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The neutrinos in muon decay (open access)

The neutrinos in muon decay

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.
System: The UNT Digital Library
High resolution x-ray crystal spectrographs (open access)

High resolution x-ray crystal spectrographs

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 source extent on spectral resolution. A scheme using fine slits to obtain spatial resolution with the basic instrument will also be described. An instrument is being built for Shiva diagnostics that incorporates a diffraction crystal and an x-ray streak camera. The design rationale for the crystal stage will be discussed.
Date: October 21, 1977
Creator: Koppel, L. N. & Eckels, J. D.
System: The UNT Digital Library
Numerical analysis of laminar forced convection in a spherical annulus (open access)

Numerical analysis of laminar forced convection in a spherical annulus

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 conservation are solved numerically in spherical coordinates. The transient solution is carried out in time until steady state is achieved. A variable mesh is used to improve resolution near the inner sphere where temperature and velocity gradients are steep. It is believed that this is the first fully two-dimensional analysis of forced flow in a spherical annulus. Local and bulk Nusselt numbers are presented for Reynolds numbers from 4.4 to 440. Computed bulk Nusselt numbers ranged from 2 to 50 and are compared to experimental results from the literature. Inlet flow jetting off the inner sphere and flow separation are predicted by the analysis. The location of wall jet separation was found to be a function of Reynolds number, indicating the location of separation depends …
Date: July 21, 1980
Creator: Tuft, D.B.
System: The UNT Digital Library
On-site waste storage assuring the success of on-site, low-level nuclear waste storage (open access)

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

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 waste management activities such as accountability and retrievability of waste materials and waste packages, retrievability of data, waste containment, safety and environmental monitoring. Technical performance and careful documentation of that performance are goals which can be achieved only through the cooperation of numerous individuals from waste generating and waste managing organizations, engineering, QA, and environmental management.
Date: September 21, 1986
Creator: Preston, E.L.
System: The UNT Digital Library
Limits on likesign dilepton production in nu/sub. mu. / interactions (open access)

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

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 ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup -/ + ...)/(nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup +/ + ...) less than or equal to 6 * 10/sup -2/.
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.
System: The UNT Digital Library
The theory of hybrid stochastic algorithms (open access)

The theory of hybrid stochastic algorithms

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 consider Molecular Dynamics using the Leapfrog algorithm. The lectures conclude by reviewing recent progress in these areas, explaining higher-order integration schemes, the asymptotic large-volume behaviour of the various algorithms, and some simple exact results obtained by applying them to free field theory. It is attempted throughout to give simple yet correct proofs of the various results encountered. 38 refs.
Date: November 21, 1989
Creator: Kennedy, A.D. (Florida State Univ., Tallahassee, FL (USA). Supercomputer Computations Research Inst.)
System: The UNT Digital Library
Elimination of electromagnetic radiation in plasma simulation: the Darwin or magnetoinductive approximation (open access)

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

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 components, circumvents this problem. The solution is to neglect retardation effects so that the electromagnetic propagation speed is effectively infinite. The purely electromagnetic modes in this limit evolve ''instantly'' to a time-asymptotic configuration about the macroscopic plasma configuration at each new time level. The Darwin or magnetoinductive approximation effectively provides infinite propagation speeds for purely electromagnetic modes by converting Maxwell's equations from hyperbolic to elliptic in character. In practice, this is accomplished by neglecting the solenoidal part of the displacement current. The elimination of the CFL time step constraint more than offsets the substantially more complicated field solution that is required. The details of a numerical implementation of this model will be presented. Numerical examples will be given and extentions of the Darwin field solution to other plasma models …
Date: February 21, 1985
Creator: Hewett, D.W.
System: The UNT Digital Library
Experimental determination of lower plenum ECC injection effectiveness (open access)

Experimental determination of lower plenum ECC injection effectiveness

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 leg ECC injection was utilized. The results indicated that lower plenum injection was extremely effective in initiating early reflooding of the core and earlier rod quenching than was observed in the cold leg injection experiment.
Date: November 21, 1980
Creator: Hanson, R.G.
System: The UNT Digital Library
Surface treatment of lead glass microsphere (open access)

Surface treatment of lead glass microsphere

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.
System: The UNT Digital Library
2660 A holographic interferometry of laser produced plasmas from tilted disk targets (open access)

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

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 targets with intensities ranging from 10/sup 13/ w/cm/sup 2/ to 10/sup 16/ w/cm/sup 2/. Measurements have produced the shape of the electron density profile near critical, the direction of the plasma blowoff, and revealed transverse rippling of the isodensity surfaces.
Date: October 21, 1977
Creator: Auerbach, J.M.; Attwood, D.T.; Lee, P.H.Y. & Sweeney, D.W.
System: The UNT Digital Library
Qualification of tribological materials and coatings for use in sodium. [LMFBR] (open access)

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

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.
System: The UNT Digital Library
Fundamental study of crack initiation and propagation. [Computer model of ductile fracture] (open access)

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

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 correctly predicts fracture initiation (and initiation energy) in the Charpy specimen, may then be used to simulate tests of accepted fracture-toughness specimens and hence obtain fracture toughness. The model parameters were calibrated to predict fracture in four different test specimens: two different notched-tension specimens, a simple tension specimen, and a precracked compact-tension specimen. The model was then used in a computer simulation of the Charpy V-notch specimen to initiate and advance a flat fracture. Results were compared with interrupted Charpy tests. Calibration of the model for two additional heat treatments of A533B-1 steel is in progress.
Date: December 21, 1977
Creator: Norris, D.M. Jr.; Reaugh, J.E.; Moran, B.; Quinones, D.F. & Wilkins, M.L.
System: The UNT Digital Library
Absolute instrumental neutron activation analysis at Lawrence Livermore Laboratory (open access)

Absolute instrumental neutron activation analysis at Lawrence Livermore Laboratory

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 disintegration rate per microgram of the target element that produced the nuclide. In absolute INAA, the expected value for disintegration rate per microgram is calculated from nuclear parameters and from measured values of both thermal and epithermal neutron fluxes which were present during irradiation. Absolute INAA does not depend on the concurrent irradiation of elemental standards but does depend on the values for thermal and epithermal neutron capture cross-sections for the target nuclides. A description of the analytical method is presented.
Date: December 21, 1977
Creator: Heft, R.E.
System: The UNT Digital Library
Sub-keV, subnanosecond measurements of x-ray spectra from laser-produced plasmas (open access)

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

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 region. Results from exploding pusher targets will be presented and compared with those of other diagnostic techniques and Lasnex calculations. Future expansion and modifications of the present system will be discussed.
Date: October 21, 1977
Creator: Kornblum, H. N.; Koppel, L. N.; Slivinsky, V. W.; Glaros, S. S.; Ahlstrom, H. G. & Larsen, J. T.
System: The UNT Digital Library
Symmetry-induced intermittency in a stochastic reflexive model (open access)

Symmetry-induced intermittency in a stochastic reflexive model

Article on symmetry-induced intermittency in a stochastic reflexive model.
Date: February 21, 2012
Creator: Palatella, Luigi & Grigolini, Paolo
System: The UNT Digital Library
First-principles theory of metal-alkaline earth oxide interfaces (open access)

First-principles theory of metal-alkaline earth oxide interfaces

Article on the first-principles theory of metal-alkaline earth oxide interfaces.
Date: June 21, 2006
Creator: Nuñez, Matías & Buongiorno Nardelli, Marco
System: The UNT Digital Library
Automatic x-ray image analysis and sorting of laser fusion targets (open access)

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

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.
System: The UNT Digital Library
Reggeon Field Theory and the phases of QCD (open access)

Reggeon Field Theory and the phases of QCD

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 by asymptotic freedom. 19 refs., 7 figs.
Date: July 21, 1987
Creator: White, A.R.
System: The UNT Digital Library
Filtered detector arrays for single pulsed photon measurements above 100 keV (open access)

Filtered detector arrays for single pulsed photon measurements above 100 keV

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.
System: The UNT Digital Library
Single-column-based absorption process for treating dissolver off-gas (open access)

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

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 single-column design which results in a simplified process with improved reliability and lower cost. Data are presented summarizing recent single-column development activities. These include data plots depicting decontamination factor vs feed gas flow rate, DF vs process absorption factor (kG/L), and location of the concentration peak via the solvent flow rate. In general, 99% removal is easily obtainable for Kr, Xe, and CO/sub 2/ while attaining concentration factors on the order of 10/sup 3/ to 10/sup 4/. Further concentration of the Kr product is investigated using solid sorbent and cold trapping technologies. Effective removal of entrained fluorocarbon solvent and CO/sub 2/ from the single-column product stream is demonstrated using 13X and 5A molecular sieves, respectively. Additional separation of Xe is studied using a silver mordenite bed and compared to existing …
Date: May 21, 1982
Creator: Eby, R. S.; Little, D. K.; Merriman, J. R. & Stephenson, M. J.
System: The UNT Digital Library
Plasma production and flow in negative ion beams (open access)

Plasma production and flow in negative ion beams

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 negative ion accelerator even if it is placed one or two beam diameters from such a cell.
Date: September 21, 1977
Creator: Anderson, O. A. & Hooper, E. B. Jr.
System: The UNT Digital Library
Determination of somatic mutations in human erythrocytes by cytometry (open access)

Determination of somatic mutations in human erythrocytes by cytometry

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 (e.g., breast, renal, bone, colon and lung), and were treated with several different mutagenic therapeutics (e.g., cisplatinum, adriamycin, daunomycin, or cyclophosphamide). The frequency of these variant cells is an indication of the amount of mutagenic damage accumulated in the individual's erythropoietic cell population. Comparing these results to HPRT clonogenic assays, we find similar baseline frequencies of somatic mutation as well as similar correlation with mutagenic exposures. 9 refs., 3 figs., 1 tab.
Date: June 21, 1985
Creator: Jensen, R.H.; Langlois, R.G. & Bigbee, W.L.
System: The UNT Digital Library
Relaxation of neodymium in a weakly ionized expanding plasma (open access)

Relaxation of neodymium in a weakly ionized expanding plasma

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 temperature of melt.
Date: June 21, 1977
Creator: Chen, H. L.; Bedford, R.; Borzileri, C.; Brunner, W. & Hayes, M.
System: The UNT Digital Library
Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years (open access)

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

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 from lunar radionuclide data are presented and examined. The intensities of solar protons emitted during 1954 to 1964 (11-year solar cycle number 19) were much larger than those for 1965 to 1975 (solar cycle 20). Average solar-proton fluxes determined for the last one to ten million years from lunar /sup 26/Al and /sup 53/Mn data show little variation and are similar to the fluxes for recent solar cycles. Lunar activities of /sup 14/C (and preliminary results for /sup 81/Kr) indicate that the average fluxes of solar protons over the last 10/sup 4/ (and 10/sup 5/) years are several times larger than those for the last 10/sup 6/ to 10/sup 7/ years; however, cross-section measurements and other work are needed to …
Date: March 21, 1980
Creator: Reedy, R. C.
System: The UNT Digital Library