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V sup 0 Production with 14. 5 GeV/c Silicon Beams (open access)

V sup 0 Production with 14. 5 GeV/c Silicon Beams

This talk deals with {Lambda}, K{sub s}{sup 0} and {bar {Lambda}} production with 14.5 GeV/c Silicon beams. Why study {Lambda}{sup 0} production Because the study of strangeness is an important part of the search for Quark Gluon Plasma (QGP). Many models predict an enhancement of strangeness in a QGP as compared to the amount of strangeness produced in a superposition of nucleon-nucleon interactions. The amount of enhancement varies from model to model. Even if no QGP is detected at AGS energies using Si beams, it is important to understand the production mechanisms in quantitative detail so that standard nucleon-nucleon production mechanism can be distinguished from QGP formation. The advantage of measuring strangeness production by measuring V{sup 0} production is that V{sup 0}'s can be identified by kinematics without the use of any special particle ID detectors. The disadvantage is that usually large aperture detectors are required. Experiment 810 has the needed large aperture. This talk describes the technique and results of V{sup 0} production from {approximately}9000 interactions of Si in a 1 mil (25 micron) Au target recorded in June 1989. 13 figs., 1 tab.
Date: March 26, 1990
Creator: Bonner, B. E.; Buchanan, J. A.; Chiou, C. N.; Clement, J. M.; Corcoran, M. D.; Kruk, J. W. et al.
System: The UNT Digital Library
Some ongoing research in the U. S. that relates to nuclear reactor pressure components (open access)

Some ongoing research in the U. S. that relates to nuclear reactor pressure components

The presentation of US research programs at the last IWG-RRPC meeting emphasized several aspects of the work sponsored by the Nuclear Regulatory Commission (NRC). The remarks given this year will focus on work that relates to pressurized water reactor primary pressure vessels. While most of the comments are relative to NRC work, some are included relative to the Electric Power Research Institute (EPRI) and the Department of Energy. Additionally, a forthcoming CSNI workshop on fracture methodology validation will be described. 36 figs.
Date: March 1, 1990
Creator: Pugh, C. E.
System: The UNT Digital Library
An interactive beam position monitor system simulator (open access)

An interactive beam position monitor system simulator

A system simulator has been implemented to aid the development of the RHIC position monitor system. Based on the LabVIEW software package by National Instruments, this simulator allows engineers and technicians to interactively explore the parameter space of a system during the design phase. Adjustable parameters are divided into three categories: beam, pickup, and electronics. The simulator uses these parameters in simple formulas to produce results in both time-domain and frequencydomain. During the prototyping phase, these simulated results can be compared to test data acquired with the same software package. The RHIC position monitor system is presented as an example, but the software is applicable to several other systems as well.
Date: March 1, 1993
Creator: Ryan, W. A. & Shea, T. J.
System: The UNT Digital Library
epsilon. prime /. epsilon. and heavy top (open access)

epsilon. prime /. epsilon. and heavy top

The article reviews the new theoretical developments for the CP-parameter {epsilon}{prime}/{epsilon} and its intimate connection with the mass of a heavy top quark. 22 refs., 8 figs., 1 tab.
Date: March 1, 1990
Creator: Paschos, E. A. (Fermi National Accelerator Lab., Batavia, IL (USA)); Schneider, T. (Dortmund Univ. (Germany, F. R.). Inst. fuer Physik) & Wu, Y. L. (Mainz Univ. (Germany, F. R.). Inst. fuer Physik)
System: The UNT Digital Library
Correlation of the Na/K Ratio in Geothermal Well Waters With the Thermodynamic Properties of Low Albite and Potash Feldspar (open access)

Correlation of the Na/K Ratio in Geothermal Well Waters With the Thermodynamic Properties of Low Albite and Potash Feldspar

The Na/K ratio in geothermal well waters provides a better estimate of the relative stability of low albite and potash feldspar than do predictions from calorimetry and high temperature phase equilibria. The calculated saturation indices from field data for low albite, potash feldspar suggest that [Delta]G[sub f,298][sup o] for the latter should be revised to [minus]3748.6[plus minus]3.7 kJ.mol[sup [minus]1].
Date: March 1, 1992
Creator: Apps, J. A. & Chang, G. M.
System: The UNT Digital Library
Energy deposition and radiation shielding in the Pbar source at Fermilab (open access)

Energy deposition and radiation shielding in the Pbar source at Fermilab

This report discusses the antiproton source beamline elements and the energy deposition and radiation shielding for a antiproton source. (LSP).
Date: March 1, 1992
Creator: Bhat, C.
System: The UNT Digital Library
Minimal dynamical symmetry breaking of the electroweak interactions and m sub top (open access)

Minimal dynamical symmetry breaking of the electroweak interactions and m sub top

We review the recent idea of a mechanism for breaking the electroweak interactions which relies upon the formation of condensates involving the conventional quarks and leptons. In particular, such a scheme would indicate that the top quark is heavy, greater than or of order 200 GeV, and gives further predictions for the Higgs boson mass. It may be imbedded either into a GUT setting using supersymmetry or applied to a fourth generation with new strong TEV scale flavor-interactions. 13 refs., 2 tabs.
Date: March 1, 1990
Creator: Hill, C. T.
System: The UNT Digital Library
Simulation of vortex-line pinning by defects in the Y-Ba-Cu-O system (open access)

Simulation of vortex-line pinning by defects in the Y-Ba-Cu-O system

The temperature properties of a two-dimensional flux lattice are studied by Monte Carlo simulation, with particular attention to the effects of twin-boundaries. The parameters selected are appropriate for the YBa{sub 2}CU{sub 3}0{sub 7} high-temperature superconducting system. The intrinsic properties of the vortex state are investigated by monitoring system evolution at fixed temperature and applied magnetic field. By varying the temperature, the loss of type-II superconductivity via fluxoid lattice melting is also examined. The introduction of model defects induces the creation of metastable and glassy states which reduce overall hexane order but are found to enhance system resistance to flux-lattice melting.
Date: March 1, 1992
Creator: Jamison, R.; Burmester, C. P.; Gronsky, R. & Wille, L. T.
System: The UNT Digital Library
Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee (open access)

Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Emergency preparedness for industry was commonly believed to be an essential responsibility on the part of management. Therefore, this study was conducted to research and accumulate information and data on emergency preparedness at Oak Ridge National Laboratory (ORNL). The objective of this study was to conduct a thorough evaluation of emergency preparedness knowledge among employees to determine if they were properly informed or if they needed more training. Also, this study was conducted to provide insight to management as to what their responsibility was concerning this training. To assess employee emergency preparedness knowledge, a questionnaire was developed and administered to 100 employees at ORNL. The data was analyzed using frequencies and percentages of response and was displayed through the use of graphs within the report. 22 refs., 22 figs.
Date: March 1, 1990
Creator: Skipper, M. N.
System: The UNT Digital Library
Isotopic tailoring with sup 59 Ni to study the effect of helium on microstructural evolution and mechanical properties of neutron-irradiated Fe-Cr-Ni alloys (open access)

Isotopic tailoring with sup 59 Ni to study the effect of helium on microstructural evolution and mechanical properties of neutron-irradiated Fe-Cr-Ni alloys

Tensile testing on three model Fe-Cr-Ni alloys removed from four discharges of the {sub 59}Ni isotopic doping experiment in FFTF-MOTA indicates that helium/dpa ratios typical of fusion reactors do not produce changes in the yield strength or elongation that are significantly different from those at much lower helium generation rates. It also appears that tensile properties approach a saturation level that is dependent only on the final irradiation temperature, but not prior temperature history or thermomechanical starting condition. The saturation in mechanical properties reflects a similar saturation in microstructure that is independent of starting condition. The successful conduct of an isotopic doping experiment was found to require post-irradiation measurement of the helium levels in order to compensate for uncertainties in the cross sections for burn-out and burn-in of {sub 59}Ni and for uncertainties in neutron flux and spectra in the vicinity of the edge of the core.
Date: March 1, 1992
Creator: Garner, F. A.; Hamilton, M. L.; Greenwood, L. R. (Pacific Northwest Lab., Richland, WA (United States)); Stubbins, J. F. (Illinois Univ., Urbana, IL (United States)) & Oliver, B. M. (Rockwell International Corp., Canoga Park, CA (United States))
System: The UNT Digital Library
Seventh BES (Basic Energy Sciences) catalysis and surface chemistry research conference (open access)

Seventh BES (Basic Energy Sciences) catalysis and surface chemistry research conference

Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases. (CBS)
Date: March 1, 1990
Creator: unknown
System: The UNT Digital Library
Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O (open access)

Submillimeter and microwave residual losses in epitaxial films of Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O

We have used a novel bolometric technique and a resonant technique to obtain accurate submillimeter and microwave residual loss data for epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7}, Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10} and Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8}. For all films we obtain good agreement between the submillimeter and microwave data, with the residual losses in both the Y-Ba-Cu-O and Tl-Ca-Ba-Cu-O films scaling approximately as frequency squared below {approximately} 1 THz. We are able to fit the losses in the Y-Ba-Cu-O films to a weakly coupled grain model for the a-b plane conductivity, in good agreement with results from a Kramers-Kronig analysis of the loss data. We observe strong phonon structure in the Tl-Ca-Ba-Cu-O films for frequencies between 2 and 21 THz, and are unable to fit these losses to the simple weakly coupled grain model. This is in strong contrast to the case for other high {Tc} superconductors such as YBa{sub 2}Cu{sub 3}O{sub 7}, where phonon structure observed in ceramic samples is absent in epitaxial oriented films and crystals because of the electronic screening due to the high conductivity of the a-b planes.
Date: March 1, 1992
Creator: Miller, D.; Richards, P. L.; Garrison, S. M.; Newman, N.; Eom, C. B.; Geballe, T. H. et al.
System: The UNT Digital Library
Dynamic effect of sodium-water reaction in fast flux test facility power addition sodium pipes (open access)

Dynamic effect of sodium-water reaction in fast flux test facility power addition sodium pipes

The Fast Flux Facility (FFTF) is a demonstration and test facility of the sodium-cooled fast breeder reactor. A power addition'' to the facility is being considered to convert some of the dumped, unused heat into electricity generation. Components and piping systems to be added are sodium-water steam generators, sodium loop extensions from existing dump heat exchangers to sodium-water steam generators, and conventional water/steam loops. The sodium loops can be subjected to the dynamic loadings of pressure pulses that are caused by postulated sodium leaks and subsequent sodium-water reaction in the steam generator. The existing FFTF secondary pipes and the new power addition sodium loops were evaluated for exposure to the dynamic effect of the sodium-water reaction. Elastic and simplified inelastic dynamic analyses were used in this feasibility study. The results indicate that both the maximum strain and strain range are within the allowable limits. Several cycles of the sodium-water reaction can be sustained by the sodium pipes that are supported by ordinary pipe supports and seismic restraints. Expensive axial pipe restraints to withstand the sodium-water reaction loads are not needed, because the pressure-pulse-induced alternating bending stresses act as secondary stresses and the pressure pulse dynamic effect is a deformation-controlled quantity …
Date: March 1, 1990
Creator: Huang, S. N. & Anderson, M. J.
System: The UNT Digital Library
A proposed IR quad for the SSC (open access)

A proposed IR quad for the SSC

This note outlines a detailed magnetic design of a high-gradient quadrupole for the beam interaction region of the SSC. The 58 mm bore, 2 layer magnet uses 36 strand cable identical to the collider dipole magnet outer cable, thin collars, a close-fitting iron yoke, and a shell for structural support. With a 1.3:1 Cu/Sc ratio the quadrupole short sample gradient is 274 T/m at 1.9K and 209.7 T/m at 4.35 K with good field quality. Assembled with 7mm collars, the magnet is placed inside a four-segment iron yoke and prestressed with welded outer shell. Prestress is maintained during cooldown by aluminum spacers placed between the segmented iron yoke blocks. This paper describes various conceptual design details including coil geometry, load line and margin, field uniformity and saturation effects.
Date: March 1, 1992
Creator: Caspi, S.; Taylor, C. & Wandesforde, A.
System: The UNT Digital Library
Determination of the strain field from an HREM image of a Si Lomer dislocation. [High-resolution electron microscopy (HREM)] (open access)

Determination of the strain field from an HREM image of a Si Lomer dislocation. [High-resolution electron microscopy (HREM)]

A new approach to quantitative deformation characterization of high-resolution electron microscopy (HREM) defect images has been developed. The principle of this technique, (Computational Fourier Transform Deformation (CFTD)) is to extract an accurate displacement field about a defect from its HREM image using Fourier transformation procedures. The methodology's unique feature is to digitize the defect image and compute the Moire pattern, from which the displacement field is obtained, without the need for an external reference lattice image, normally associated with the interference phenomena. From this data, the displacement gradient can be calculated, which yields much information on the experimental deformation mechanics. One question that has arisen is whether different imaging conditions of the same defect affects the results of the CFM analysis. We have studied this problem by analyzing the strain components of simulated images of a Lomer dislocation in Si and present our findings here.
Date: March 1, 1992
Creator: Tsai, K. H.; Schwartzman, A. F.; Gallego, R.; Ortiz, M.; Kim, K. S. (Brown Univ., Providence, RI (United States). Div. of Engineering) & O'Keefe, M. A. (Lawrence Berkeley Lab., CA (United States))
System: The UNT Digital Library
US-Japan workshop on atomic collisions in solids: Abstracts of lectures (open access)

US-Japan workshop on atomic collisions in solids: Abstracts of lectures

This report contains abstracts on the following topics: techniques of scanning probe microscopy; new types of radiation; a search for wake-riding electrons using slow antiproton beams; antiproton wake: theory; bending of swift ion beams by graphite foils; angular momentum distribution of autoionizing rydberg states: produced by 64 MeV S ions in collisions with C foils; multiphonon energy exchange in atom-surface collisions; plans for positron experiments; resonant coherent excitation: experiment; line shapes in resonant coherent excitation: theory; MUSE experiments and Monte Carlo simulation; inelastic interactions of electrons and positrons with solids; density fluctuation detection; cluster-impact fusion; a model for cluster-impact fusion; thoughts on cold fusion; and plasmon decay.
Date: March 1, 1990
Creator: unknown
System: The UNT Digital Library
Proceedings of a Symposium on the Occasion of the 40th Anniversary of the Nuclear Shell Model (open access)

Proceedings of a Symposium on the Occasion of the 40th Anniversary of the Nuclear Shell Model

This report contains papers on the following topics: excitation of 1p-1h stretched states with the (p,n) reaction as a test of shell-model calculations; on Z=64 shell closure and some high spin states of {sup 149}Gd and {sup 159}Ho; saturating interactions in {sup 4}He with density dependence; are short-range correlations visible in very large-basis shell-model calculations ; recent and future applications of the shell model in the continuum; shell model truncation schemes for rotational nuclei; the particle-hole interaction and high-spin states near A-16; magnetic moment of doubly closed shell +1 nucleon nucleus {sup 41}Sc(I{sup {pi}}=7/2{sup {minus}}); the new magic nucleus {sup 96}Zr; comparing several boson mappings with the shell model; high spin band structures in {sup 165}Lu; optical potential with two-nucleon correlations; generalized valley approximation applied to a schematic model of the monopole excitation; pair approximation in the nuclear shell model; and many-particle, many-hole deformed states.
Date: March 1, 1990
Creator: Lee, T. S. H. & Wiringa, R. B.
System: The UNT Digital Library
Premixed turbulent combustion to opposed streams (open access)

Premixed turbulent combustion to opposed streams

Premixed turbulent combustion in opposed streams has been studied experimentally by the use of two component laser doppler aneomometry. This flow geometry is part of a class of stagnating flows used to study turbulent combustion in recent years. It does not involve any surface near the flames because of the flow symmetry thus circumventing many of the effects of flame surface interaction. The mean non-reacting flow is found to be self-similar for all the conditions studied in this and the stagnation plate configuration. A homogeneous region of plane straining is produced in the vicinity of the stagnation and there is a strong interaction between the turbulence in the flow and the mean straining which can increase the rms velocity as the flow stagnates. The reacting flow fields are found to be symmetric about the free stagnation point. The traverses of mean axial velocity in the stagnation streamlines for reaction flows are not dramatically different from the non-reaction flows. These results differ from turbulent combustion experiments where the flow is stagnated by a flat plate. The extinction limits was studied for propane:air mixtures. 11 refs.
Date: March 1, 1992
Creator: Kostiuk, L. W. & Cheng, R. K.
System: The UNT Digital Library
Ideas for future synchrotron light sources (open access)

Ideas for future synchrotron light sources

Synchrotron light sources have advanced in the past two-to-three decades through three generations,'' from irritating parasitic sources on high-energy physics accelerators to dedicated electron and position storage rings of unprecedented low emittance, utilizing undulator and wiggler magnets. The evolution through these three generations followed a predicable, science-driven, course towards brighter beams of VUV- and x-radiation. The requirements of future light sources is not so clear. The limit on how emittance has certainly not been reached, and diffraction-limited sources at shorter wavelengths would be the natural progression from previous generations. However, scientists are now looking at other radiation characteristics that might better serve their needs, for example, more coherent power, fast switching polarization, ultra-short (sub-picosecond) time structure, and synchronized beams for pump-probe experiments. This paper discusses some current ideas that might drive the fourth-generation synchrotron light source.
Date: March 1, 1992
Creator: Jackson, A.; Hassenzahl, W. & Meddahi, M.
System: The UNT Digital Library
Two-phase flow modeling with discrete particles (open access)

Two-phase flow modeling with discrete particles

The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for …
Date: March 23, 1992
Creator: Mortensen, G. A. & Trapp, J. A.
System: The UNT Digital Library
Proposed guidelines for using Energy Management and Control Systems for performance monitoring (open access)

Proposed guidelines for using Energy Management and Control Systems for performance monitoring

Monitoring of energy consumption and building operation are important parts of conservation savings analysis, although effective monitoring can be quite expensive. Energy management and Control Systems (EMCSS) contain all of the same equipment that is usually installed for monitoring, however, and can often be used for this application. Since EMCSs are installed in a growing number of commercial buildings, the addition of conventional energy monitoring equipment can be redundant. EMCSs are not designed with monitoring in mind, however. The characteristics of an EMCS are determined by the building's control needs rather than by monitoring needs, so EMCS-based monitoring can have several complicating factors. Differences between the EMCS models, the installed options at sites with the same model, or the degree of system utilization at a site can mean the difference between a system that can be used for monitoring immediately, and one that cannot be used at all. In instituting monitoring programs that include EMCSs as tools, guidelines defining procedures and the required system capabilities would be quite helpful. In this paper, we propose guidelines for EMCS monitoring, based on our evaluation of monitoring procedures in earlier case studies. These guidelines could be used to help in determining whether EMCSs …
Date: March 1, 1992
Creator: Heinemeier, K. & Akbari, H.
System: The UNT Digital Library
Gold Beam Losses at the AGS Booster Injection. (open access)

Gold Beam Losses at the AGS Booster Injection.

Gold beam injection efficiency decreases in proportional to the beam loss in the AGS Booster. A close look shows that large number of electrons, ions, and neutral particles are created when the gold beam scrapes wall. To investigate the neutral particle production due to the beam loss, local vacuum measurement was made during the 1998 run. It shows that the pressure created by the Booster Au{sup 31+} beam loss at injection has a 35 ms decay time constant. The beam loss created pressure bump in the ring is about 20 meters long. When 3 x 10{sup 9} Gold ions scrapes wall, a pressure higher than 10{sup -7} Torr was created. The beam lifetime calculated using these parameters is in agreement with the observed one.
Date: March 29, 1999
Creator: Zhang, S. Y. & Ahrens, L. A.
System: The UNT Digital Library
A Cupronickel Rotating Band Pion Production Target for Muon Colliders. (open access)

A Cupronickel Rotating Band Pion Production Target for Muon Colliders.

A conceptual design is presented for a high power cupronickel pion production target. It forms a circular band in a horizontal plane with approximate dimensions of: 2.5 meters radius, 6 cm high and 0.6 cm thick. The target is continuously rotated at 3 m/s to carry heat away from the production region to a water cooling channel. Bunches of 16 GeV protons with total energies of 270 kl and repetition rates of 15 Hz are incident tangentially to arc of the target along the symmetry axis of a 20 Tesla solenoidal magnetic capture channel. The mechanical layout and cooling setup are described. Results are presented from realistic MARS Monte Carlo computer simulations of the pion yield and energy deposition in the target. ANSYS finite element calculations are beginning to give predictions for the resultant shock heating stresses.
Date: March 29, 1999
Creator: King, B. J.; Weggel, R. J.; Mokhov, N. V. & Moser, S. S.
System: The UNT Digital Library
Precision Magnetic Elements for the SNS Storage Ring. (open access)

Precision Magnetic Elements for the SNS Storage Ring.

Magnetic elements for an accumulator storage ring for a 1 GeV Spallation Neutron Source (SNS) have been under design. The accumulation of very high intensity protons in a storage ring requires beam optical elements of very high purity to minimize higher order resonances in the presence of space charge. The parameters of the elements required by the accumulator lattice design have been reported. The dipoles have a 17cm gap and are 124cm long. The quadrupoles have a physical length to aperture diameter ratio of 40cm/21cm and of 45cm/31cm. Since the elements have a large aperture and short length, optimizing the optical effects of magnet ends is the major design challenge. Two dimensional (2D) computer computations can, at least on paper, produce the desired accuracy internal to magnets, i.e. constant dipole fields and linear quadrupole gradients over the desired aperture to 1 x 10{sup -4}. To minimize undesirable end effects three dimensional (3D) computations can be used to design magnet ends. However, limitations on computations can occur, such as necessary finite boundary conditions, actual properties of the iron employed, hysteresis effects, etc., which are slightly at variance with the assumed properties. Experimental refinement is employed to obtain the desired precision.
Date: March 29, 1999
Creator: Danby, G.; Jackson, J. & Spataro, C.
System: The UNT Digital Library