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Computing tools for accelerator design (open access)

Computing tools for accelerator design

An algorithm has been developed that calculates and obtains information about nonlinear contributions in accelerators. The comparison of the results obtained from this program ''NONLIN'' and HARMON is discussed and illustrated for the SSC-CDR clustered lattices.
Date: June 1, 1986
Creator: Parsa, Z.
Object Type: Report
System: The UNT Digital Library
Probing nuclear matter with dileptons (open access)

Probing nuclear matter with dileptons

Dileptons are shown to be of interest in helping probe extreme conditions of temperature and density in nuclear matter. The current state of experimental knowledge about dileptons is briefly described, and their use in upcoming experiments with light ions at CERN SPS are reviewed, including possible signatures of quark matter formation. Use of dileptons in an upcoming experiment with a new spectrometer at Berkeley is also discussed. This experiment will probe the nuclear matter equation of state at high temperature and density. 16 refs., 8 figs. (LEW)
Date: June 1, 1986
Creator: Schroeder, L. S.
Object Type: Article
System: The UNT Digital Library
Lack of immediate effects from the 1979-80 Imperial and Victoria earthquakes on the exploited Cerro Prieto geothermal reservoir (open access)

Lack of immediate effects from the 1979-80 Imperial and Victoria earthquakes on the exploited Cerro Prieto geothermal reservoir

In 1979-1980 two large earthquakes of local magnitude (M/sub L/) greater than 6.0 occurred near the Cerro Prieto geothermal field. It has been suggested that related to these seismic events there was an abrupt temperature increase in the wells completed in the shallow (alpha) reservoir. A careful study of the geochemistry of the produced fluids, as well as a cursory reservoir engineering analysis, cannot confirm either the data or the hypothesis of a massive influx of hot water into the system related to those events. Our study shows that the cold water recharge of the alpha reservoir in response to the production-induced drawdown continued, unaffected by the two earthquakes.
Date: June 1, 1986
Creator: Truesdell, A.H. & Lippmann, M.J.
Object Type: Article
System: The UNT Digital Library
Numerical studies of gravity effects in two-phase reservoirs (open access)

Numerical studies of gravity effects in two-phase reservoirs

Numerical studies are performed to investigate the effects of localized feed zones on the pressure transients in two-phase reservoirs. It is shown that gravity effects can significantly affect the pressure transients, because of the large difference in the density of liquid water and vapor. Pressure transients for shallow and deep feed zones and the resulting fluid flow patterns are discussed.
Date: June 1, 1986
Creator: Bodvarsson, G.S. & Cox, B.L.
Object Type: Article
System: The UNT Digital Library
Personal extrapolation of CDF test beam use to the SSC (open access)

Personal extrapolation of CDF test beam use to the SSC

The author's personal experience in test beam usage at CDF is used to predict SSC needs at the point of turn-on. It is concluded that the test beam demand will reflect the scale of effort involved in SSC detectors rather than the total number of them. Provision for later expansion is recommended. It is also recommended that the test beam facilities, as well as detector electronics, should reflect the available dynamic range; particularly, a single high energy beam derived from the SSC could be shared by several groups. (LEW)
Date: June 23, 1986
Creator: Nodulman, L.
Object Type: Article
System: The UNT Digital Library
Indoor air quality measurements in 38 Pacific Northwest commercial buildings (open access)

Indoor air quality measurements in 38 Pacific Northwest commercial buildings

A Bonneville Power Administration-funded study monitored ventilation rates and a variety of indoor air pollutants in 38 Pacific Northwest commercial buildings. The buildings ranged in age from 6 months to 90 years, in size from 864 to 34,280 m/sup 2/, and occupancy from 25 to 2500 people. Building average formaldehyde (HCHO) concentrations were below the 20 ppB detection limit in 48% of the buildings. Nitrogen dioxide (NO/sub 2/) concentration averages ranged from 5 ppB to 43 ppB and were lower than outdoor concentrations in 8 of 13 buildings. At only one site, an elementary school classroom, did carbon dioxide (CO/sub 2/) exceed 1000 ppM. Radon (Rn) levels were elevated in one building with an average concentration of 7.4 pCiL/sup -1/. Respirable particles (RSP) concentrations in smoking areas in 32 buildings had a geometric mean of 44 ..mu..g m/sup -3/ and ranged up to 308 ..mu..g m/sup -3/ at one site. In non-smoking areas the geometric mean RSP was 15 ..mu..g m/sup -3/. Outside air ventilation rates did not appear to be the single dominant parameter in determining indoor pollutant concentrations. Measured pollutant concentrations in 2 ''complaint'' buildings were below accepted guidelines. The cause of the complaints was not identified.
Date: June 1, 1986
Creator: Turk, B. H.; Brown, J. T.; Geisling-Sobotka, K.; Froehlich, D. A.; Grimsrud, D. T.; Harrison, J. et al.
Object Type: Article
System: The UNT Digital Library
Laser neutralization (open access)

Laser neutralization

Laser photodetachment of the excess electron to neutralize relativistic ions offers many advantages over the more conventional collisional methods using gases or thin foils as the neutralization agents. Probably the two most important advantages of laser photodetachment are the generation of a compact and low divergence beam, and the production of intense neutral beams at very high efficiency (approximately 90%). The high intensities or high current densities of the neutral beam result from the fixed maximum divergence that can be added to the beam by photodetachment of the charge using laser intensity of fixed wavelength and incident angle. The high neutralization efficiency is possible because there is no theoretical maximum to the neutralization efficiency, although higher efficiencies require higher laser powers and, therefore, costs. Additional advantages include focusability of the laser light onto the ion beam to maximize its efficacy. There certainly is no residual gas left in the particle beam path as is typical with gas neutralizers. The photodetachment process leaves the neutral atoms in the ground state so there is no excited state fluorescence to interfere with the subsequent beam sensing. Finally, since the beams to be neutralized are very high powered, for a large range of neutralization …
Date: June 17, 1986
Creator: Peterson, O.G.
Object Type: Report
System: The UNT Digital Library
Is a 4-train support ''always'' more reliable than a 2-train support (open access)

Is a 4-train support ''always'' more reliable than a 2-train support

Once the gross features of a frontline fluid system have been defined, one must consider what support system configuration will provide the best overall system performance. This paper considers different dc bus configurations for a given emergency feedwater system. Results indicate that a four-train support system (i.e., 4 dc buses) gives a lower system unavailability for transients, but a higher system unavailability for Anticipated Transients Without Scram (ATWS), than a two-train support system (i.e., two dc buses). This serves to illustrate that more trains do not necessarily provide higher reliability, and that a configuration choice which is better for one mission success criterion may be worse for another. Because of the small characteristic unreliability of dc buses, the numerical comparisons made here are not dramatic, but the underlying topological point is nevertheless broadly applicable. The EFWS selected in this study consists of two turbine-driven pumps, and two motor-driven pumps, with associated piping, instruments, and valves. There are two divisions of EFWS, each division including one turbine-driven pump train, and one motor-driven pump train with a crosstie that can provide an alternate flow path in case one train is not available. Each of the motor-driven pumps has one ac power bus …
Date: June 1, 1986
Creator: Guey, C.N.; Arrieta, L. & Youngblood, R.
Object Type: Article
System: The UNT Digital Library
The Two-beam accelerator (open access)

The Two-beam accelerator

The Two-Beam Accelerator (TBA) consists of a long high-gradient accelerator structure (HGS) adjacent to an equal-length Free Electron Laser (FEL). In the FEL, a beam propagates through a long series of undulators. At regular intervals, waveguides couple microwave power out of the FEL into the HGS. To replenish energy given up by the FEL beam to the microwave field, induction accelerator units are placed periodically along the length of the FEL. In this manner it is expected to achieve gradients of more than 250 MV/m and thus have a serious option for a 1 TeV x 1 TeV linear collider. The state of present theoretical understanding of the TBA is presented with particular emphasis upon operation of the ''steady-state'' FEL, phase and amplitude control of the rf wave, and suppression of sideband instabilities. Experimental work has focused upon the development of a suitable HGS and the testing of this structure using the Electron Laser Facility (ELF). Description is given of a first test at ELF with a seven-cell 2..pi../3 mode structure which without preconditioning and with a not-very-good vacuum nevertheless at 35 GHz yielded an average accelerating gradient of 180 MV/m.
Date: June 1, 1986
Creator: Sessler, A. M. & Hopkins, D. B.
Object Type: Article
System: The UNT Digital Library
Change in the particle action due to magnetic field perturbations in the SSC (open access)

Change in the particle action due to magnetic field perturbations in the SSC

The motion of a particle in the linear lattice of the SSC is stable, that is, the Courant-Synder invariant (W/sub 0/) remains exactly constant and the betatron phase (psi) increase by (2..pi nu..) for every revolution around the circumference. However, when magnetic field perturbations are present around the ring, this mode of describing the motion is no longer valid. One can then still speak of action-angle variables (W,phi) which in the limit of zero perturbation reduce to the linear betatron invariant and the betatron phase. The change in phase (phi-psi) is then directly related to the perturbed betatron tune, while the change in action (W-W/sub 0/) is closely related to the idea of ''smear'' or ''change in the linear invariant.'' In this paper, consistent with these concepts, we develop the theory of particle motion for field perturbations around the machine. We confine ourselves to motion in one plane only and treat the field perturbations to first order in their strength. Based on the assumed random multipoles in the SSC dipole magnets, we then obtain an estimate of the ''linear aperture'' of the machine.
Date: June 1, 1986
Creator: Herrera, J.C.
Object Type: Article
System: The UNT Digital Library
Electron dynamics with radiation and nonlinear wigglers (open access)

Electron dynamics with radiation and nonlinear wigglers

The physics of electron motion in storage rings is described by supplementing the Hamiltonian equations of motion with fluctuating radiation reaction forces to describe the effects of synchrotron radiation. This leads to a description of radiation damping and quantum diffusion in single-particle phase-space by means of Fokker-Planck equations. For practical purposes, most storage rings remain in the regime of linear damping and diffusion; this is discussed in some detail with examples, concentrating on longitudinal phase space. However special devices such as nonlinear wigglers may permit the new generation of very large rings to go beyond this into regimes of nonlinear damping. It is shown how a special combined-function wiggler can be used to modify the energy distribution and current profile of electron bunches.
Date: June 1, 1986
Creator: Jowett, J.M.
Object Type: Article
System: The UNT Digital Library
Inertial fusion research at Lawrence Livermore National Laboratory: program status and future applications (open access)

Inertial fusion research at Lawrence Livermore National Laboratory: program status and future applications

The objectives of the Lawrence Livermore National Laboratory (LLNL) Laser Fusion Program are to understand and develop the science and technology required to utilize inertial confinement fusion (ICF) for both military and commercial applications. The results of recent experiments are described. We point out the progress in our laser studies, where we continue to develop and test the concepts, components, and materials for present and future laser systems. While there are many potential commercial applications of ICF, we limit our discussions to electric power production.
Date: June 5, 1986
Creator: Meier, W. R. & Hogan, W. J.
Object Type: Article
System: The UNT Digital Library
Probing QCD in low energy anti pp collisions (open access)

Probing QCD in low energy anti pp collisions

A number of exclusive and inclusive antiproton reactions are discussed which could provide useful constraints or test novel features of quantum chromodynamics in the intermediate momentum transfer domain involving both perturbative and non-perturbative dynamics. High momentum transfer reactions are briefly reviewed. Inclusive antiproton reactions and the QCD critical length, QCD predictions for proton-antiproton exclusive processes, and studies of the Compton amplitude in proton-antiproton annihilation are covered. Testing hadron helicity conservation in heavy quark resonance is discussed. Also covered are heavy hadron pair production in proton-antiproton exclusive interactions, exclusive nuclear reactions, and quasi-exclusive nuclear processes. (LEW)
Date: June 1, 1986
Creator: Brodsky, Stanley J.
Object Type: Article
System: The UNT Digital Library
Comparison of the Relative Importance of Helium and Vacancy Accumulation in Void Nucleation (open access)

Comparison of the Relative Importance of Helium and Vacancy Accumulation in Void Nucleation

Void nucleation in irradiated austenitic stainless steels generally requires the presence of either residual or transmutant gases. Classical nucleation rates are much too low to account for the number of voids observed at temperatures greater than about 450/sup 0/C. An alternate path is generally believed to be responsible for void formation; viz. the growth of gas-stabilized bubbles until they reach a critical size beyond which further gas accumulation is not required to promote growth. Two limiting paths can be envisioned for void nucleation on a population of sub-critical helium/vacancy clusters; one is limited to growth by helium accumulation along and the other to growth by stochastic fluctuations in the vacancy accumulation. As bubbles approach the critical size, stochastic processes could begin to contribute to the void nucleation rate. A comparison is made of nucleation rates along these two limiting paths as a function of the gas content of the clusters.
Date: June 1, 1986
Creator: Stoller, R. E. & Odette, G. R.
Object Type: Article
System: The UNT Digital Library
Construction of relativistic quantum theory: a progress report (open access)

Construction of relativistic quantum theory: a progress report

We construct the particulate states of quantum physics using a recursive computer program that incorporates non-determinism by means of locally arbitrary choices. Quantum numbers and coupling constants arise from the construction via the unique 4-level combinatorial hierarchy. The construction defines indivisible quantum events with the requisite supraluminal correlations, yet does not allow supraluminal communication. Measurement criteria incorporate c, h-bar and m/sub p/ or (not ''and'') G, connected to laboratory events via finite particle number scattering theory and the counter paradigm. The resulting theory is discrete throughout, contains no infinities, and, as far as we have developed it, is in agreement with quantum mechanical and cosmological fact.
Date: June 1, 1986
Creator: Noyes, H. Pierre
Object Type: Article
System: The UNT Digital Library
Grazing incidence synchrotron radiation optics: correlation of performance with metrology (open access)

Grazing incidence synchrotron radiation optics: correlation of performance with metrology

Image distortions produced by a cylinder mirror at the National Synchrotron Light Source are compared with performance predictions based on measurements of surface slope errors in the millimeter spatial period regime made with an optical surface profiler.
Date: June 1, 1986
Creator: Takacs, P. Z.; Hewitt, R. C. & Church, E. L.
Object Type: Article
System: The UNT Digital Library
Spectral characteristics and power distribution from insertion devices on a 6 to 7 GeV storage ring (open access)

Spectral characteristics and power distribution from insertion devices on a 6 to 7 GeV storage ring

Two different types of insertion devices - undulators and wigglers - are described and compared. Each provides a periodic magnetic field that alters polarity, but whereas the spectral distribution from a wiggler is continuous and wide, the radiation of an undulator has spectrally narrow and discrete peaks. The distinction is determined by the deflection parameter. The energy spread in undulator peaks is calculated. Insertion device magnets and gap are discussed. Undulator tunability from gap variation is considered on a 6-GeV lattice and on a 7-GeV lattice. Also discussed is the angular distribution of power and the polarization from various sources. (LEW)
Date: June 1, 1986
Creator: Shenoy, G. K. & Viccaro, P. J.
Object Type: Article
System: The UNT Digital Library
Gauge invariant actions for string models (open access)

Gauge invariant actions for string models

String models of unified interactions are elegant sets of Feynman rules for the scattering of gravitons, gauge bosons, and a host of massive excitations. The purpose of these lectures is to describe the progress towards a nonperturbative formulation of the theory. Such a formulation should make the geometrical meaning of string theory manifest and explain the many ''miracles'' exhibited by the string Feynman rules. There are some new results on gauge invariant observables, on the cosmological constant, and on the symmetries of interacting string field theory. 49 refs.
Date: June 1, 1986
Creator: Banks, T.
Object Type: Article
System: The UNT Digital Library
Transport of intense ion beams. [HIBALL II] (open access)

Transport of intense ion beams. [HIBALL II]

The maximum transportable current for an ion beam is determined by considerations of focal strength, space charge equilibrium and stability, structural practically and emittance. These factors are described within the context of a heavy ion driver for Inertial Confinement Fusion. Recent supporting results from particle-in-cell simulations and transport experiments will be described.
Date: June 1, 1986
Creator: Lee, Edward P.
Object Type: Article
System: The UNT Digital Library
KMC unitarity and K/sup +/ yields. pi. /sup +/. nu. anti. nu (open access)

KMC unitarity and K/sup +/ yields. pi. /sup +/. nu. anti. nu

Experimental constraints on the Kobayashi-MaskawaCabibbo (KMC) matrix are surveyed and shown to provide a test of the standard model at the level of its O (..cap alpha..) radioactive corrections. The three generation prediction BR (K/sup +/ ..-->.. ..pi../sup +/..nu..) approx. = (0.35 approx. 3) x 10/sup 10/ is reviewed and the potential for enhancement up to approx. = 3 x 10/sup -9/ due to the fourth generation mixing is described. 19 refs.
Date: June 1, 1986
Creator: Marciano, William J.
Object Type: Article
System: The UNT Digital Library
Review of the classical nova outburst (open access)

Review of the classical nova outburst

Observational studies have not only identified a new class of novae but theoretical simulations of this class have been found to be in excellent agreement with the observations. This new class consists of outbursts occurring on ONeMg white dwarfs in close binar systems in contrast to the other outbursts which are occurring on CO white dwarfs. We also review the effects of the ..beta../sup +/-unstable nuclei and show how their presence has a major effect on the evolution. 77 refs.
Date: June 1, 1986
Creator: Starrfield, S. & Sparks, W. M.
Object Type: Article
System: The UNT Digital Library
Development of a continuous duty cryopump (open access)

Development of a continuous duty cryopump

The continuous output of large quantities of gases at low pressure from fusion reactors, principally helium and hydrogen isotopes, dictates the need for a high speed pumping system that operates continuously, efficiently, and automatically. A liquid helium-cooled cryopump operated by a microprocessor controller can meet these requirements. The prototype system described herein features a single cryopump with three distinct pumping units: two units for pumping the vacuum chamber arranged so that one unit is closed for regenerating while the other is pumping the chamber (100% redundancy); and a collector pump, which is a high speed cryopump for receiving the regenerated gas. The unit pumps deuterium but can be changed readily to a sorption pump for helium service.
Date: June 1, 1986
Creator: Sedgley, D. W.; Batger, T. H. & Call, W. R.
Object Type: Report
System: The UNT Digital Library
Computerized data acquisition system for production, injection and interference tests (open access)

Computerized data acquisition system for production, injection and interference tests

A computer-based system for collecting, processing, and analyzing pressure transient data has been developed. Primary components include downhole pressure sensors, linedrivers, a micro-computer, data storage disk, scanner, frequency counter, digital voltmeter, power supply, graphics plotter, and printer. In-field data processing and analysis greatly aid in handling the large volume of data that are collected during pressure transients tests, particularly the multiwell interference tests that are so important for characterizing and assessing geothermal reservoirs. In-field data processing provides the field engineer, on a real-time basis, with the information needed to make decisions regarding test parameters and duration. The system has been used on numerous occasions and has proved itself to be reliable under the harsh operating conditions that are usually encountered in the field. This paper describes the advantages of using this type of system for collecting data, the components and configuration of the system, and the software programs used to collect and process the data. Finally, two field applications are presented.
Date: June 1, 1986
Creator: Benson, S.M.
Object Type: Article
System: The UNT Digital Library
Master oscillator stability requirements considerations (open access)

Master oscillator stability requirements considerations

This note attempts to point out some ideas about the required stability of the 476 MHz master oscillator, assuming that the phase noise of the oscillator is the only source of noise in the accelerator system.
Date: June 24, 1986
Creator: Schwarz, H. & Vancraeynest, J.
Object Type: Report
System: The UNT Digital Library