2 cm thick, were tested to obtain the flashover voltage levels in a low 10{sup {minus}5} Torr vacuum using a 1.2-micro… more

Date: January 1, 1991

Creator: Smith, J. D.; Kahaian, D. J.; Honig, E. M.; Montoya, R. E.; Rosocha, L. A.; Allen, G. R. (Los Alamos National Lab., NM (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Analysis of electron transport in the plasma of thermionic converters

Electron transport coefficients of a gaseous ensemble are expressed analytically as function of density, and are expressed analytically as function of temperature up to an unknown function which has to be evaluated for each specific electron-neutral atom cross section. In order to complete the analytical temperature dependence one may introduce a polynomial expansion of the function or one may derive the temperature dependence of a set of coefficients, numbering thirteen for a third approximati… more

Date: March 1, 1980

Creator: Stoenescu, M.L. & Heinicke, P.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Evaluation and verification of epitaxial process sequence for silicon solar-cell production. Final program summary report

Progress, present status, and data are presented for work in the areas of silicon substrate materials epitaxial substrates and epitaxial growth and of solar cells production process sequence determination especially, and also in the areas of process specification, minimodule design, process and design verification, and cost evaluation and projections. (LEW)

Date: November 1, 1981

Creator: Redfield, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Automatic voltage-imbalance detector

A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Date: May 20, 1981

Creator: Bobbett, R. E.; McCormick, J. B. & Kerwin, W. J.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

open access

Improvement of the high voltage properties of the Fermilab electrostatic septa

In the Fermilab Tevatron Switchyard proton beam splits ae initiated by a wire array electrostatic septum. At 1 TeV energy, and with fields limited to 50 kV/cm, an electrostatic septum more than 20 meters in length is required to produce the required angular separation between the beams for the Proton and Neutrino/Meson lines. New techniques have been investigated that will allow reliable operation at fields above 75 kV/cm with resultant beam line economy. Changes in construction and conditionin… more

Date: June 1, 1985

Creator: Trbojevic, D.; Crawford, C.; Childress, S. & Tinsley, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fuel cell applied research: electrocatalysis and materials. Quarterly report, January 1-March 31, 1979

In situ regeneration of surface areas of sintered carbon supported platinum electrodes in 85% H/sub 3/PO/sub 4/ at 150/sup 0/C was studied. The kinetics of oxygen reduction on platinum in trifluoromethane sulfonic acid was investigated. Overpotentials in solid oxide electrolyte fuel cells were studied. Results are presented and discussed. Also, a survey of the status of studies of phosphoric acid and molten carbonate fuel cells is described. (WHK)

Date: October 1, 1979

Creator: Srinivasan, S.; Isaacs, H. S.; McBreen, J.; O'Grady, W. E.; Olender, H.; Olmer, L. J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Model for the crosscoupling parameters of rocks

The self-potential method of geothermal exploration is based on the measurement of naturally occurring electrical potentials generated by flows of fluid (electrokinetic) and heat (thermoelectric) through rocks. The interpretation of self-potential measurements by modeling requires a knowledge of crosscoupling parameters of geological materials. In general there is a paucity of such data and one of the largest compilations of crosscoupling parameters consists of data on only 40 samples. Much mor… more

Date: June 1, 1982

Creator: Sill, W.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Noise characterization of the linear CCD

Work in evaluating the noise performance of the linear charge-coupled devices (CCD) is summarized. The noise determines the minimum amplitude signal the CCD is capable of capturing and therefore is one of the prime parameters in determining dynamic range. The noise after correlated double sampling and correction of some ground loops will be shown equivalent to 150 rms electrons at the floating diffusion sensor on the CCD.

Date: May 1, 1980

Creator: McConaghy, C. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Tandem mirror reactors with thermal barriers

Preliminary calculations of Q and magnet designs are presented for three different versions of tandem mirror reactors (TMR) using thermal barriers to enhance plug potentials by auxiliary electron heating. These three versions, called A-cell-barrier TMR, axisymmetric-barrier TMR, and inside-barrier TMR, exhibit reduced plug density (n/sub p/ << 10/sup 19/ m/sup -3/) and less required magnetic mirror field (B/sub mirror approx. = 9 T) compared to TMR designs without thermal barriers. A-cell barri… more

Date: May 23, 1980

Creator: Logan, B. G.; Arfin, B. & Barr, W. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design and fabrication of an ion accelerator for TFTR-type neutral beam systems

The design of the prototype 120-keV, 65-A, 0.5-sec ion accelerator for TFTR-type beam systems is described. Details of the manufacture of the constituent parts are given along with descriptions of the major components of the accelerator. Included are the molybdenum grid structures, molybdenum shields, stainless steel hats and the epoxy insulator. Specific manufacturing problems are discussed along with the results of tests to determine the voltage holding capabilities of the assembly.

Date: October 1, 1977

Creator: Paterson, J.A.; Duffy, T.J.; Haughian, J.M.; Biagi, L.A. & Yee, D.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Simulation and Simplified Design Studies of Photovoltaic Systems

Results of TRNSYS simulations of photovoltaic systems with electrical storage are described. Studies of the sensitivity of system performance, in terms of the fraction of the electrical load supplied by the solar energy system, to variables such as array size, battery size, location, time of year, and load shape are reported. An accurate simplified method for predicting array output of max-power photovoltaic systems is presented. A second simplified method, which estimates the overall performan… more

Date: September 1980

Creator: Evans, D. L.; Facinelli, W. A. & Koehler, L. P.

Item Type: Report

Partner: UNT Libraries Government Documents Department