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Status of the glueballs (open access)

Status of the glueballs

If you assume as input axioms: (1) QCD is correct; and (2) the OZI rule is universal for weakly coupled glue in disconnected Zweig diagrams where the disconnection is due to the creation or annihilation of new flavor(s) of quark(s), then the BNL/CCNY g/sub T/(2010), g/sub T/'(2220) and g/sub T/(2360) observed in ..pi../sup -/p ..-->.. phi phi n are produced by 1-3 primary glueballs. One or two broad primary glueballs could in principle break down the OZI suppression and mix with one or two quark states which accidentally have the same quantum numbers and nearly the same mass. However the simplest explanation of the rather unusual characteristics of our data is that we have found a triplet of J/sup PC/ = 2/sup + +/ glueball states. Since our input axioms are in good agreement with experiments and merely represent modern QCD practice, we have very probably discovered 1-3 J/sup PC/ = 2/sup + +/ glueballs. The iota(1440) and the theta(1700) observed in J/psi radiative decay are glueball candidates. The pros and cons of which are discussed briefly here. 41 references.
Date: August 3, 1983
Creator: Lindenbaum, S. J.
System: The UNT Digital Library
Inversion approach for thermal data from a convecting hydrothermal system (open access)

Inversion approach for thermal data from a convecting hydrothermal system

Efforts to invert thermal data from 13 deep geothermal wells, and from additional shallow heat-flow holes, in order to determine the age and total flow rate of the Salton Sea hydrothermal system are described. The data were inverted for a very restrictive model: single-phase, horizontal flow along prescribed flowlines in a single aquifer bounded by an impermeable cap and base. With simplifying assumptions, the results are shown to depend on only two parameters, the system age, and the aquifer/cap thickness ratio. The surface gradient and temperature distribution within the cap are calculated analytically for all possible parameter values. Those parameters producing temperatures that agree with observations are identified, and the range of acceptable parameters is reduced by conclusions drawn from other geophysical data. The cap thickness is inferred to be 500m from thermal and lithologic data from the wells. The aquifer thickness is limited to less than 2500m by seismic, resistivity and magnetic data. It is concluded that if this model is valid, the system age is constrained between 3000 and 20,000 years.
Date: August 1, 1983
Creator: Kasameyer, P.; Younker, L. & Hanson, J.
System: The UNT Digital Library
Influence of processing on the cryogenic mechanical properties of high strength high manganese stainless steel (open access)

Influence of processing on the cryogenic mechanical properties of high strength high manganese stainless steel

New high strength structural steels have been required for the large superconducting magnets that will be used for the next step test facility for fusion reactor research. The new materials must have high yield strength accompanied with better toughness and better fatigue resistance compared with the conventional nitrogen-strengthened stainless steels such as AISI 304LN and 316LN that were used for the cases of the toroidal field coils for the Large Coil Project. A number of new high manganese austenitic steels have been proposed for new cryogenic structural alloys since they can offer low cost, stable austenite and high strength.
Date: August 1, 1983
Creator: Ogawa, R. & Morris, J.W. Jr.
System: The UNT Digital Library
344 cm x 86 cm low mass vacuum window (open access)

344 cm x 86 cm low mass vacuum window

The LBL Heavy Ion Spectrometer System (HISS) superconducting magnet contains a 1 m x 3.45 m x 2 m vacuum tank in its gap. A full aperture thin window was needed to minimize background as the products of nuclear collisions move from upstream targets to downstream detectors. Six windows were built and tested in the development process. The final window's unsupported area is 3m/sup 2/ with a 25 cm inward deflection. The design consists of a .11 mm Nylon/aluminum/polypropylene laminate as a gas seal and .55 mm woven aramid fiber for strength. Total mass is 80 milligrams per cm/sup 2/. Development depended heavily on past experience and testing. Safety considerations are discussed.
Date: August 1983
Creator: Reimers, R.M.; Porter, J.; Meneghetti, J.; Wilde, S. & Miller, R.
System: The UNT Digital Library
Results obtained using the Plastic Ball (open access)

Results obtained using the Plastic Ball

Single-particle inclusive experiments, and experiments that additionally measure a few correlations like the associated multiplicity, have provided the main contribution to our present understanding of high-energy heavy-ion collisions. The results from those experiments are in overall agreement with calculations of the cascade and hydrodynamical models. In the cascade model the collision of two nuclei is simulated as a cascade of nucleon-nucleon collisions using measured N-N cross sections. The hydrodynamical model, on the other hand, describes the nuclear collision as that of two fluids and makes use of a nuclear equation of state relating thermal and compressional energy densities to pressure. The pressure field dominates the expansion phase and leads to collective flow of the reaction products in a preferred direction. The observation of such effects in inclusive experiments is not well established. Collective effects that manifest themselves in the shape of the event in phase space are expected to be seen best in complete event detectors that measure the final state as exclusively as presently possible by measuring most of the charged particles emitted in the reaction. In addition, those detectors are well suited to test macroscopic concepts such as equilibrium and temperature. Global methods like the sphericity or thrust …
Date: August 1, 1983
Creator: Ritter, H. G.; Gustafsson, H. A. & Gutbrod, H. H.
System: The UNT Digital Library
Model for superheated debris-bed quench for severe-accident containment calculations. [PWR; BWR]. CONF-831047--85 (open access)

Model for superheated debris-bed quench for severe-accident containment calculations. [PWR; BWR]. CONF-831047--85

Core meltdown accidents are being analyzed to develop an understanding of the risk associated with such postulated accidents and to evaluate the impact of possible mitigating engineering safety equipment. An integral feature of these analyses is the determination of containment building pressurization as a result of loadings imposed by the energy stored in the molten core debris. A major source of containment pressurization would result from the ex-vessel thermal interaction between molten core debris and water available beneath the reactor vessel. It has been suggested that the thermal interaction would occur in two stages: (1) the melt fall period during which the melt mixes with water, breaks up and transfers energy to the coolant, and (2) the debris bed or molten pool quench period during which the core debris rests on the concrete beneath the vessel and is cooled by an overlying pool of water. This paper is directed towards development of models to predict the thermal-hydraulic characteristics of superheated beds of solidified core debris which are cooled by water supplied by an overlying pool of water.
Date: August 1, 1983
Creator: Ginsberg, T. & Chen, J. C.
System: The UNT Digital Library
Three-dimensional equilibrium in quadrupole symmetric tandem mirrors in the paraxial limit (reduced MHD) (open access)

Three-dimensional equilibrium in quadrupole symmetric tandem mirrors in the paraxial limit (reduced MHD)

Equilibrium in quadrupole symmetric mirrors is fully three dimensional; however, because axial scale lengths are long compared with radial scale lengths (equivalently weak curvature) it is possible to reduce the complexity of the equations by expanding in the appropriate smallness parameter. Such a procedure leads to set of reduced MHD equations. The general theory will be presented, numerical results discussed, modifications due to finite Larmor radius will be added, and an analytic solution for sharp boundary pressure models will be developed.
Date: August 29, 1983
Creator: Pearlstein, L.D.
System: The UNT Digital Library
Construction and testing of the Nb/sub 3/Sn coils for the High-Field Test Facility (open access)

Construction and testing of the Nb/sub 3/Sn coils for the High-Field Test Facility

This project was undertaken: (1) to establish manufacturing capability for a high-current, cryostable Nb/sub 3/Sn conductor for the mirror fusion program; (2) to evaluate the conductor design with regard to manufacturability, windability, and cryostability; and (3) to provide a facility for testing insert coils of up to 1 m outer diameter at approximately 12 T.
Date: August 10, 1983
Creator: Zbasnik, J. P.; Scanlan, R. M.; Cornish, D. N.; Hoard, R. W.; Leber, R. L.; Johnston, J. E. et al.
System: The UNT Digital Library
Physics considerations for tandem-mirror magnet design (open access)

Physics considerations for tandem-mirror magnet design

This lecture describes the physics considerations entering the magnet design of a quadrupole-stabilized, tandem-mirror system.
Date: August 22, 1983
Creator: Baldwin, D.E.
System: The UNT Digital Library
Origin of accretionary lapilli from the Pompeii and Avellino deposits of Vesuvius (open access)

Origin of accretionary lapilli from the Pompeii and Avellino deposits of Vesuvius

Accretionary lapilli from the Pompeii and Avellino Plinian ash deposits of Vesuvius consist of centimeter-sized spheroids composed of glass, crystal, and lithic fragments of submillimeter size. The typical structure of the lapilli consists of a central massive core surrounded by concentric layers of fine ash with concentrations of larger clasts and vesicles and a thin outer layer of dust. Clasts within the lapilli larger than 125 ..mu..m are extremely rare. The median grain-size of the fine ash is about 50 ..mu..m and the size-distribution is well sorted. Most constituent particles of accretionary lapilli display blocky shapes characteristic of grains produced by phreatomagmatic hydroexplosions. We have used the scanning electron microscope (SEM) in conjunction with energy dispersive spectral analysis (EDS) to investigate the textural and chemical variation along traverses from the core to the rim of lapilli from Vesuvius.
Date: August 1983
Creator: Sheridan, M.F. & Wohletz, K.H.
System: The UNT Digital Library
Control and operation cost optimization of the HISS cryogenic system (open access)

Control and operation cost optimization of the HISS cryogenic system

The Heavy Ion Spectrometer System (HISS) relies upon superconducting coils of cryostable design to provide a maximum particle bending field of 3 tesla. A previous paper describes the cryogenic facility including helium refrigeration and gas management. This paper discusses a control strategy which has allowed full time unattended operation, along with significant nitrogen and power cost reductions. Reduction of liquid nitrogen consumption has been accomplished by making use of the sensible heat available in the cold exhaust gas. Measured nitrogen throughput agrees with calculations for sensible heat utilization of zero to 70%. Calculated consumption saving over this range is 40 liters per hour for conductive losses to the supports only. The measured throughput differential for the total system is higher.
Date: August 1, 1983
Creator: Porter, J.; Bieser, F. & Anderson, D.
System: The UNT Digital Library
TMX-U experimental results (open access)

TMX-U experimental results

This paper describes results from the Tandem Mirror Experiment-Upgrade (TMX-U). Mirror-confined electrons with 30 to 70 keV mean energy densities of 0.5 to 2.0 x 10/sup 12/ cm/sup -3/ and average betas of 3 to 5% are produced using electron-cyclotron resonant heating (ECRH). These results are consistent with an electron Fokker-Planck code. Improved ion-cyclotron microstability is observed using neutral beam injection at 47/sup 0/ to the magnetic axis, rather than at 90/sup 0/ as in the previous experiment, TMX. Strong end plugging has been produced using a combination of ECRH gyrotrons with sloshing-ion beam injection. In these low-density central cell experiments (3 x 10/sup 11/ cm/sup -3/) the axial losses (tau/sub parallel/ = 20 to 80 ms) are smaller than the nonambipolar radial losses (tau/sub perpendicular/ = 4 to 8 ms). Plugging has been achieved with a central cell density double that of the end plugs. Although no direct measurements are yet available to determine if a thermal barrier potential dip is generated, these experiments support many theoretical features of the thermal barrier concept.
Date: August 31, 1983
Creator: Simonen, T. C.; Allen, S. L.; Casper, T. A.; Clauser, J. F.; Clower, C. A.; Coensgen, F. H. et al.
System: The UNT Digital Library
Inertial effects in laser-driven ablation (open access)

Inertial effects in laser-driven ablation

The gasdynamic partial differential equations (PDE's) governing the motion of an ablatively accelerated target (rocket) contain an inertial force term that arises mathematically from acceleration of the reference frame in which the PDE's are written, and more physically from the requirement that part of the ablated mass (the deflagration wave zone) needs to be accelerated along with the unablated mass (payload). We give a simple, intuitive description of this effect, and estimate its magnitude and parametric dependences by means of approximate analytical formulas inferred from our computer hydrocode calculations. Often this inertial term is negligible, but for problems in the areas of laser fusion and laser equation of state studies we find that it can reduce the attainable hydrodynamic efficiency of acceleration and implosion by up to 25% for typical conditions.
Date: August 18, 1983
Creator: Harrach, R. J.; Szoeke, A. & Howard, W. M.
System: The UNT Digital Library
Electrical and magnetic properties of the energy-saver correction elements (open access)

Electrical and magnetic properties of the energy-saver correction elements

The lattice of the Fermi National Accelerator Laboratory's Energy Saver/Doubler contains a group of superconducting correction windings associated with each quadrupole. These are housed in an element referred to as a spool. There are 192 spools in the ring plus 12 special power spools which contain the main buss 5000 ampere power input as well as correction elements. There will be constructed and tested 290 spools, including spares of each of the eight different types. There have been 266 individual spools tested to date. The spools were tested for (a) magnetic field quality, harmonic moments, transfer constants and coil angles, (b) high voltage integrity, (c) critical transport current, and (d) cryogenic operating characteristics (i.e., heatloads, thermometry calibration checks, etc.). Data are summarized for 318 cryogenic tests and magnetic field quality of the 266 different spools, which contain 1614 correction magnet coils.
Date: August 1, 1983
Creator: Johnson, M.; McInturff, A.; Raja, R. & Mantsch, P.
System: The UNT Digital Library
Word of caution (open access)

Word of caution

It is stated that we should discard the phrase testing QCD and talk instead of studying the phenomenology of perturbative QCD. If the data lead to discrepancies with perturbative predictions plus hadronization models, we may learn something about the possible non-perturbative effects, but we will almost certainly not be led to discard QCD. Meanwhile, when the model works, we are continually reinforcing the view that our assumptions about hadronization as a soft process work well, and that the underlying hard parton process does indeed follow the behavior calculated from perturbative QCD.
Date: August 1, 1983
Creator: Quinn, H.R.
System: The UNT Digital Library
Recent progress in modeling the atmospheric dispersion of heavy gases over variable terrain using the three-dimensional conservation equations (open access)

Recent progress in modeling the atmospheric dispersion of heavy gases over variable terrain using the three-dimensional conservation equations

In this paper, a three-dimensional, conservation equation model for simulating the atmospheric dispersion of heavy gases has been briefly described; the model was successfully applied and assessed via simulating three distinctly different LNG spill experiments. These experiments involve approximately 30 m/sup 3/ LNG spills, with atmospheric conditions ranging from slightly stable to slightly unstable (ambient wind speed from about 2 m/s to 10 m/s). In general, good agreement between model predictions and field measurements was observed in all cases based on comparing, among others, the maximum concentrations as a function of downwind distance, the maximum downwind distances to the LFL, time histories of concentration at specific locations, and concentration contours on certain horizontal and crosswind surfaces. In particular, the overall results obtained in the model calculations with the simulated actual topography were shown to correlate much better with the field data in that many important features of the vapor cloud observed under the light wind conditions of Burro 8 were successfully reproduced. These include the spreading of vapor cloud in all directions (in upwind direction as well), the vortex-induced high concentration regions, the bifurcation of the NG cloud, and the deflection of the NG cloud due to sloping terrain. Through …
Date: August 1, 1983
Creator: Chan, S. T. & Ermak, D. L.
System: The UNT Digital Library
New concepts in particle acceleration (open access)

New concepts in particle acceleration

Accelerator concepts discussed include the wake-field accelerator, the two-beam accelerator, the inverse free electron laser, and the laser plasma wave accelerator. (GHT). 18 references, 12 figures.
Date: August 1, 1983
Creator: Sessler, Andrew M.
System: The UNT Digital Library
Variational-moment method for computing magnetohydrodynamic equilibria (open access)

Variational-moment method for computing magnetohydrodynamic equilibria

A fast yet accurate method to compute magnetohydrodynamic equilibria is provided by the variational-moment method, which is similar to the classical Rayleigh-Ritz-Galerkin approximation. The equilibrium solution sought is decomposed into a spectral representation. The partial differential equations describing the equilibrium are then recast into their equivalent variational form and systematically reduced to an optimum finite set of coupled ordinary differential equations. An appropriate spectral decomposition can make the series representing the solution coverge rapidly and hence substantially reduces the amount of computational time involved. The moment method was developed first to compute fixed-boundary inverse equilibria in axisymmetric toroidal geometry, and was demonstrated to be both efficient and accurate. The method since has been generalized to calculate free-boundary axisymmetric equilibria, to include toroidal plasma rotation and pressure anisotropy, and to treat three-dimensional toroidal geometry. In all these formulations, the flux surfaces are assumed to be smooth and nested so that the solutions can be decomposed in Fourier series in inverse coordinates. These recent developments and the advantages and limitations of the moment method are reviewed. The use of alternate coordinates for decomposition is discussed.
Date: August 1, 1983
Creator: Lao, L. L.
System: The UNT Digital Library
Fokker-Planck equation in mirror research (open access)

Fokker-Planck equation in mirror research

Open confinement systems based on the magnetic mirror principle depend on the maintenance of particle distributions that may deviate substantially from Maxwellian distributions. Mirror research has therefore from the beginning relied on theoretical predictions of non-equilibrium rate processes obtained from solutions to the Fokker-Planck equation. The F-P equation plays three roles: Design of experiments, creation of classical standards against which to compare experiment, and predictions concerning mirror based fusion power systems. Analytical and computational approaches to solving the F-P equation for mirror systems will be reviewed, together with results and examples that apply to specific mirror systems, such as the tandem mirror.
Date: August 11, 1983
Creator: Post, Richard F.
System: The UNT Digital Library
Unifying physical concepts of reality (open access)

Unifying physical concepts of reality

Physics may be characterized as the science of matter and energy. It anchors the two ends of the frontiers of science: the frontier of the very small and the frontier of the very large. All of the phenomena that we observe and study at the frontiers of science - all external experiences - are manifestations of matter and energy. One may, therefore, use physics to exemplify both the diversity and unity of science. This theme will be developed in two separate examples: first by sketching, very briefly, the historical origins of frontiers of the very small and very large and the converging unity of these two frontiers; and then by describing certain unifying concepts that play a central role in physics and provide a framework for relating developments in different sciences.
Date: August 1, 1983
Creator: Gilbert, T. L.
System: The UNT Digital Library
Design and construction of the vacuum vessel for the tandem Mirror Fusion Test Facility (open access)

Design and construction of the vacuum vessel for the tandem Mirror Fusion Test Facility

We have designed the MFTF-B vacuum vessel both to maintain the required vacuum environment and to structurally support the 42 superconducting magnets plus auxiliary internal and external equipment. The design calculations were greatly aided by computer models, which also speeded our redesign effort when the machine configuration was changed to the Axicelll MFTF-B this past year. Our field construction and erection effort should meet the July 1984 completion date for the vacuum vessel.
Date: August 12, 1983
Creator: Gerich, J.W.
System: The UNT Digital Library
Initial operation of the LBL heavy ion RFQ (open access)

Initial operation of the LBL heavy ion RFQ

The LBL heavy ion RFQ accelerator, a 200 MHz structure that accelerates an ion with q/A greater than or equal to 1/7 from 8.4 to 200 keV/n, has now passed all its acceptance tests. This machine is unique in several respects: it uses coupling rings between vanes to stablize the azimuthal field distribution, it incorporates a vane mounting system that simplifies vane alignment, it uses no end tuners or power distribution manifold, and it needs only one rf feed loop. The beam performance of this machine is reported in this paper.
Date: August 1, 1983
Creator: Staples, J.; Gough, R.; Schneider, H. & Zajec, E.
System: The UNT Digital Library
Vane-coupling rings simplify tuning of the LBL RFQ accelerator (open access)

Vane-coupling rings simplify tuning of the LBL RFQ accelerator

A new heavy ion RFQ accelerator has been commissioned as part of a Bevalac injector upgrade project. This RFQ is the first four vane type to incorporate vane coupling rings (VCR's) as part of the structure. This paper reports on the simplified tune up procedure made possible by the use of VCR's including field flattening, end tuning, and frequency adjustment. Also included is a discussion of high power performance including conditioning.
Date: August 1, 1983
Creator: Lancaster, H.; Gough, R.; Howard, D. & Schneider, H.R.
System: The UNT Digital Library
Spallation and 14-MeV neutron irradiation of stabilized NbTi superconductors (open access)

Spallation and 14-MeV neutron irradiation of stabilized NbTi superconductors

The results on 5 K irradiation available so far may be summarized as follows. (1) Increases of j/sub c/ following neutron irradiation occur only in conductors which are far from the optimal metallurgical treatments. (2) The changes of j/sub c/ following neutron irradiation and a thermal cycle to room temperature are small and in most cases comparable to the results obtained after 77 K irradiation. (3) The data available so far indicate that the degradation of j/sub c/ at 8 T is larger by about 5 to 10% than the corresponding changes at 5 T at a neutron fluence of 1.3 x 10/sup 22/ m/sup -2/ (E > 0.1 MeV). (4) The increase of Cu-resistivity is significant even after a thermal cycle to room temperature and requires design changes for a stable magnet operation.
Date: August 1, 1983
Creator: Hahn, P.; Brown, B. S.; Weber, H. W. & Guinan, M. W.
System: The UNT Digital Library