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5,590 Matching Results

Start Over Access Open Access Year 1982 Day 1st

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Results: 1 - 24 of 5,590 next

(open access)

Development and evaluation of systems for controlling parallel high di/dt thyratrons

Increasing numbers of high power, high repetition rate applications dictate the use or thyratrons in multiple of hard parallel configurations to achieve the required rate of current rise, di/dt. This in turn demands the development of systems to control parallel thyratron commutation with nanosecond accuracy. Such systems must be capable of real-time, fully-automated control in multi-kilohertz applications while still remaining cost effective. This paper describes the evolution of such a control methodology and system.

Date: January 1, 1982

Creator: A., Litton. & McDuff, G.

Object Type: Article

System: The UNT Digital Library

(open access)

Role of water in energy development

One consequence of the recently increasing emphasis on energy development is public concern about the adequacy of ancillary natural resources, particularly water. This concern accompanies other water-related issues such as droughts, decling water tables, and increasing urbanization. But as the relatively new user on the water scene, energy attracts a major share of public attention. The physical availabiltiy of water and the role of economics in water demand by energy are reviewed. Also described are the social mechanisms through which the physical availability of water, the historical pattern of water use, and unresolved water issues combine to constrain and channel the energy industry's use of water. These mechanisms include the developing markets for water rights, the legal and administrative structure governing water allocation, the formation of social attidudes about water, and the political process that often implements concensus. The narrow physical interpretation commonly given to the question Is there enough water is broadened to include the social dimension, the most important component of the quenstion.

Date: January 1, 1982

Creator: Abbey, D.; Roach, F. & Brown, L.

Object Type: Article

System: The UNT Digital Library

(open access)

Review of ORNL-TSF shielding experiments for the gas-cooled Fast Breeder Reactor Program

During the period between 1975 and 1980 a series of experiments was performed at the ORNL Tower Shielding Facility in support of the shield design for a 300-MW(e) Gas Cooled Fast Breeder Demonstration Plant. This report reviews the experiments and calculations, which included studies of: (1) neutron streaming in the helium coolant passageways in the GCFR core; (2) the effectiveness of the shield designed to protect the reactor grid plate from radiation damage; (3) the adequacy of the radial shield in protecting the PCRV (prestressed concrete reactor vessel) from radiation damage; (4) neutron streaming between abutting sections of the radial shield; and (5) the effectiveness of the exit shield in reducing the neutron fluxes in the upper plenum region of the reactor.

Date: January 1, 1982

Creator: Abbott, L. S.; Ingersoll, D. T.; Muckenthaler, F. J. & Slater, C. O.

Object Type: Report

System: The UNT Digital Library

(open access)

RFQ development at LBL

The radio frequency quadrupole (FRQ) is a structure which can efficiently focus, bunch and accelerate low velocity ion beams. It has many features which make it particularly attractive for applications in the biomedical and nuclear sciences. There are two projects in progress at LBL where the incorporation of heavy ion RFQ technology offers substantial benefits: in the upgrade of the Bevatron local injector, and in the design of a dedicated heavy ion medical accelerator. In order to meet the requirements of these two important applications, a 200 MHz RFQ structure has been designed for ions with charge to mass ratios as low as 0.14, and a low rf power scale model has been built and tested. Construction of the high power model has begun. The status of this project is reviewed and a summary of technical specifications given.

Date: November 1, 1982

Creator: Abbott, S.; Brodzik, D.; Gough, R.A.; Howard, D.; Lancaster, H.; MacGill, R. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Debris-bed cooling following an HCDA in a fast reactor. Annual progress report

Natural convection within simulated core debris beds has been investigated experimentally and numerically. The objectives of this research have been: (1) to develop a three-dimensional transient model for analyzing single-phase cooling of debris beds; (2) to validate the model using out-of-pile simulant experiments which measure the detailed structure of the convection cells within the bed as well as integral heat transfer rates; and (3) to apply the model to typical core debris beds over a wide range of parameters in order to determine the relative importance of conduction and convection in sodium-cooled debris beds. The bed has been simulated using directly heated two-dimensional packed tube bundles of different particle diameters, bed loadings, porosities, heat generation rates, and overlaying fluid layer heights. Detailed velocity and temperature profiles within the bed and overlaying fluid have been measured using particle tracing techniques and Mach-Zehnder interferometry. Measurements of the downward and upward power fractions and Nusselt numbers over a wide range of experimental variables have been made. The data have been compared with predictions of the transient three-dimensional natural convection computer code COMMIX-1A. 14 figures.

Date: October 1, 1982

Creator: Abdel-Khalik, S.I.

Object Type: Report

System: The UNT Digital Library

(open access)

Key Issues of FED/INTOR Impurity Control System

A key part of the FED/INTOR activity over the past year has focused on examining the critical issues and developing credible physics and engineering solutions for the impurity control system. The primary emphasis of the work was on the edge-region physics, plasma-wall interaction, materials, engineering and magnetic considerations of the poloidal divertor and pump limiter.

Date: October 1, 1982

Creator: Abdou, M. A.

Object Type: Article

System: The UNT Digital Library

(open access)

Tritium Breeding in Fusion Reactors

Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements.

Date: October 1, 1982

Creator: Abdou, M. A.

Object Type: Article

System: The UNT Digital Library

(open access)

Engineering testing requirements in FED/INTOR

The FED/INTOR critical issues activity has addressed three key testing requirements that have the largest impact on the design, operation and cost of FED/INTOR. These are: (1) the total testing time (fluence) during the device lifetime, (2) the minimum number of back-to-back cycles, and (3) the neutron wall load (power density in the first wall/blanket). The testing program activities were structured into three tasks in order to define the benefits, and in some cases, costs and risks of these testing requirements. The three tasks were carried out with wide participation of experts from a number of organizations in the United States. Similar effort was performed by Japan, the European Community and the Soviet Union.

Date: October 1, 1982

Creator: Abdou, M. A.; Nygren, R. E.; Morgan, G. D.; Trachsel, C. A.; Wire, G.; Oppermann, E. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Curvature-driven instabilities in the Elmo Bumpy Torus (EBT)

Curvature-driven instabilities are analyzed for an EBT configuration which consists of plasma interacting with a hot electron ring whose drift frequencies are larger than the growth rates predicted from conventional magnetohydrodynamic (MHD) theory. Stability criteria are obtained for five possible modes: the conventional hot electron interchange, a high-frequency hot electron interchange (at frequencies greater than the ion-cyclotron frequency), a compressional instability, a background plasma interchange, and an interacting pressure-driven interchange. A wide parameter regime for stable operation is found, which, however, severely deteriorates for a band of intermediate mode numbers. Finite Larmor radius effects can eliminate this deterioration; moreover, all short-wavelength curvature-driven modes are stabilized if the hot electron Larmor radius rho/sub h/ satisfies (kappa/sub perpendicular/rho/sub h/)/sup 2/ > 2..delta../(R..beta../sub h/(1 + P'/sub parallel//P'/sub perpendicular/)), where kappa/sub perpendicular/ is the transverse wavenumber, ..delta.. is the ring half-width, R is the mid-plane radius of curvature, ..beta../sub h/ is the hot electron beta value, and P' is the pressure gradient. Resonant wave-particle instabilities predicted by a new low frequency variational principle show that a variety of remnant instabilities may still persist.

Date: January 1, 1982

Creator: Abe, H.; Spong, D. A.; Antonsen, T. M. Jr.; Tsang, K. T. & Nguyen, K. T.

Object Type: Article

System: The UNT Digital Library

(open access)

Measurement of nu/sub e/ and anti nu/sub e/ elastic scattering as a test of the standard model

Various tests of standard SU(2) x U(1) model of weak interactions which can be performed by measurements of electron and muon neutrino-electron elastic scattering are reviewed. Electron neutrino-electron elastic scattering has both a neutral current part as well as a charged current part, and therefore offers a unique place to measure the interference of these two amplitudes. A measurement of the y-dependence of neutrino-electron elastic scattering can separately measure g/sub V/ and g/sub A/ as well as test for the presence of S, P, or T terms. Several measurable quantities involving cross sections and the interference term are derived from the standard model. Various design considerations for an experiment to determine the NC-CC interference term and the y-dependence of muon neutrino-electron elastic scattering are discussed.

Date: January 1, 1982

Creator: Abe, K.; Taylor, F.E. & White, D.H.

Object Type: Article

System: The UNT Digital Library

(open access)

Emanation of tritiated water from disposal sites at Los Alamos, New Mexico

The level of contamination induced by the presence of tritiated water (HTO) on the Bandelier tuff near Los Alamos, New Mexico has been seen to decrease vertically and horizontally at the same rate. This decrease in radioactivity with distance from the source has been measured around three different disposal shafts and found to be somewhat slower than the decrease in emanation rate with distance from the source. Physical factors, suspected of influencing HTO emanation, were entered as independent variables in a regression equation including measurements taken over a 14 month period. The physical variables studied were of thermal, hydrological, and meteorological origin or a combination of the above. Only four variables were retained as significant although they explained only 71% of the variation in the HTO flux.

Date: January 1, 1982

Creator: Abeele, W.V.

Object Type: Report

System: The UNT Digital Library

(open access)

Calculational limitations in PWR system simulation

Engineering transient analysis codes, which are in general more accurate than the present generation of simulator software, can be expected to yield reasonably accurate results (+-20% or so on system pressure) if carefully utilized and if the two-phase and transient flow conditions are not severe. As the severity of the transient increases, the confidence that one may have in the results decreases. None of the existing engineering analysis codes is well assessed or verified for transient analysis, but all give qualitatively the same results lending credence to their results. Recent comparisons to transients in LOFT and SEMISCALE are encouraging as are various comparisons to actual plant data.

Date: January 1, 1982

Creator: Abramson, P. B.; Kennedy, M. F. & Speis, T. P.

Object Type: Article

System: The UNT Digital Library

(open access)

Density and potential measurements in an intense ion-beam-generated plasma

Neutral beams are created by intense large area ion beams which are neutralized in a gas cell. The interaction of the beam with the gas cell creates a plasma. Such a plasma is studied here. The basic plasma parameters, electron temperature, density, and plasma potential, are measured as a function of beam current and neutral gas pressure. These measurements are compared to a model based on the solution of Poisson's equation. Because of the cylindrical geometry the equation cannot be solved analytically. Details of the numerical method are presented.

Date: May 1, 1982

Creator: Abt, N.E.

Object Type: Report

System: The UNT Digital Library

(open access)

Automatic test generation using a matrix model of digital systems

A matrix model for digital systems, formulated at the logic gate level, is used as a framework for automatic test generation. Tests are generated through a straightforward assignment procedure which follows the basic steps of path sensitization. The procedure, analogous in many ways to the D-algorithm, will always generate a test for stuck-at-1 and stuck-at-0 faults if such a test exists, and will identify faults for which no test can be derived.

Date: January 1, 1982

Creator: Acken, C. F.

Object Type: Article

System: The UNT Digital Library

(open access)

Study of technetium uptake in vegetation in the vicinity of the Portsmouth Gaseous Diffusion Plant

Technetium-99 was measured in vegetation and soil collected on and near the Portsmouth Gaseous Diffusion Plant to obtain an estimate of the soil-to-vegetation concentration factors. The concentration factors appear to be lognormally distributed with a geometric mean of 3.4 (Bq/kg dry wt. tissue per Bq/kg dry wt. soil) and a geometric standard deviation of 4.7. A dose commitment was calculated using a hypothetical 3.7 x 10/sup 10/ Bq Tc-99/year release and the actual CY-1981 concentration release of Tc-99. The radiological significance of Tc-99 in the terrestial food chain is substantially less than previously believed.

Date: January 1, 1982

Creator: Acox, T.A.

Object Type: Article

System: The UNT Digital Library

(open access)

Solubility in Binary Solvent Systems 1: Specific versus Nonspecific Interactions

Article on the solubility in binary solvent systems I and the specific versus nonspecific interactions.

Date: February 1, 1982

Creator: Acree, William E. (William Eugene) & Rytting, J. Howard

Object Type: Article

System: The UNT Digital Library

(open access)

Vapor-deposited /sup 235/UO/sub 2/ layers for an ultra-high-sensitivity fission counter

After evaluating the properties of uranium oxide coatings prepared by electrodeposition, painting and physical vapor deposition, the vapor deposition method was selected as being preferable for preparing coatings on aluminum electrodes having a total area of 5 m/sup 2/. The electrodes were used in an experimental fission chamber designed at the Oak Ridge National Laboratory for use as a neutron flux monitor the Clinch River Breeder Reactor. Initial testing of the Ultra-High Sensitivity Fission Counter (UHSFC) indicated that a tenfold increase in sensitivity was achieved as compared to commercially available fission counters. Techniques used in vapor coating and characterizing the /sup 235/UO/sub 2/ deposits on the large-area curved substrates are described.

Date: January 1, 1982

Creator: Adair, H. L.; Byrum, B. L.; Dailey, J. M. & Gibson, J. R.

Object Type: Article

System: The UNT Digital Library