Production of the charmed strange baryon. xi. /sub c//sup +/ by neutrons (open access)

Production of the charmed strange baryon. xi. /sub c//sup +/ by neutrons

We report on the observation of a narrow resonance at a mass of 2450 MeV/c/sup 2/ in the final states ..lambda..K/sup -/..pi../sup +/..pi../sup +/ and ..sigma../sup 0/K/sup -/..pi../sup +/..pi../sup +/. The mass, width, lifetime, and decay modes support the interpretation of a hadronically produced charm-strange baryon, the ..xi../sub c//sup +/. We present our preliminary measurements of the lifetime, and the ..lambda.., x/sub feynman,/ and p/sub t/ dependence of the state.
Date: December 1, 1986
Creator: unknown
System: The UNT Digital Library
Concluding talk-seminar on critical issues in development of new linear colliders (open access)

Concluding talk-seminar on critical issues in development of new linear colliders

The growth of particle colliders is summarized, with their collision energy in the frame of the elementary constituents given for numerous specific machines. The logic concerning the design of electron-positron colliders and definition of parameters are briefly discussed. Several issues are covered which are presently uncertain, including beamstrahlung and interaction among beams of transverse dimensions in the angstrom range. Alternate power sources and their economy are considered as well as superconducting structures. (LEW)
Date: December 1, 1986
Creator: Panofsky, W.K.H.
System: The UNT Digital Library
Non-thermal AGN models (open access)

Non-thermal AGN models

The infrared, optical and x-ray continua from radio quiet active galactic nuclei (AGN) are explained by a compact non-thermal source surrounding a thermal ultraviolet emitter, presumably the accretion disk around a supermassive black hole. The ultraviolet source is observed as the ''big blue bump.'' The flat (..cap alpha.. approx. = .7) hard x-ray spectrum results from the scattering of thermal ultraviolet photons by the flat, low energy end of an electron distribution ''broken'' by Compton losses; the infrared through soft x-ray continuum is the synchrotron radiation of the steep, high energy end of the electron distribution. Quantitative fits to specific AGN result in models which satisfy the variability constraints but require electron (re)acceleration throughout the source. 11 refs., 1 fig.
Date: December 1, 1986
Creator: Band, D.L.
System: The UNT Digital Library
Open accelerating structures (open access)

Open accelerating structures

An ''Open'' Accelerating Structure must first perform the mode matching function of any accelerating structure, i.e., it must couple an incoming free field to an accelerating mode. The simplest open periodic structure that can be considered is a grating. There has been an attempt to employ an inverse Purcell effect by illuminating a grating from directly above with plane parallel light and passing the particles over the surface of the grating at right angles to the lines. Unfortunately, it has been shown by the Lawson theorem that these geometries fail to accelerate relativistic particles. This paper will restate Lawson's theorem but show that it applies only to the simple two-dimensional situation. It is shown that accelerating fields above grating can be made to fall off exponentially from that surface. Several structures are examined that deal with the problem of fields spreading over the whole grating surface.
Date: December 1, 1986
Creator: Palmer, Robert B.
System: The UNT Digital Library
Hadron cascades produced by electromagnetic cascades (open access)

Hadron cascades produced by electromagnetic cascades

A method for calculating high energy hadron cascades induced by multi-GeV electron and photon beams is described. Using the EGS4 computer program, high energy photons in the EM shower are allowed to interact hadronically according to the vector meson dominance (VMD) model, facilitated by a Monte Carlo version of the dual multistring fragmentation model which is used in the hadron cascade code FLUKA. The results of this calculation compare very favorably with experimental data on hadron production in photon-proton collisions and on the hadron production by electron beams on targets (i.e., yields in secondary particle beam lines). Electron beam induced hadron star density contours are also presented and are compared with those produced by proton beams. This FLUKA-EGS4 coupling technique could find use in the design of secondary beams, in the determination high energy hadron source terms for shielding purposes, and in the estimation of induced radioactivity in targets, collimators and beam dumps.
Date: December 1, 1986
Creator: Nelson, W. R.; Jenkins, T. M. & Ranft, J.
System: The UNT Digital Library
The development of a cavitation free sodium pump for the breeder reactor (open access)

The development of a cavitation free sodium pump for the breeder reactor

The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. After each modification intensive testing was conducted with feedback to established design criteria. The results obtained from the final configuration showed excellent cavitation performance. This configuration was then machined on the full scale impeller and tested. The results confirmed acceptable performance in the entire range of operating conditions. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents the experimental techniques employed, and presents a sample of the experimental results.
Date: December 1, 1986
Creator: Baladi, J. Y. & Nyilas, C. P.
System: The UNT Digital Library
Precipitation of krypton in an amorphous Ti-Cr alloy. [Ti-Cr Thin Films] (open access)

Precipitation of krypton in an amorphous Ti-Cr alloy. [Ti-Cr Thin Films]

Results of a TEM investigation of the microstructural changes produced by the room temperature implantation of energetic Kr/sup +/ ions into a glassy Ti-Cr thin film are reported. As in other metals, the Kr precipitates as solid crystallites. The precipitation of crystalline Kr is accompanied by ultrafine crystallization of the metal host around each Kr crystal. With increasing fluence, the Kr precipitates grow to a critical size at which they melt, and the adjacent fine metal crystals disappear. A new TEM imaging technique is described briefly which utilizes the small angle electron scattering fine structure and which in principle is capable of revealing all fine particles simultaneously.
Date: December 1, 1986
Creator: Allen, C. W. & Birtcher, R. C.
System: The UNT Digital Library
Integrated digital control and man-machine interface for complex remote handling systems (open access)

Integrated digital control and man-machine interface for complex remote handling systems

The Advanced Integrated Maintenance System (AIMS) is part of a continuing effort within the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory to develop and extend the capabilities of remote manipulation and maintenance technology. The AIMS is a totally integrated approach to remote handling in hazardous environments. State-of-the-art computer systems connected through a high-speed communication network provide a real-time distributed control system that supports the flexibility and expandability needed for large integrated maintenance applications. A Man-Machine Interface provides high-level human interaction through a powerful color graphics menu-controlled operator console. An auxiliary control system handles the real-time processing needs for a variety of support hardware. A pair of dedicated fiber-optic-linked master/slave computer system control the Advanced Servomanipulator master/slave arms using powerful distributed digital processing methods. The FORTH language was used as a real-time operating and development environment for the entire system, and all of these components are integrated into a control room concept that represents the latest advancements in the development of remote maintenance facilities for hazardous environments.
Date: December 1, 1986
Creator: Rowe, J.C.; Spille, R.F. & Zimmermann, S.D.
System: The UNT Digital Library
Simulation of uranium transport with variable temperature and oxidation potential: The computer program THCC (Thermo-Hydro-Chemical Coupling) (open access)

Simulation of uranium transport with variable temperature and oxidation potential: The computer program THCC (Thermo-Hydro-Chemical Coupling)

A simulator of reactive chemical transport has been constructed with the capabilities of treating variable temperatures and variable oxidation potentials within a single simulation. Homogeneous and heterogeneous chemical reactions are simulated at temperature-dependent equilibrium, and changes of oxidation states of multivalent elements can be simulated during transport. Chemical mass action relations for formation of complexes in the fluid phase are included explicitly within the partial differential equations of transport, and a special algorithm greatly simplifies treatment of reversible precipitation of solid phases. This approach allows direct solution of the complete set of governing equations for concentrations of all aqueous species and solids affected simultaneously by chemical and physical processes. Results of example simulations of transport, along a temperature gradient, of uranium solution species under conditions of varying pH and oxidation potential and with reversible precipitation of uraninite and coffinite are presented. The examples illustrate how inclusion of variable temperature and oxidation potential in numerical simulators can enhance understanding of the chemical mechanisms affecting migration of multivalent waste elements.
Date: December 1986
Creator: Carnahan, C. L.
System: The UNT Digital Library
Kaon decay amplitudes using staggered fermions (open access)

Kaon decay amplitudes using staggered fermions

A status report is given of an attempt, using staggered fermions to calculate the real and imaginary parts of the amplitudes for K ..-->.. ..pi pi..,. Semi-quantitative results are found for the imaginary parts, and these suggest that epsilon' might be smaller than previously expected in the standard model.
Date: December 1, 1986
Creator: Sharpe, S.R.
System: The UNT Digital Library
Modes of Storage Ring Coherent Instabilities (open access)

Modes of Storage Ring Coherent Instabilities

Longitudinal impedance in a beam and various modes of longitudinal coherent instabilities are discussed. The coasting beam coherent instability, microwave instability, and single-bunch longitudinal coherent instabilities are considered. The Vlasov equation is formulated, and a method of solving it is developed. The synchrotron modes are treated, which take the possible bunch shape distortion fully into consideration. A method of treating the synchrotron mode coupling in the case of a small bunch is discussed which takes advantage of the fact that only a few of the synchrotron modes can contribute in such a case. The effect of many bunches on the coherent motion of the beam and the longitudinal symmetric coupled bunch modes are discussed. The transverse impedance is then introduced, and the transverse coasting beam instability is discussed. Various bunched beam instabilities are discussed, including both single bunch instabilities and coupled bunch instabilities. The Vlasov equation for transverse as well as longitudinal motion of particles is introduced as well as a method of solving it within a linear approximation. Head-tail modes and short bunch instabilities and strong coupling instabilities in the long bunch case are covered. (LEW)
Date: December 1986
Creator: Wang, Jiunn-Ming
System: The UNT Digital Library
Recent results from the Crystal Ball experiment (open access)

Recent results from the Crystal Ball experiment

Several recent analyses from the Crystal Ball collaboration are reviewed. The major topics discussed are the search for new states in radiative UPSILON(1S) decays, the search for lepton number-violating and inclusive eta decay modes of the tau, and results from ..gamma gamma.. physics.
Date: December 1, 1986
Creator: Lowe, S.T.
System: The UNT Digital Library
Proceedings of the second workshop on hydrologic and geochemical monitoring in the Long Valley Caldera (open access)

Proceedings of the second workshop on hydrologic and geochemical monitoring in the Long Valley Caldera

A workshop was held to review the results of hydrologic and geochemical monitoring and scientific drilling in the Long Valley caldera. Such monitoring is being done to detect changes in the hydrothermal system induced by ongoing magmatic and techonic processes. Data from a 2400-ft deep core hole completed in June 1986 were presented at the 1986 workshop and participants discussed the need and rationale for siting locations for future scientific drilling in the caldera.
Date: December 1, 1986
Creator: Sorey, M. L.; Farrar, C. D. & Wollenberg, H. A. (eds.)
System: The UNT Digital Library
A self-similar approach to the explosion of droplets by a high energy laser beam (open access)

A self-similar approach to the explosion of droplets by a high energy laser beam

A model has been constructed in which a small droplet is exploded by the absorption of energy from a high energy laser beam. The beam flux is so high that it is assumed that a plasma is formed. A single-fluid model of a plasma droplet interacting with laser radiation is used. Selfsimilarity is invoked to reduce the spherically symmetric problem involving hydrodynamics and Maxwell's equations to quadrature. It is shown analytically that the model reproduces in qualitative manner certain features observed experimentally.
Date: December 30, 1986
Creator: Chitanvis, S.M.
System: The UNT Digital Library
The operator interface for the Mirror Fusion Test Facility (open access)

The operator interface for the Mirror Fusion Test Facility

The uncertain and most likely changing nature of a large experimental facility like MFTF, as well as its large number of control and monitor points, ruled against the traditional hardware approach involving walls of knobs, dials, oscilloscopes, and strip chart recorders. Rather, from the beginning, project management specified computer control of all systems, and operation of the complete MFTF under an integrated computer control system became a major engineering goal. The Integrated Controls and Diagnostics (ICADS) group was charged with the design and implementation of this control system. We designed a control system with an extremely flexible operator interface which uses computer generated CRT displays for output and pointing devices such as touch sensitive CRT overlays, mice, and joysticks for input. Construction of MFTF was completed at the end of 1985 within the project budget of $241.6M and was followed immediately by a 5 month long acceptance test. During this period (known as PACE test) operators, engineers, and physicists successfully used our computer control system daily to test MFTF. Much of their willingness to forsake the traditional hands-on hardware approach to testing was a result of the powerful and flexible operator interface to the MFTF control system. In this paper, …
Date: December 1, 1986
Creator: Lang, N. C.
System: The UNT Digital Library
Peat deposits in Panama: Their potential for use in energy applications (open access)

Peat deposits in Panama: Their potential for use in energy applications

A major peak bog has been discovered in the Changuinola area of Panama. The bog averages 8-m deep, is thought to be 82 km/sup 2/, in area and the peat has an ash content of about 4%. It is estimated that this size peat bog could support a 30-MW power plant for 360 years. Preliminary cost estimates for using the peat in an electrical power plant give an estimated cost of electricity of 0.09$US/kWh if wet mining is used and 0.079$US/kWh if milled peat is used. 2 refs., 4 figs.
Date: December 1, 1986
Creator: Ramirez, A.; Thayer, G.; Cohen, A.D. & Allen, A.
System: The UNT Digital Library
Station blackout at nuclear power plants: Radiological implications for nuclear war (open access)

Station blackout at nuclear power plants: Radiological implications for nuclear war

Recent work on station blackout is reviewed its radiological implications for a nuclear war scenario is explored. The major conclusion is that the effects of radiation from many nuclear weapon detonations in a nuclear war would swamp those from possible reactor accidents that result from station blackout.
Date: December 1, 1986
Creator: Shapiro, C.S.
System: The UNT Digital Library
The microlasertron: An efficient switched-power source of mm wavelength radiation (open access)

The microlasertron: An efficient switched-power source of mm wavelength radiation

An extension of W. Willis' ''Switched Power Linac'' is studied. Pulsed laser light falls on a photocathode wire, or wires, within a simple resonant structure. The resulting pulsed electron current between the wire and the structure wall drives the resonant field, and rf energy is extracted in the mm to cm wavelength range. Various geometries are presented, including one consisting of a simple array of parallel wires over a plane conductor. Results from a one-dimensional simulation are presented.
Date: December 1, 1986
Creator: Palmer, Robert B.
System: The UNT Digital Library
A core hole in the southwestern moat of the Long Valley caldera: Early results (open access)

A core hole in the southwestern moat of the Long Valley caldera: Early results

A continuously cored hole penetrated 715m into the southwestern moat of the Long Valley caldera. Temperatures in the post-caldera deposits increase rapidly with depth over the upper 335m to 202/sup 0/C, then remain nearly isothermal into the Bishop Tuff to the bottom of the hole. The depth to the Bishop is the shallowest, and the temperatures observed are among the highest in holes drilled in the caldera. The hole identifies a potential geothermal resource for the community of Mammoth Lakes, constrains the position of the principal heat source for the caldera's hydrothermal system, and serves as access for monitoring changes in water level, temperatures, and fluid chemistry.
Date: December 1, 1986
Creator: Wollenberg, H. A.; Sorey, M. L.; Farrar, C. D.; White, A. F.; Flexser, S. & Bartel, L. C.
System: The UNT Digital Library
Helium circulator design considerations for modular high temperature gas-cooled reactor plant (open access)

Helium circulator design considerations for modular high temperature gas-cooled reactor plant

Efforts are in progress to develop a standard modular high temperature gas-cooled reactor (MHTGR) plant that is amenable to design certification and serial production. The MHTGR reference design, based on a steam cycle power conversion system, utilizes a 350 MW(t) annular reactor core with prismatic fuel elements. Flexibility in power rating is afforded by utilizing a multiplicity of the standard module. The circulator, which is an electric motor-driven helium compressor, is a key component in the primary system of the nuclear plant, since it facilitates thermal energy transfer from the reactor core to the steam generator; and, hence, to the external turbo-generator set. This paper highlights the helium circulator design considerations for the reference MHTGR plant and includes a discussion on the major features of the turbomachine concept, operational characteristics, and the technology base that exists in the US.
Date: December 1, 1986
Creator: McDonald, C. F. & Nichols, M. K.
System: The UNT Digital Library
Wakefield effects in a linear collider (open access)

Wakefield effects in a linear collider

In this paper the wakefields for the Stanford Linear Accelerator Center (SLAC) accelerating structure are first discussed, and then some considerations dealing with the longitudinal wakefields are described. The main focus is on the effects of the transverse wakefield on the beam, including the case when there is an energy variation along the bunch. The use of an energy spread to inhibit emittance growth in a linac, indeed to damp the oscillations of the core of the bunch to below the unperturbed betatron oscillations, (in a process that is similar to Landau Damping) is qualitatively detailed. The example of the SLC, including errors, is also in detail.
Date: December 1, 1986
Creator: Bane, K.L.F.
System: The UNT Digital Library
High current density magnets for INTOR and TIBER (open access)

High current density magnets for INTOR and TIBER

The adoption of high current density, high field, superconducting magnets for INTOR and TIBER would prove beneficial. When combined with improved radiation tolerance of the magnets to minimize the inner leg shielding, a substantial reduction in machine dimensions and capital costs can be achieved. Fortunately, cable-in-conduit conductors (CICC) which are capable of the desired enhancements are being developed. Because conductor stability in a CICC depends more on the trapped helium enthalpy, rather than the copper resistivity, higher current densities of the order of 40 A/mm/sup 2/ at 12 T are possible. Radiation damage to the copper stabilizer is less important because the growth in resistance is a second-order effect on stability. Such CICC conductors lend themselves naturally to niobium-tin utilization, with the benefits of the high current-sharing temperature of this material being taken to advantage in absorbing radiation heating. When the helium coolant is injected at near the critical pressure, Joule-Thompson expansion in the flow path tends to stabilize the fluid temperature at under 6 K. Thus, higher fields, as well as higher current densities, can be considered for INTOR or TIBER.
Date: December 1, 1986
Creator: Miller, J. R.; Henning, C. D.; Kerns, J. A.; Slack, D. S.; Summers, L. T. & Zbasnik, J. P.
System: The UNT Digital Library
Radiation associated with an inertial confinement fusion laser system (open access)

Radiation associated with an inertial confinement fusion laser system

The primary objective the LLNL Laser Fusion Program is to understand and develop the science and technology of inertial confinement fusion. Nova, a 100-TW/100-kJ laser system, has demonstrated efficient compression, ignition, and burn of D-T fusion fuel. The LLNL fusion computer program (LASNEX) and experiments strongly support achieving high gain with the proposed multi-MJ laser system. In this paper, I examine the prompt and residual radiations associated with these laser systems. 3 refs., 6 figs., 4 tabs.
Date: December 3, 1986
Creator: Singh, M.S.
System: The UNT Digital Library
Proceedings of the regional electromagnetic workshop at Argonne National Laboratory (open access)

Proceedings of the regional electromagnetic workshop at Argonne National Laboratory

Separate abstracts were entered into the data base for each of the 7 included papers. (MOW)
Date: December 1, 1986
Creator: Turner, L.R. (ed.)
System: The UNT Digital Library