Mirror theory applied to toroidal systems (open access)

Mirror theory applied to toroidal systems

Central features of a mirror plasma are strong departures from Maxwellian distribution functions, ambipolar potentials and densities which vary along a field line, and losses, and the mirror field itself. To examine these features, mirror theorists have developed analytical and numerical techniques to solve the Fokker-Planck equation, evaluate the potentials consistent with the resulting distribution functions, and assess the microstability of these distributions. Various combinations of mirror-plasma fetures are present and important in toroidal plasmas as well, particularly in the edge region and in plasmas with strong r.f. heating. In this paper we survey problems in toroidal plasmas where mirror theory and computational techniques are applicable, and discuss in more detail three specific examples: calculation of the toroidal generalization of the Spitzer-Haerm distribution function (from which trapped-particle effects on current drive can be calculated), evaluation of the nonuniform potential and density set up by pulsed electron-cyclotron heating, and calculation of steady-state distribution functions in the presence of strong r.f. heating and collisions. 37 refs., 3 figs.
Date: August 25, 1987
Creator: Cohen, R.H.
Object Type: Article
System: The UNT Digital Library
Finite element stress analysis of D0 test beam transporter mainframe assembly (open access)

Finite element stress analysis of D0 test beam transporter mainframe assembly

The D0 test beam transporter mainframe assembly is a structural frame lying in a horizontal plane and designed to support and orient the D0 test liquid argon calorimeter properly in the test beam. Azimuthal adjustment is provided by a turntable with a mean radius of 64 inches, supported on a pressurized oil bearing. Angular positioning is achieved by an hydraulic actuator attached to the turntable which places force against an arm on the calorimeter vessel, causing it to rotate. Vertical positioning is adjusted by jacks at four corners of the platform. Preliminary design calculations were based on simplifying and conservative assumptions which rendered the problem statically determinate. The purpose of this analysis is to provide more precise information on stress and deflection by including redundancies and structural detail. 2 figs., 1 tab.
Date: September 25, 1987
Creator: Wands, B.
Object Type: Report
System: The UNT Digital Library
Spatially resolved x-ray laser spectra and demonstration of gain in nickel-like systems (open access)

Spatially resolved x-ray laser spectra and demonstration of gain in nickel-like systems

A recent series of experiments have provided spatially resolved near field images of several candidate x-ray lasing transition in neon-like, nickel-like, and hydrogen-like ions from laser-produced plasmas. From these time-gated, spatially, and spectrally resolved measurements the source size for the J = 0 - 1 and the J = 2 - 1 transitions in Ne-like selenium have been determined. Source regions as small as 50 ..mu..m have been observed on transitions with gain-length products >9. In addition, we have obtained the first experimental evidence for the amplification of spontaneous emission in the nickel-like ions of europium and ytterbium. Gains of order 1 cm/sup -1/ and gain-length products of up to 3.8 are observed on the J = 0 - 1, 4d-4p transitions in Eu + 35 at 65.26 and 71.00 A. Analogous transitions in Yb = +42 have been identified and some evidence for ASE has been observed. 7 refs., 11 figs.
Date: September 25, 1987
Creator: Whelan, D. A.; Keane, C. J.; MacGowan, B. J.; Matthews, D. L.; Trebes, J. E. & Eckart, M. J.
Object Type: Article
System: The UNT Digital Library
Automated microscopy methods for measuring pyritic sulfur content of coal and determining degree of liberation of pyrite in coal: Final report (open access)

Automated microscopy methods for measuring pyritic sulfur content of coal and determining degree of liberation of pyrite in coal: Final report

The objective of this project is to develop an automated procedure, to be implemented in an IBAS image analyzer, to determine size, shape and degree of liberation of pyrite particles in a coal matrix. This procedure is to work in real time conditions and with minimal intervention from the operator. Our approach is to create from the original microscopic image a three level image with the following components: epoxy, coal macerals and pyrite to simplify the calculations. Enhancing the original image by histogram scaling and median filtering, we segment it and form the three level image. After the boundaries of the pyrite particles are defined, we mask the surroundings of the particle to estimate the degree of liberation. The percentage of epoxy included in the mask is defined as the degree of liberation of the particle. Size and shape factor values are simultaneously calculated for each of the analyzed particles. These particles are classified according to their maximum diameter, shape factor and degree of liberation by the program. 6 refs., 18 figs.
Date: July 25, 1987
Creator: Chaparro, L.F.
Object Type: Report
System: The UNT Digital Library
Mirror theory applied to toroidal systems (open access)

Mirror theory applied to toroidal systems

Central features of a mirror plasma are strong departures from Maxwellian distribution functions, ambipolar potentials and densities which vary along a field line, end losses, and the mirror field itself. To examine these features, mirror theorists have developed analytical and numerical techniques to solve the Fokker-Planck equation, evaluate the potentials consistent with the resulting distribution functions, and assess the microstability of these distributions. Various combinations of mirror-plasma features are present and important in toroidal plasmas as well, particularly in the edge region and in plasmas with strong rf heating. In this paper we survey problems in toroidal plasmas where mirror theory and computational techniques are applicable, and discuss in more detail three specific examples: calculation of the toroidal generalization of the Spitzer-Haerm distribution function (from which trapped-particle effects on current drive can be calculated), evaluation of the nonuniform potential and density set up by pulsed electron-cyclotron heating, and calculation of steady-state distribution functions in the presence of strong rf heating and collisions. 37 refs.
Date: August 25, 1987
Creator: Cohen, R.H.
Object Type: Article
System: The UNT Digital Library
Multidimensional modeling of convective heat transfer with application to IC (internal combustion) engines (open access)

Multidimensional modeling of convective heat transfer with application to IC (internal combustion) engines

The objective of this project is to develop a more comprehensive understanding of the convective heat transfer process in complex, unsteady turbulent reacting flows, typical of those which occur in internal combustion engines. The specific area of research will be the representation of heat transfer in detailed multi-dimensional Navier-Stokes models, and modeling of turbulent transport mechanisms. The detailed tasks will include a review of relevant prior work. Based on this review, and original work done under this contract, several modeling approaches will be formulated and further studied and tested. The tests will be carried out on flow cases which have relevance to engine flows, and for which reliable experimental data exist. Such data will be sought and identified. The analytical studies will lead to the determination of the best modeling approaches to be used for heat transfer simulation in internal combustion engines. Following that, a detailed study will be carried out of spatial and temporal heat flux distribution in a representative engine. This will be complemented by a parametric study of engine heat transfer dependence on intake flow details, combustion chamber geometry, engine speed and engine load.
Date: September 25, 1987
Creator: Jennings, M.J. & Morel, T.
Object Type: Report
System: The UNT Digital Library
Soft x-ray generation by the Cherenkov effect (open access)

Soft x-ray generation by the Cherenkov effect

The Cherenkov effect may be used to generate coherent soft x rays by taking advantage of the dielectric constants of materials in the neighborhood of atomic resonances. The Cherenkov effect usually is not possible for x rays because the refractive index is less than one for most x-ray frequencies. However, for narrow frequency bands near atomic resonances, the refractive index can exceed unity with values large enough to generate coherent x rays with efficiencies higher than any other electron-driven technique. The basic physics of the process is discussed and is used to make rough estimates of photon production efficiencies. An exact theoretical description of Cherenkov production in thin foils is used together with recently-measured refractive indices to calculate the emission distributions of 100 eV photons from thin silicon foils. These distributions are found to be roughly consistent with the simple estimates. In addition, unusual behavior by the distributions suggests a technique that can be used to increase dramatically the peak angular intensities. 15 refs., 10 figs.
Date: February 25, 1987
Creator: Moran, M. J. & Chang, B.
Object Type: Article
System: The UNT Digital Library
Anomalies in near-threshold photoabsorption: Resonances, ''white-lines'' and other enhancements (open access)

Anomalies in near-threshold photoabsorption: Resonances, ''white-lines'' and other enhancements

Synchrotron measurements of near-threshold and broad-range (80 to 1000 eV) absolute photoabsorption cross sections were taken at Brookhaven using the plane grating monochromator at the VuV storage ring beam line U14A of the NSLS facility. Transmission data for well characterized multilayer foils of C, Ti, Cr, Ni, Cu, Th and U provided absolute cross sections with 10% overall uncertainties and better than 2 eV resolution.
Date: February 25, 1987
Creator: Del Grande, N.K.
Object Type: Article
System: The UNT Digital Library
Review of the Advanced Toroidal Facility program (open access)

Review of the Advanced Toroidal Facility program

This report summarizes the history and design goals of the Advanced Toroidal Facility (ATF). The ATF is nearing completion at ORNL with device completion expected in May 1987 and first useful plasma operation in June/July 1987. ATF is a moderate-aspect-ratio torsatron, the world's largest stellarator facility with R = 2.1 m, ..cap alpha.. bar = 0.3 m and B = 2 T (5-s pulse) or 1 T (steady-state capability). It has been specifically designed to support the US tokamak program by studying important toroidal confinement issues in a similar magnetic geometry that allows external control of the magnetic configuration properties and their radial profiles: transform, shear, well depth, shaping, axis topology, etc. ATF will operate in a current-free model which allows separation of current-driven and pressure-driven plasma behavior. It also complements the world stellarator program in its magnetic configuration (between Heliotron-E and W VII-AS) and its capabilities (large size, good access, steady state capability, second stability access, etc.). For both roles ATF will require high-power long-pulse heating to carry out its physics goals since the high power NBI pulse is limited to 0.3 s. The ATF program focuses on demonstrating the principles of high-beta, steady-state operation in toroidal geometry through …
Date: February 25, 1987
Creator: Lyon, J.F. & Murakami, M.
Object Type: Article
System: The UNT Digital Library
Assessment of the proposed decontamination and waste treatment facility at LLNL (open access)

Assessment of the proposed decontamination and waste treatment facility at LLNL

To provide a centralized decontamination and waste treatment facility (DWTF) at LLNL, the construction of a new installation has been planned. Objectives for this new facility were to replace obsolete, structurally and environmentally sub-marginal liquid and solid waste process facilities and decontamination facility and to bring these facilities into compliance with existing federal, state and local regulations as well as DOE orders. In a previous study, SAIC conducted a preliminary review and evaluation of existing facilities at LLNL and cost effectiveness of the proposed DWTF. This document reports on a detailed review of specific aspects of the proposed DWTF.
Date: March 25, 1987
Creator: Cohen, J.J.
Object Type: Report
System: The UNT Digital Library
Models of optical and soft x-ray spectra in AM Her stars (open access)

Models of optical and soft x-ray spectra in AM Her stars

The AM Her systems are widely believed to be cataclysmic variable systems in which the white dwarf has a magnetic field strong enough to lock the white dwarf to the companion star. The magnetic field channels the accretion flow to the magnetic polar caps of the white dwarf where the gas passes through a strong shock and the accretion energy is released. The continuum spectra of the AM Her systems have three major components: the ir/optical component, the EUV/soft x-ray component, and the hard x-ray component. Models of the AM Her systems generally agree that the hard x-rays are free-free radiation emitted by the hot postshock gas and that the optical component is electron cyclotron emission from the postshock gas. The soft x-ray component is less well understood, primarily because it is very soft (temperature less than 100 eV) and thus is very difficult to measure accurately with current instruments. Models agree that some soft x-ray emission will arise from hard x-rays and cyclotron radiation that is absorbed at the stellar surface and re-radiated, but other sources of soft x-rays have also been suggested. Thus it is important to develop models for the soft x-ray spectrum. This paper presents some …
Date: May 25, 1987
Creator: Langer, S.H.
Object Type: Article
System: The UNT Digital Library
Radioiodine in kelp from western Australia (open access)

Radioiodine in kelp from western Australia

As part of a program to survey low levels of radioactivity in the marine environment of the southern hemisphere, we have studied the distribution and uptake of /sup 131/I found in the subtidal kelp Ecklonia radiata, on the west coast of Australia. Concentrations of 5 to 75 fCi/g of /sup 131/I exist in this species over a considerable distance along the coast. We have characterized the principal source of the /sup 131/I and found a general temporal correlation between the amount of radioiodine discharged from sewer outfalls and its concentration in kelp. Transplant experiments have enabled us to estimate uptake and depuration rates, and our results are consistent with laboratory measurements made by others.
Date: March 25, 1987
Creator: Marsh, K.V.; Buddemeier, R.W.; Wood, W. & Smith, C.
Object Type: Article
System: The UNT Digital Library
The potential for reducing the cost of a heavy ion accelerator for ICF: Final report (open access)

The potential for reducing the cost of a heavy ion accelerator for ICF: Final report

This study was initiated to identify the high leverage areas for reducing the cost of a 10 MJ heavy ion beam driver for a high gain target development facility. Our efforts to innovate to reach affordable cost have been mostly successful, in that it looks like the $500 M range may indeed be possible. We conclude that heavy ion beams do have substantial promise for an inertial fusion driver. However, the pace of R and D would have to be substantially increased to realize this promise on a timescale necessary for a High Gain Test Facility.
Date: February 25, 1987
Creator: Monsler, M. J.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 12, Number 64, Pages 2824-2874, August 25, 1987 (open access)

Texas Register, Volume 12, Number 64, Pages 2824-2874, August 25, 1987

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: August 25, 1987
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 12, Number 72, Pages 3339-3400, September 25, 1987 (open access)

Texas Register, Volume 12, Number 72, Pages 3339-3400, September 25, 1987

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: September 25, 1987
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 12, Number 96, Pages 4865-4930, December 25, 1987 (open access)

Texas Register, Volume 12, Number 96, Pages 4865-4930, December 25, 1987

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: December 25, 1987
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Attorney General Opinion: JM-637 (open access)

Texas Attorney General Opinion: JM-637

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Olbigation of a limited hospital authority to provide services under the Indigent Health Care and Treatment Act, article 4438f, V.T.C.S.
Date: February 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-638 (open access)

Texas Attorney General Opinion: JM-638

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether local school districts are required to furnish names and addresses of parents of blind students to the Texas School for the Blind
Date: February 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-655 (open access)

Texas Attorney General Opinion: JM-655

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether a county that assesses and collects taxes for a community college district may add a 2% fee
Date: March 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-708 (open access)

Texas Attorney General Opinion: JM-708

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Supervisory control of a district court over a county commissioners court under article V, section 8, of the Texas Constitution
Date: May 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-727 (open access)

Texas Attorney General Opinion: JM-727

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Duty of district clerk to file and docket improperly tendered documents
Date: June 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-728 (open access)

Texas Attorney General Opinion: JM-728

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether a county may abandon a neighborhood road without replacing it
Date: June 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-774 (open access)

Texas Attorney General Opinion: JM-774

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Whether the Veterans Land Board may impose a fee for delivery of a paid-in-full deed to a purchaser under the Veterans Land Program
Date: August 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-796 (open access)

Texas Attorney General Opinion: JM-796

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Authority of the State Board of Dental Examiners to reinstate a license that has been cancelled because of failure to comply with statutory requirements
Date: September 25, 1987
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History