Charm physics at Fermilab E791 (open access)

Charm physics at Fermilab E791

Experiment 791 at Fermilab`s Tagged Photon Laboratory has just accumulated a high statistics charm sample by recording 20 billion events on 24000 8mm tapes. A 500 GeV/c {pi}{sup {minus}} beam was used with a fixed target and a magnetic spectrometer which now includes 23 silicon microstrip planes for vertex reconstruction. A new data acquisition system read out 9000 events/sec during the part of the Tevatron cycle that delivered beam. Digitization and readout took 50 {mu}S per event. Data was buffered in eight large FIFO memories to allow continuous event building and continuous tape writing to a wall of 42 Exabytes at 9.6 MB/sec. The 50 terabytes of data buffered to tape is now being filtered on RISC CPUs. Preliminary results show D{sup 0} {yields} K{sup {minus}}{pi}{sup +} and D{sup +} {yields} K{sup {minus}}{pi}{pi}{sup +} decays. Rarer decays will be pursued.
Date: May 26, 1992
Creator: Amato, S.; Anjos, J. C.; Bediaga, I.; Costa, I.; de Mello Neto, J. R. T.; de Miranda, J. et al.
System: The UNT Digital Library
Charm physics at Fermilab E791 (open access)

Charm physics at Fermilab E791

Experiment 791 at Fermilab's Tagged Photon Laboratory has just accumulated a high statistics charm sample by recording 20 billion events on 24000 8mm tapes. A 500 GeV/c [pi][sup [minus]] beam was used with a fixed target and a magnetic spectrometer which now includes 23 silicon microstrip planes for vertex reconstruction. A new data acquisition system read out 9000 events/sec during the part of the Tevatron cycle that delivered beam. Digitization and readout took 50 [mu]S per event. Data was buffered in eight large FIFO memories to allow continuous event building and continuous tape writing to a wall of 42 Exabytes at 9.6 MB/sec. The 50 terabytes of data buffered to tape is now being filtered on RISC CPUs. Preliminary results show D[sup 0] [yields] K[sup [minus]][pi][sup +] and D[sup +] [yields] K[sup [minus]][pi][pi][sup +] decays. Rarer decays will be pursued.
Date: May 26, 1992
Creator: Amato, S.; Anjos, J. C.; Bediaga, I.; Costa, I.; de Mello Neto, J. R. T.; de Miranda, J. et al.
System: The UNT Digital Library
Basic criticality relations for gas core design (open access)

Basic criticality relations for gas core design

Minimum critical fissile concentrations are calculated for U-233, U-235, Pu-239, and Am-242m mixed homogeneously with hydrogen at temperatures to 15,000K. Minimum critical masses of the same mixtures in a 1000 liter sphere are also calculated. It is shown that propellent efficiencies of a gas core fizzler engine using Am-242m as fuel would exceed those in a solid core engine as small as 1000L operating at 100 atmospheres pressure. The same would be true for Pu-239 and possibly U-233 at pressures of 1000 atm. or at larger volumes.
Date: May 22, 1992
Creator: Tanner, J. E.
System: The UNT Digital Library
Choice and meaning in the quantum universe (open access)

Choice and meaning in the quantum universe

This report discusses whether the events that occur in the universe evolve deterministicly or randomly or both. (LSP).
Date: May 22, 1992
Creator: Stapp, Henry P.
System: The UNT Digital Library
Choice and meaning in the quantum universe (open access)

Choice and meaning in the quantum universe

This report discusses whether the events that occur in the universe evolve deterministicly or randomly or both. (LSP).
Date: May 22, 1992
Creator: Stapp, H. P.
System: The UNT Digital Library
Microindentation hardness evaluation of iridium alloy clad vent set cups (open access)

Microindentation hardness evaluation of iridium alloy clad vent set cups

An iridium alloy, DOP-26, is used as cladding for {sup 238}PuO{sup 2} fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration`s Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that …
Date: May 15, 1992
Creator: Ulrich, G. B.; DeRoos, L. F. & Stinnette, S. E.
System: The UNT Digital Library
Microindentation hardness evaluation of iridium alloy clad vent set cups (open access)

Microindentation hardness evaluation of iridium alloy clad vent set cups

An iridium alloy, DOP-26, is used as cladding for {sup 238}PuO{sup 2} fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that …
Date: May 15, 1992
Creator: Ulrich, George B.; DeRoos, Larry F. & Stinnette, Samuel E.
System: The UNT Digital Library
[SIAM conference on optimization] (open access)

[SIAM conference on optimization]

Abstracts are presented of 63 papers on the following topics: large-scale optimization, interior-point methods, algorithms for optimization, problems in control, network optimization methods, and parallel algorithms for optimization problems.
Date: May 10, 1992
Creator: unknown
System: The UNT Digital Library
[SIAM conference on optimization] (open access)

[SIAM conference on optimization]

Abstracts are presented of 63 papers on the following topics: large-scale optimization, interior-point methods, algorithms for optimization, problems in control, network optimization methods, and parallel algorithms for optimization problems.
Date: May 10, 1992
Creator: unknown
System: The UNT Digital Library
Optimization of a VISAR for measuring flyer-plate velocities (open access)

Optimization of a VISAR for measuring flyer-plate velocities

VISAR (Velocity Interferometer System for Any Reflector) is commonly used for measuring flyer-plate velocities up to 6 km/s. Flyer plates can travel as much as 1 mm, which is large compared to usual depth-of-focus requirements for VISARs. Flyer plates are explosively driven, or driven by some other very energetic means; as such, they must be tested in a chamber, which will contain the explosion. Routing the laser beam to the chamber and the signal beam to the VISAR can be done safely and easily in multi-mode optical fibers. We have optimized a fiber-coupled VISAR system for measuring flyer-plate velocities. This system given constant signal levels over the full travel of the flyer plate. Furthermore, the signal-collection efficiency is maximized, which allows use of a moderately sized laser. We also have optimized the VISAR cavity so it does not limit the system efficiency while giving a velocity sensitivity of about 1 km/s per fringe. 5 refs.
Date: May 6, 1992
Creator: Sweatt, W. C.; Crump, O. B., Jr. & Brigham, W. P.
System: The UNT Digital Library
Accelerator prospects for photon-photon physics (open access)

Accelerator prospects for photon-photon physics

This paper provides an overview of the accelerators in the world where two-photon physics could be carried out in the future. The list includes facilities where two-photon physics is already an integral part of the scientific program but also mentions some other machines where initiating new programs may be possible.
Date: May 1, 1992
Creator: Hutton, A.
System: The UNT Digital Library
Accelerator prospects for photon-photon physics (open access)

Accelerator prospects for photon-photon physics

This paper provides an overview of the accelerators in the world where two-photon physics could be carried out in the future. The list includes facilities where two-photon physics is already an integral part of the scientific program but also mentions some other machines where initiating new programs may be possible.
Date: May 1, 1992
Creator: Hutton, A.
System: The UNT Digital Library
An adaptive algorithm for modifying hyperellipsoidal decision surfaces (open access)

An adaptive algorithm for modifying hyperellipsoidal decision surfaces

The LVQ algorithm is a common method which allows a set of reference vectors for a distance classifier to adapt to a given training set. We have developed a similar learning algorithm, LVQ-MM, which manipulates hyperellipsoidal cluster boundaries as opposed to reference vectors. Regions of the input feature space are first enclosed by ellipsoidal decision boundaries, and then these boundaries are iteratively modified to reduce classification error. Results obtained by classifying the Iris data set are provided.
Date: May 1, 1992
Creator: Kelly, P. M.; Hush, D. R. & White, J. M.
System: The UNT Digital Library
Adjacency-blurring-effect of scenes modeled by the radiosity method (open access)

Adjacency-blurring-effect of scenes modeled by the radiosity method

In this paper we describe a method to simulate images through a scattering atmosphere. We compute the scattering of light from adjacent surfaces into the field-of-view (FOV) with the extended radiosity method. Our simulation takes aerosol scattering phase functions and ground bidirectional reflectance distributions (BRDF) into account. 10 refs.
Date: May 1, 1992
Creator: Borel, C. C. & Gerstl, S. A. W.
System: The UNT Digital Library
Advanced materials development for fossil energy conversion applications (open access)

Advanced materials development for fossil energy conversion applications

Research activities being conducted as part of this project include: (1) fundamental studies of electrochemical processes occurring at surfaces and interfaces in fuel cells, and (2) development of novel materials synthesis and processing methodologies for fossil energy conversion applications. Complex impedance and dc polarization studies of the electrocatalytic activity at the cathode have allowed intrinsic materials properties to be separated from extrinsic properties related to morphology. Mixed conduction in cathode materials was shown to dramatically enhance electrocatalytic activity with this approach. Combustion synthesis methods were used to prepare multicomponent perovskite catalysts in the La{sub 1-x}Sr{sub x}Co{sub 1-y}Fe{sub y}O{sub 3} system. Electronic properties of these catalysts can be altered by adjusting the composition, which affects both catalytic activity and selectivity. Inverse micelles have been utilized to prepare nanosized nickel sulfide particles, which show promise as hydrodesulfurization catalysts for liquefied coal. Self-assembling organic monolayers and derivatized inorganic surfaces have been used to control nucleation and crystal morphology of inorganic phases.
Date: May 1, 1992
Creator: Bates, J. L.; Chick, L. A.; Kingsley, J. J.; Pederson, L. R.; Weber, W. J.; Youngblood, G. E. et al.
System: The UNT Digital Library
Advanced materials development for fossil energy conversion applications (open access)

Advanced materials development for fossil energy conversion applications

Research activities being conducted as part of this project include: (1) fundamental studies of electrochemical processes occurring at surfaces and interfaces in fuel cells, and (2) development of novel materials synthesis and processing methodologies for fossil energy conversion applications. Complex impedance and dc polarization studies of the electrocatalytic activity at the cathode have allowed intrinsic materials properties to be separated from extrinsic properties related to morphology. Mixed conduction in cathode materials was shown to dramatically enhance electrocatalytic activity with this approach. Combustion synthesis methods were used to prepare multicomponent perovskite catalysts in the La{sub 1-x}Sr{sub x}Co{sub 1-y}Fe{sub y}O{sub 3} system. Electronic properties of these catalysts can be altered by adjusting the composition, which affects both catalytic activity and selectivity. Inverse micelles have been utilized to prepare nanosized nickel sulfide particles, which show promise as hydrodesulfurization catalysts for liquefied coal. Self-assembling organic monolayers and derivatized inorganic surfaces have been used to control nucleation and crystal morphology of inorganic phases.
Date: May 1, 1992
Creator: Bates, J. L.; Chick, L. A.; Kingsley, J. J.; Pederson, L. R.; Weber, W. J.; Youngblood, G. E. et al.
System: The UNT Digital Library
Aerosol penetration through a seismically loaded shear wall (open access)

Aerosol penetration through a seismically loaded shear wall

An experimental study was performed to measure the aerosol penetration through a reinforced concrete shear wall after simulated seismic damage. Static load-cycle testing, to stress levels sufficient to induce visible shear cracking, was used to simulate the earthquake loading. Air permeability tests were performed both before and after the simulated seismic loading damaged the structure. Aerosol penetration measurements were conducted on the cracked shear wall structure using 0.10 {mu}m monodisperse particles. The measured aerosol number penetration through the cracked shear wall was 0.5%. 7 refs.
Date: May 1, 1992
Creator: Farrar, C. R. & Girrens, S. P.
System: The UNT Digital Library
Los Alamos National Laboratory and technology transfer (open access)

Los Alamos National Laboratory and technology transfer

From its beginning in 1943, Los Alamos National Laboratory (Los Alamos) has traditionally used science and technology to fine creative, but practical solutions to complex problems. Los Alamos National Laboratory is operated by the University of California, under contact to the Department of Energy. We are a Government Owned-contractor Operated (GOCO) facility, and a Federally-funded research and Development Center (FFRDC). At Los Alamos, our mission is to apply science and engineering capabilities to problems of national security. Recently our mission has been broadened to include technology transfer to ensure the scientific and technical solutions are available to the marketplace. We are, in staff and technical capabilities, one of the worlds largest multidisciplinary, multiprogram laboratories. We conduct extensive research in energy, nuclear safeguards and security, biomedical science, conventional defense technologies, space science, computational science, environmental protection and cleanup, materials science, and other basic sciences. Since 1980, by a series of laws and executive orders, the resources of the federal laboratories have been made increasingly available to private industry via technology transfer efforts. Los Alamos National Laboratory uses a variety of technology transfer methods including laboratory visits, cooperative research, licensing, contract research, user facility access, personnel exchanges, consulting, publications, and workshops, seminars …
Date: May 1, 1992
Creator: Bearce, T. D.
System: The UNT Digital Library
Alpha particle diagnostics using impurity pellet injection (open access)

Alpha particle diagnostics using impurity pellet injection

We have proposed using impurity injection to measure the energy distribution of the fast confined alpha particles in a reacting plasma. The ablation cloud surrounding the injected pellet is thick enough that an equilibrium fraction F{sub o}{sup {infinity}}(E) of the incident alphas should be neutralized as they pass through the cloud. By observing neutrals created in the large spatial region of the cloud which is expected to be dominated by the helium-like ionization state, e.g., Li{sup +} ions, we can determine the incident alpha distribution dn{sub He}2+/dE from the measured energy distribution of neutral helium atoms. Initial experiments were performed on TEXT in which we compared pellet penetration with our impurity pellet ablation model, and measured the spatial distribution of various ionization states in carbon pellet clouds. Experiments have recently begun on TFTR with the goal of measuring the alpha particle energy distribution during D-T operation in 1993--94. A series of preliminary experiments are planned to test the diagnostic concept. The first experiments will observe neutrals from beam-injected deuterium ions and the high energy {sup 3}He tail produced during ICH minority heating on TFTR interacting with the cloud. We will also monitor by line radiation the charge state distributions in …
Date: May 1, 1992
Creator: Fisher, R. K.; McChesney, J. M.; Howald, A. W.; Parks, P. B.; Snipes, J. A.; Terry, J. L. et al.
System: The UNT Digital Library
Alpha particle diagnostics using impurity pellet injection (open access)

Alpha particle diagnostics using impurity pellet injection

We have proposed using impurity injection to measure the energy distribution of the fast confined alpha particles in a reacting plasma. The ablation cloud surrounding the injected pellet is thick enough that an equilibrium fraction F{sub o}{sup {infinity}}(E) of the incident alphas should be neutralized as they pass through the cloud. By observing neutrals created in the large spatial region of the cloud which is expected to be dominated by the helium-like ionization state, e.g., Li{sup +} ions, we can determine the incident alpha distribution dn{sub He}2+/dE from the measured energy distribution of neutral helium atoms. Initial experiments were performed on TEXT in which we compared pellet penetration with our impurity pellet ablation model, and measured the spatial distribution of various ionization states in carbon pellet clouds. Experiments have recently begun on TFTR with the goal of measuring the alpha particle energy distribution during D-T operation in 1993--94. A series of preliminary experiments are planned to test the diagnostic concept. The first experiments will observe neutrals from beam-injected deuterium ions and the high energy {sup 3}He tail produced during ICH minority heating on TFTR interacting with the cloud. We will also monitor by line radiation the charge state distributions in …
Date: May 1, 1992
Creator: Fisher, R. K.; McChesney, J. M.; Howald, A. W.; Parks, P. B. (General Atomics, San Diego, CA (United States)); Snipes, J. A.; Terry, J. L. et al.
System: The UNT Digital Library
Analysis of a piping system for requalification (open access)

Analysis of a piping system for requalification

This paper discusses the global stress analysis required for the seismic/structural requalification of a reactor secondary piping system in which minor defects (flaws) were discovered during a detailed inspection. The flaws in question consisted of weld imperfections. Specifically, it was necessary to establish that the stresses at the flawed sections did not exceed the allowables and that the fatigue life remained within acceptable limits. At the same time the piping system had to be qualified for higher earthquake loads than those used in the original design. To accomplish these objectives the nominal stress distributions in the piping system under the various loads (dead load, thermal load, wind load and seismic load) were determined. First a best estimate finite element model was developed and calculations were performed using the piping analysis modules of the ANSYS Computer Code. Parameter studies were then performed to assess the effect of physically reasonable variations in material, structural, and boundary condition characteristics. The nominal stresses and forces so determined, provided input for more detailed analyses of the flawed sections. Based on the reevaluation, the piping flaws were judged to be benign, i.e., the piping safety margins were acceptable inspite of the increased seismic demand. 13 refs.
Date: May 1, 1992
Creator: Hsieh, B. J. & Tang, Yu
System: The UNT Digital Library
Analysis of coolability of the control rods of a Savannah River Site production reactor with loss of normal forced convection cooling (open access)

Analysis of coolability of the control rods of a Savannah River Site production reactor with loss of normal forced convection cooling

An analytical study of the coolability of the control rods in the Savannah River Site (SRS) K-Production Reactor under conditions of loss of normal forced convection cooling has been performed. The study was performed as part of the overall safety analysis of the reactor supporting its restart. The analysis addresses the buoyancy-driven flow over the control rods that occurs when forced cooling is lost, and the limit of critical heat flux that sets the acceptance criteria for the study. The objective of the study is to demonstrate that the control rods will remain cooled at powers representative of those anticipated for restart of the reactor. The study accomplishes this objective with a very tractable simplified analysis for the modest restart power. In addition, a best-estimate calculation is performed, and the results are compared to results from sub-scale scoping experiments. 5 refs.
Date: May 1, 1992
Creator: Easterling, T. C.; Hightower, N. T.; Smith, D. C. & Amos, C. N.
System: The UNT Digital Library
Antiproton driven microfission-fusion on closer inspection (open access)

Antiproton driven microfission-fusion on closer inspection

A closer look at the energetics of antiproton annihilation in real systems, coupled to hydrodynamics, materials strength, particle transport, equations of state, and related interactions is necessary to assess ultimate viability. The systematics of antiproton microfission-fusion are the subject of this analysis, as well as technology constraints.
Date: May 1, 1992
Creator: Wienke, B. R.
System: The UNT Digital Library
Aperture coupling measurement in a test chamber for the Advanced Photon Source (APS) (open access)

Aperture coupling measurement in a test chamber for the Advanced Photon Source (APS)

Aperture coupling measurements have been made using two identical rectangular chambers. A common wall between them has holes of various size, thickness, shape and number. The transverse electromagnetic (TEM) wave, which propagates in one rectangular chamber, couples through the aperture and radiates into the other chamber. The measured results are compared with the diffraction model and used to estimate the coupling impedance of a circulating beam. The results of these measurements was applied to the detailed design of some of the vacuum components in the Advanced Photon Source.
Date: May 1, 1992
Creator: Song, J. J.; Zhou, J. H. & Kustom, R. L.
System: The UNT Digital Library