Remarks on the clump theory (open access)

Remarks on the clump theory

Further details are provided of a soon-to-be published dialog (Phys. Fluids 29 (July, 1986)) which discussed the role of the small scales in fluid clump theory. It is argued that the approximation of the clump lifetime which is compatible with exponentially rapid separation of adjacent orbits is inappropriate for the description of the dynamically important large scales. Various other remarks are made relating to the analytic treatment of strong drift-wave-like turbulence.
Date: July 1, 1986
Creator: Krommes, John A.
Object Type: Report
System: The UNT Digital Library
Power transport to the PDX scoop limiter (open access)

Power transport to the PDX scoop limiter

Power transport to the PDX graphite scoop limiter was measured during both ohmic- and neutral-beam-heated discharges by observing its front face temperatures using an infrared camera. Measurements were made as a function of plasma density, current, position, fueling mode, and heating power for both co- and counter-neutral beam injection. The measured thermal load on the scoop limiter was 25 to 50% of the total plasma heating power. The measured peak front face midplane temperature was 1500/sup 0/C corresponding to a peak surface power density of 3 kW/cm/sup 2/. This power density implies an effective parallel power flow of 54 kW/cm/sup 2/ in agreement with the radial power distribution extrapolated from TVTS and calorimetry measurements. Symmetric and asymmetric thermal loads were observed. The asymmetric heat loads were predominantly skewed toward the respective ion drift directions for both co- and counter-injected beams. The results of transport calculations are consistent with the direction and magnitude of the observed asymmetries.
Date: July 1, 1986
Creator: Kugel, H.W.; Bol, K.; Budny, R.; Fonck, R.; Goldston, R.; Grek, B. et al.
Object Type: Report
System: The UNT Digital Library
Accelerator and final focus model for an induction Linac based HIF system study (open access)

Accelerator and final focus model for an induction Linac based HIF system study

An overview of the assumptions and models incorporated in the ongoing Induction-Linac-based, HIF System Assessment is presented. Final transport, compression and final focus pose constraints which form a critical link between the accelerator and target requirements. A recent analysis has shown that system costs may be considerably reduced by the use of multiply charges ions. The assumptions underlying this direction are described.
Date: July 1, 1986
Creator: Lee, Edward P.
Object Type: Article
System: The UNT Digital Library
Gyrokinetic particle simulation model (open access)

Gyrokinetic particle simulation model

A new type of particle simulation model based on the gyrophase-averaged Vlasov and Poisson equations is presented. The reduced system, in which particle gyrations are removed from the equations of motion while the finite Larmor radius effects are still preserved, is most suitable for studying low frequency microinstabilities in magnetized plasmas. It is feasible to simulate an elongated system (L/sub parallel/ >> L/sub perpendicular/) with a three-dimensional grid using the present model without resorting to the usual mode expansion technique, since there is essentially no restriction on the size of ..delta..x/sub parallel/ in a gyrokinetic plasma. The new approach also enables us to further separate the time and spatial scales of the simulation from those associated with global transport through the use of multiple spatial scale expansion. Thus, the model can be a very efficient tool for studying anomalous transport problems related to steady-state drift-wave turbulence in magnetic confinement devices. It can also be applied to other areas of plasma physics.
Date: July 1, 1986
Creator: Lee, W. W.
Object Type: Report
System: The UNT Digital Library
Cumulative releases of radionuclides from uncontained waste packages (open access)

Cumulative releases of radionuclides from uncontained waste packages

This report describes mathematical predictions for the migration of radionuclides from an emplaced radioactive waste container. The model assumes a spherical-equivalent waste solid surrounded by backfill but neglects the effect of decay heat. 7 refs., 2 tabs. (TEM)
Date: July 1, 1986
Creator: Lee, W. W. L.; Kim, C. L.; Chambre, P. L. & Pigford, T. H.
Object Type: Article
System: The UNT Digital Library
Diffusion quantum Monte Carlo for molecules (open access)

Diffusion quantum Monte Carlo for molecules

A quantum mechanical Monte Carlo method has been used for the treatment of molecular problems. The imaginary-time Schroedinger equation written with a shift in zero energy (E/sub T/ - V(R)) can be interpreted as a generalized diffusion equation with a position-dependent rate or branching term. Since diffusion is the continuum limit of a random walk, one may simulate the Schroedinger equation with a function psi (note, not psi/sup 2/) as a density of ''walks.'' The walks undergo an exponential birth and death as given by the rate term. 16 refs., 2 tabs.
Date: July 1, 1986
Creator: Lester, W. A. Jr.
Object Type: Article
System: The UNT Digital Library
Performance evaluation of the HEP, ELXSI and CRAY X-MP parallel processors on hydrocode test problems (open access)

Performance evaluation of the HEP, ELXSI and CRAY X-MP parallel processors on hydrocode test problems

Parallel programming promises improved processing speeds for hydrocodes, magnetohydrocodes, multiphase flow codes, thermal-hydraulics codes, wavecodes and other continuum dynamics codes. This paper presents the results of some investigations of parallel algorithms on three parallel processors: the CRAY X-MP, ELXSI and the HEP computers. Introduction and Background: We report the results of investigations of parallel algorithms for computational continuum dynamics. These programs (hydrocodes, wavecodes, etc.) produce simulations of the solutions to problems arising in the motion of continua: solid dynamics, liquid dynamics, gas dynamics, plasma dynamics, multiphase flow dynamics, thermal-hydraulic dynamics and multimaterial flow dynamics. This report restricts its scope to one-dimensional algorithms such as the von Neumann-Richtmyer (1950) scheme.
Date: July 7, 1986
Creator: Liebrock, L. M.; McGrath, J. F. & Hicks, D. L.
Object Type: Article
System: The UNT Digital Library
TRAC-PF1/MOD1: an advanced best-estimate computer program for pressurized water reactor thermal-hydraulic analysis (open access)

TRAC-PF1/MOD1: an advanced best-estimate computer program for pressurized water reactor thermal-hydraulic analysis

The Los Alamos National Laboratory is developing the Transient Reactor Analysis Code (TRAC) to provide advanced best-estimate predictions of postulated accidents in light-water reactors. The TRAC-PF1/MOD1 program provides this capability for pressurized water reactors and for many thermal-hydraulic test facilities. The code features either a one- or a three-dimensional treatment of the pressure vessel and its associated internals, a two-fluid nonequilibrium hydrodynamics model with a noncondensable gas field and solute tracking, flow-regime-dependent constitutive equation treatment, optional reflood tracking capability for bottom-flood and falling-film quench fronts, and consistent treatment of entire accident sequences including the generation of consistent initial conditions. The stability-enhancing two-step (SETS) numerical algorithm is used in the one-dimensional hydrodynamics and permits this portion of the fluid dynamics to violate the material Courant condition. This technique permits large time steps and, hence, reduced running time for slow transients.
Date: July 1, 1986
Creator: Liles, D.R. & Mahaffy, J.H.
Object Type: Report
System: The UNT Digital Library
Analysis of data bases for health services research on dementia (open access)

Analysis of data bases for health services research on dementia

This report offers different sources of data regarding different forms of dementia, as well as illustrations and applications in a different settings.
Date: July 1986
Creator: Liu, Korbin
Object Type: Report
System: The UNT Digital Library
Linear accelerators of the future (open access)

Linear accelerators of the future

Some of the requirements imposed on future linear accelerators to be used in electron-positron colliders are reviewed, as well as some approaches presently being examined for meeting those requirements. RF sources for use in these linacs are described, as well as wakefields, single bunches, and multiple-bunch trains. (LEW)
Date: July 1, 1986
Creator: Loew, G.A.
Object Type: Article
System: The UNT Digital Library
Fixed point structure of quenched, planar quantum electrodynamics (open access)

Fixed point structure of quenched, planar quantum electrodynamics

Gauge theories exhibiting a hierarchy of fermion mass scales may contain a pseudo-Nambu-Boldstone boson of spontaneously broken scale invariance. The relation between scale and chiral symmetry breaking is studied analytically in quenched, planar quantum electrodynamics in four dimensions. The model possesses a novel nonperturbative ultraviolet fixed point governing its strong coupling phase which requires the mixing of four fermion operators. 12 refs.
Date: July 1, 1986
Creator: Love, S.T.
Object Type: Article
System: The UNT Digital Library
OncoLog, Volume 31, Number 3, July-September 1986 (open access)

OncoLog, Volume 31, Number 3, July-September 1986

Quarterly newsletter from the University of Texas System Cancer Center, M.D. Anderson Hospital and Tumor Institute discussing cancer care and research to inform physicians.
Date: July 1986
Creator: M.D. Anderson Hospital and Tumor Institute
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Electromagnetic Compatibility and Interference Metrology (open access)

Electromagnetic Compatibility and Interference Metrology

From abstract: The material included in this report is intended for a short course on electromagnetic compatibility/interference (EMC/EMI) metrology to be offered jointly by the staff of the Fields Characterization Group (723.03) and the Interference Characterization Group (723.04) of the Electromagnetic Fields Division (723). The purpose of this short course is to present a review of some of the radiated EMC/EMI measurement methods, to which the National Bureau of Standards (NBS) at Boulder, Colorado, has made significant contributions during the past two decades.
Date: July 1986
Creator: Ma, Mark T. & Kanda, M.
Object Type: Report
System: The UNT Digital Library
Foams in porous media (open access)

Foams in porous media

In 1978 a literature search on selective blocking of fluid flow in porous media was done by Professor S.S. Marsden and two of his graduate students, Tom Elson and Kern Huppy. This was presented as SUPRI Report No. TR-3 entitled ''Literature Preview of the Selected Blockage of Fluids in Thermal Recovery Projects.'' Since then a lot of research on foam in porous media has been done on the SUPRI project and a great deal of new information has appeared in the literature. Therefore we believed that a new, up-to-date search should be done on foam alone, one which would be helpful to our students and perhaps of interest to others. This is a chronological survey showing the development of foam flow, blockage and use in porous media, starting with laboratory studies and eventually getting into field tests and demonstrations. It is arbitrarily divided into five-year time periods. 81 refs.
Date: July 1, 1986
Creator: Marsden, S.S.
Object Type: Report
System: The UNT Digital Library
Searches for monopoles and quarks (open access)

Searches for monopoles and quarks

Within the last year, several sensitive searches for monopoles and quarks have been done. Recent experiments at the Tevatron and at the CERN p anti p collider have detected no evidence for free fractional charge. An experiment in a iron refinery, which searched for GUT monopoles trapped in iron ore with two SQUID detectors, found no monopole candidate. However, an experiment looking for monopoles in cosmic rays has measured an interesting event which could be interpreted as a monopole. Several detectors are being built to achieve significant improvements in sensitivity for detection of quarks and monopoles. 21 refs.
Date: July 1, 1986
Creator: Matis, H.S.
Object Type: Article
System: The UNT Digital Library
Measuring and modeling solar irradiance on vertical surfaces (open access)

Measuring and modeling solar irradiance on vertical surfaces

This report presents the first evaluations of 5 algorithms for converting global horizontal and direct normal solar irradiance components to global irradiance on tilted surfaces using measurements from the Solar Radiation Research Laboratory (SRRL) at SERI. High resolution (15-min) measurements from 8 thermopile radiometers oriented vertically in the 4 cardinal directions were available for a 169-day period ending 31 December 1984. Concurrent measurements of global horizontal and direct normal solar irradiance components were also used. The pyranometers used were intercompared on horizontal, north-facing, and south-facing vertical orientations. The conversion algorithms each attempt to account for the very complex atmospheric interactions with incoming solar radiation. The sky and ground radiance contributions to tilted surface are assumed to be isotropic, anisotropic, or a combination of the two depending on the algorithm. Results from the analysis of measurements on vertical surfaces for 22 July through 4 September indicate a general overestimate (18% to 46.5%) of solar irradiance on north-facing surfaces by all 5 of the algorithms. The best agreement with measured data was demonstrated for south-facing surfaces where all but one algorithm were within the present measurement by as much as 23% of the observed 15-min data.
Date: July 1, 1986
Creator: Maxwell, Eugene L.; Stoffel, T. L. & Bird, R. E.
Object Type: Report
System: The UNT Digital Library
Long-term projections of national, regional, and state population (open access)

Long-term projections of national, regional, and state population

The projections prepared by the US Bureau of the Census are the best available projections of total US population. The DRI projections of population at the regional and state level to the year 2008 are the best available and are consistent with the US Bureau of the Census projections of total US population. The DRI regional and state projections can be extended from 2008 to 2030 with a simple model based on economic opportunity, although an even simpler model - constant shares - is used for the 1985 test runs. The US Bureau of the Census prepares the best available projections of the US age-sex distribution.
Date: July 1, 1986
Creator: McDonald, J. F. & South, D. W.
Object Type: Report
System: The UNT Digital Library
Satellite telecommunications technology transfer to China: case study (open access)

Satellite telecommunications technology transfer to China: case study

This report discusses the Chinese satellites and launch capabilities, China's international satellite connection, and the present status and future goals to China's space communications.
Date: July 1986
Creator: McLucas, John & Getsinger, Norman
Object Type: Report
System: The UNT Digital Library
Weldon Spring historical dose estimate (open access)

Weldon Spring historical dose estimate

This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.
Date: July 1, 1986
Creator: Meshkov, N.; Benioff, P.; Wang, J. & Yuan, Y.
Object Type: Report
System: The UNT Digital Library
High field superconducting magnets (12 T and greater) for fusion applications (open access)

High field superconducting magnets (12 T and greater) for fusion applications

The technology for producing high fields in large superconducting magnets has increased greatly in recent years, but must increase still more in the future. In this paper, we examine the present state of the art vis-a-vis the needs of a next-generation fusion machine and outline a program to provide for those needs. We also highlight recent developments that suggest the program goals are within reach.
Date: July 9, 1986
Creator: Miller, J. R.; Summers, L. T. & Kerns, J. A.
Object Type: Article
System: The UNT Digital Library
Infrared thermographic study of laser ignition (open access)

Infrared thermographic study of laser ignition

Pyrotechnic ignition has been studied in the past by making a limited number of discrete temperature-time observations during ignition. Present-day infrared scanning techniques make it possible to record thermal profiles, during ignition, with high spacial and temporal resolution. Data thus obtained can be used with existing theory to characterize pyrotechnic materials and to develop more precise kinetic models of the ignition process. Ignition has been studied theoretically and experimentally using various thermal methods. It has been shown that the whole process can, ideally, be divided into two stages. In the first stage, the sample pellet behaves like an inert body heated by an external heat source. The second stage is governed by the chemical reaction in the heated volume produced during the first stage. High speed thermographic recording of the temperature distribution in the test sample during laser ignition makes it possible to calculate the heat content at any instant. Thus, one can actually observe laser heating and the onset of self-sustained combustion in the pellet.
Date: July 21, 1986
Creator: Mohler, J.H. & Chow, C.T.S.
Object Type: Article
System: The UNT Digital Library
Infrared Thermographic Study of Laser Ignition (open access)

Infrared Thermographic Study of Laser Ignition

Pyrotechnic ignition has been studied in the past by making a limited number of discrete temperature-time observations during ignition. Present-day infrared scanning techniques make it possible to record thermal profiles, during ignition, with high spacial and temporal resolution. Data thus obtained can be used with existing theory to characterize pyrotechnic materials and to develop more precise kinetic models of the ignition process. Ignition has been studied theoretically and experimentally using various thermal methods. It has been shown that the whole process can, ideally, be divided into two stages. In the first stage, the sample pellet behaves like an inert body heated by an external heat source. The second stage is governed by the chemical reaction in the heated volume produced during the first stage. High speed thermographic recording of the temperature distribution in the test sample during laser ignition makes it possible to calculate the heat content at any instant. Thus, one can actually observe laser heating and the onset of self-sustained combustion in the pellet. The experimental apparatus used to make these observations is described. The temperature distributions recorded are shown to be in good agreement with those predicted by heat transfer theory. Heat content values calculated from the …
Date: July 1, 1986
Creator: Mohler, Jonathan H. & Chow, Charles T. S.
Object Type: Article
System: The UNT Digital Library
Production of muons for fusion catalysis in a magnetic mirror configuration. Revision 1 (open access)

Production of muons for fusion catalysis in a magnetic mirror configuration. Revision 1

For muon-catalyzed fusion to be of practical interest, a very efficient means of producing muons must be found. We describe a scheme for producing muons that may be more energy efficient than any heretofore proposed. There are, in particular, some potential advantages of creating muons from collisions of high energy tritons confined in a magnetic mirror configuration. If one could catalyze 200 fusions per muon and employ a uranium blanket that would multiply the neutron energy by a factor of 10, one might produce electricity with an overall plant efficiency (ratio of electric energy produced to nuclear energy released) approaching 30%. One possible near term application of a muon-producing magnetic-mirror scheme would be to build a high-flux neutron source for radiation damage studies. The careful arrangement of triton orbits will result in many of the ..pi../sup -/'s being produced near the axis of the magnetic mirror. The pions quickly decay into muons, which are transported into a small (few-cm-diameter) reactor chamber producing approximately 1-MW/m/sup 2/ neutron flux on the chamber walls, using a laboratory accelerator and magnetic mirror. The costs of construction and operation of the triton injection accelerator probably introduces most of the uncertainty in the viability of this …
Date: July 25, 1986
Creator: Moir, R.W. & Chapline, G.F. Jr.
Object Type: Article
System: The UNT Digital Library
Fusion Energy Division annual progress report, period ending December 31, 1985 (open access)

Fusion Energy Division annual progress report, period ending December 31, 1985

Separate abstracts were prepared for nine of the included sections. (MOW)
Date: July 1, 1986
Creator: Morgan, O. B., Jr.; Berry, L. A. & Sheffield, J.
Object Type: Report
System: The UNT Digital Library