1,288 Matching Results

Search Results

Results: 1 - 24 next
open access

The neutrinos in muon decay

Description: We review the available information on the identity of the neutrino states emitted in muon decay, and discuss the exotic decay {mu}{sup +} {yields} e{sup +} {bar {nu}}{sub e}{nu}{sub {mu}}. 22 refs.
Date: October 21, 1991
Creator: Herczeg, P.
Partner: UNT Libraries Government Documents Department
open access

High resolution x-ray crystal spectrographs

Description: Observation of x-ray line emissions are valuable for determining the thermodynamic state of the emitting plasma. For laser produced plasmas, diffraction crystals can be used to isolate x-ray monochromes to obtain high resolution spectral measurements. We will describe a versatile multi-crystal high resolution spectrograph used for photon energies from 0.5 to 6 keV. We will discuss a calculational package that tunes the response and sensitivity of the instrument and estimates the effect of sourc… more
Date: October 21, 1977
Creator: Koppel, L. N. & Eckels, J. D.
Partner: UNT Libraries Government Documents Department
open access

Numerical analysis of laminar forced convection in a spherical annulus

Description: Calculations of steady laminar incompressible fluid-flow and heat transfer in a spherical annulus are presented. Steady pressures, temperatures, velocities, and heat transfer coefficients are calculated for an insulated outer sphere and a 0/sup 0/C isothermal inner sphere with 50/sup 0/C heated water flowing in the annulus. The inner sphere radius is 13.97 cm, the outer sphere radius is 16.83 cm and the radius ratio is 1.2. The transient axisymmetric equations of heat, mass, and momentum conser… more
Date: July 21, 1980
Creator: Tuft, D.B.
Partner: UNT Libraries Government Documents Department
open access

On-site waste storage assuring the success of on-site, low-level nuclear waste storage

Description: Waste management has reached paramount importance in recent years. The successful management of radioactive waste is a key ingredient in the successful operation of any nuclear facility. This paper discusses the options available for on-site storage of low-level radioactive waste and those options that have been selected by the Department of Energy facilities operated by Martin Marietta Energy Systems, Inc. in Oak Ridge, Tennessee. The focus of the paper is on quality assurance (QA) features of… more
Date: September 21, 1986
Creator: Preston, E.L.
Partner: UNT Libraries Government Documents Department
open access

Limits on likesign dilepton production in nu/sub. mu. / interactions

Description: We have searched for the production of likesign dilepton events (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup -/ + ...) in a wideband neutrino beam at FNAL using the 15' bubble chamber. We observe no signal above the background arising from conventional sources. We set 90% confidence level upper limits for the production rates of (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup -/ + ...)/(nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + ...) less than or equal to 8 * 10/sup -5/ and (nu/sub ..… more
Date: May 21, 1985
Creator: Baker, N. J.; Connolly, P. L.; Kahn, S. A.; Murtagh, M. J.; Palmer, R. B.; Samios, N. P. et al.
Partner: UNT Libraries Government Documents Department
open access

The theory of hybrid stochastic algorithms

Description: These lectures introduce the family of Hybrid Stochastic Algorithms for performing Monte Carlo calculations in Quantum Field Theory. After explaining the basic concepts of Monte Carlo integration we discuss the properties of Markov processes and one particularly useful example of them: the Metropolis algorithm. Building upon this framework we consider the Hybrid and Langevin algorithms from the viewpoint that they are approximate versions of the Hybrid Monte Carlo method; and thus we are led to… more
Date: November 21, 1989
Creator: Kennedy, A.D. (Florida State Univ., Tallahassee, FL (USA). Supercomputer Computations Research Inst.)
Partner: UNT Libraries Government Documents Department
open access

Elimination of electromagnetic radiation in plasma simulation: the Darwin or magnetoinductive approximation

Description: For many astrophysical and most magnetic fusion applications, the purely electromagnetic modes generated by real as well as simulation ''plasma'' fluctuations are a source of high frequency radiation that is often irrelevant to the physics of interest. Unfortunately, a numerical CFL stability limit prevents either making c infinite or deltat large while using the usual explicit Maxwell's equations for the fields. A modification of Maxwell's equations, which provides implicitly the field compone… more
Date: February 21, 1985
Creator: Hewett, D.W.
Partner: UNT Libraries Government Documents Department
open access

Experimental determination of lower plenum ECC injection effectiveness

Description: The effectiveness of lower plenum emergency core coolant (ECC) injection during a double ended offset shear cold leg break loss-of-coolant accident (LOCA) was investigated experimentally in a small-scale model of a pressurized water reactor (PWR). In order to determine relative merit of the lower plenum injection concept to mitigate the severity of a large break LOCA, data from lower plenum injection experiments were compared to data from an experiment in the Semiscale Mod-3 sytem in which cold… more
Date: November 21, 1980
Creator: Hanson, R.G.
Partner: UNT Libraries Government Documents Department
open access

Surface treatment of lead glass microsphere

Description: The structural arrangement of a hydrated glass surface depends on the composition, thermal history and surface treatment. This paper considers the surface treatment of a lead glass with weak and strong acid solutions and in particular hydrogen peroxide, to give a microscopically clean microsphere.
Date: May 21, 1980
Creator: Andrews, J.E. Jr. & Koo, J.C.
Partner: UNT Libraries Government Documents Department
open access

2660 A holographic interferometry of laser produced plasmas from tilted disk targets

Description: Using double exposure holographic interferometry, an investigation has been made of the Nd laser produced plasmas surrounding disk targets irradiated at different angles of incidence. Measurements have produced a detailed description of the plasma profile necessary for realistic simulations of resonance absorption. A 2660A 15 psec probe pulse is produced by frequency quadrupling a fraction of the main Nd laser pulse from the Janus laser. F/1 and f/10 lenses were utilized to irradiate the target… more
Date: October 21, 1977
Creator: Auerbach, J.M.; Attwood, D.T.; Lee, P.H.Y. & Sweeney, D.W.
Partner: UNT Libraries Government Documents Department
open access

Qualification of tribological materials and coatings for use in sodium. [LMFBR]

Description: This paper describes some of the essential performance measures used to qualify materials for tribological applications in liquid sodium environments and summarizes relative properties of some of the newer tribological materials now qualified for use in sodium systems.
Date: April 21, 1980
Creator: Johnson, R. N. & Farwick, D. G.
Partner: UNT Libraries Government Documents Department
open access

Fundamental study of crack initiation and propagation. [Computer model of ductile fracture]

Description: Objective is to determine the fracture toughness of A533B-1 steel by computer modeling Charpy V-notch tests. A computer model of ductile fracture was developed that predicts fracture initiation. The model contains a set of material-dependent parameters obtained by computer simulations of small specimen tests. The computer calculations give detailed stress and strain histories up to the time of fracture, which are used to determine the model parameter values. The calibrated fracture model, that … more
Date: December 21, 1977
Creator: Norris, D.M. Jr.; Reaugh, J.E.; Moran, B.; Quinones, D.F. & Wilkins, M.L.
Partner: UNT Libraries Government Documents Department
open access

Absolute instrumental neutron activation analysis at Lawrence Livermore Laboratory

Description: The Environmental Science Division at Lawrence Livermore Laboratory has in use a system of absolute Instrumental Neutron Activation Analysis (INAA). Basically, absolute INAA is dependent upon the absolute measurement of the disintegration rates of the nuclides produced by neutron capture. From such disintegration rate data, the amount of the target element present in the irradiated sample is calculated by dividing the observed disintegration rate for each nuclide by the expected value for the d… more
Date: December 21, 1977
Creator: Heft, R.E.
Partner: UNT Libraries Government Documents Department
open access

Sub-keV, subnanosecond measurements of x-ray spectra from laser-produced plasmas

Description: As part of the effort to extend our x-ray diagnostic capabilities, we have made x-ray spectral measurements of laser-produced plasmas for photon energies down to 100 eV with a time response of 0.5 nsec. Fast, windowless x-ray diodes were used in conjunction with critical angle reflecting mirrors and thin filters for energy definition for two channels, 300 to 600 eV and 800 to 1300 eV. A third channel, using only an x-ray diode and filter, provided spectral information in the 100 to 300 eV regio… more
Date: October 21, 1977
Creator: Kornblum, H. N.; Koppel, L. N.; Slivinsky, V. W.; Glaros, S. S.; Ahlstrom, H. G. & Larsen, J. T.
Partner: UNT Libraries Government Documents Department
open access

Automatic x-ray image analysis and sorting of laser fusion targets

Description: A microcomputer-based x-ray image analysis system to select and measure laser fusion targets is described. This system positions a photographic plate in x and y, focuses a microscope image, digitizes and extracts measurements within seconds.
Date: August 21, 1979
Creator: Singleton, R.M. & Perkins, D.E.
Partner: UNT Libraries Government Documents Department
open access

Reggeon Field Theory and the phases of QCD

Description: We propose a Reggeon Field Theory phase diagram involving Sub-critical and Super-critical Pomeron behavior and the Expanding Disc. We describe the derivation of Reggeon Field Theory from QCD using infra-red analysis of the reggeon diagrams of the spontaneously broken theory. Matching the Reggeon Field Theory phase-diagram to that of lattice QCD with many fermions has significant implications for the chiral properties of continuum QCD when the number of flavors is less than the maximum allowed b… more
Date: July 21, 1987
Creator: White, A.R.
Partner: UNT Libraries Government Documents Department
open access

Filtered detector arrays for single pulsed photon measurements above 100 keV

Description: We discuss the design of filtered detector arrays for single pulsed, 100 keV photon spectral and angular distribution measurements at the Lawrence Livermore Laboratory Argus laser facility.
Date: October 21, 1977
Creator: Tirsell, K.G. & Catron, H.C.
Partner: UNT Libraries Government Documents Department
open access

Single-column-based absorption process for treating dissolver off-gas

Description: The fluorocarbon absorption process for krypton and xenon removal from dissolver off-gas is based on exploitation of solubility differences which exist among noble gases and other gas-phase constituents in the fluorocarbon solvent dichlorofluoromethane (refrigerant-12). Process performance and reliability have been demonstrated on an engineering scale with over 10 years of pilot plant operation, including testing with /sup 85/Kr, /sup 133/Xe, and /sup 131/I. The culmination of this work is a si… more
Date: May 21, 1982
Creator: Eby, R. S.; Little, D. K.; Merriman, J. R. & Stephenson, M. J.
Partner: UNT Libraries Government Documents Department
open access

Plasma production and flow in negative ion beams

Description: Plasma generated in low-density vapor by a negative ion beam has been studied experimentally and computationally. We show that space charge neutralization of the beam occurs at very low vapor density, and that correspondingly the electron density may be much less than the beam and plasma ion densities. When there is a large local gas density, as in a charge changing cell, the resulting high electron density is also localized to the same region. Therefore, very few electrons will reach a negativ… more
Date: September 21, 1977
Creator: Anderson, O. A. & Hooper, E. B. Jr.
Partner: UNT Libraries Government Documents Department
open access

Determination of somatic mutations in human erythrocytes by cytometry

Description: Flow cytometric assays of human erythrocytes labeled with monoclonal antibodies specific for glycophorin A were used to enumerate variant cells that appear in peripheral blood as a result of somatic gene-loss mutations in erythrocyte precursor cells. The assay was performed on erythrocytes from 10 oncology patients who had received at least one treatment from radiation or mutagenic chemotherapy at least 3 weeks before being assayed. The patients were suffering from many different malignancies (… more
Date: June 21, 1985
Creator: Jensen, R.H.; Langlois, R.G. & Bigbee, W.L.
Partner: UNT Libraries Government Documents Department
open access

Relaxation of neodymium in a weakly ionized expanding plasma

Description: The laser resonance absorption technique has been used to determine the relaxation rate of electronically excited neodymium vapor during its expansion into vacuum. Significant increases of population into ground and 1128 cm/sup -1/ levels were found. Analysis shows that interaction between excited metastable atoms and electrons are much more important for relaxation than atom-atom collisions. The final population of neodymium appears to be frozen at a temperature lower than the surface temperat… more
Date: June 21, 1977
Creator: Chen, H. L.; Bedford, R.; Borzileri, C.; Brunner, W. & Hayes, M.
Partner: UNT Libraries Government Documents Department
open access

Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years

Description: Because changes in solar activity can modify the fluxes of cosmic-ray particles in the solar system, the nature of the galactic and solar cosmic rays and their interactions with matter are described and used to study the ancient sun. The use of cosmogenic nuclides in meteorites and lunar samples as detectors of past cosmic-ray variations are discussed. Meteorite records of the history of the galactic cosmic rays are reviewed. The fluxes of solar protons over various time periods as determined f… more
Date: March 21, 1980
Creator: Reedy, R. C.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen