Electromagnetic PIC codes on unstructured grids (open access)

Electromagnetic PIC codes on unstructured grids

This report discusses the following topics in relationships to plasma simulation: unstructed grids; particle tracking; and field propagation. (LSP)
Date: October 12, 1990
Creator: Ambrosiano, J.J.; Brandon, S.T. (Lawrence Livermore National Lab., CA (USA)) & Loehner, R. (George Washington Univ., Washington, DC (USA). School of Engineering and Applied Science)
Object Type: Article
System: The UNT Digital Library
Wideband beam patterns from sparse arrays (open access)

Wideband beam patterns from sparse arrays

Transient radiated fields due to impulsively excited apertures and aperture response due to incident impulsive waves has been the subject of considerable research in acoustics over the last decade. This research is also of importance to wideband radar. Medical ultrasound steered phased arrays use transmitted pulses consisting of from 1 to 3 cycles of a damped sinusoid, which is similar to certain radar systems. As will be shown, planar arrays using ultra-wide band pulses may be formed with very sparsely spaced elements. This makes feasible very high resolution, economical, and relatively simple, steered beam phased arrays. The resolution may be increased simply by moving the array elements further apart. Grating lobes due to aliasing are not formed when the elements are sparsely spaced. In a very sparse wide band array, element spacing effects the form, or signal shape in time, rather than the peak amplitude of the sidelobe structure. The number of elements in the aperture determines the peak sidelobe level which, in theory, may be decreased without limit. 13 refs., 7 figs.
Date: January 12, 1990
Creator: Anderson, F. (Anderson (Forrest), Bernalillo, NM (USA)); Fullerton, L. (Time Domain Systems, Huntsville, AL (USA)); Christensen, W. & Kortegaard, B. (Los Alamos National Lab., NM (USA))
Object Type: Article
System: The UNT Digital Library
Future microprocessor farms: Offline and online (open access)

Future microprocessor farms: Offline and online

Microprocessor farms have been successfully employed in high energy physics for both offline analysis and online triggers. As the experiments continue to grow in size, so do the demands for processing power. The preliminary indications are that the large collider experiments will require at least a million VAX-11/780 equivalents of processing power for online trigger decisions and offline event reconstruction. This paper examines the current technology trends and projects the processing power that may be expected with the current farm architectures. 3 refs., 6 figs.
Date: January 12, 1990
Creator: Areti, H.
Object Type: Report
System: The UNT Digital Library
Mass storage for microprocessor farms (open access)

Mass storage for microprocessor farms

Experiments in high energy physics require high density and high speed mass storage. Mass storage is needed for data logging during the online data acquisition, data retrieval and storage during the event reconstruction and data manipulation during the physics analysis. This paper examines the storage and speed requirements at the first two stages of the experiments and suggests a possible starting point to deal with the problem. 3 refs., 3 figs.
Date: January 12, 1990
Creator: Areti, H.
Object Type: Report
System: The UNT Digital Library
Initial data from the Soudan 2 experiment (open access)

Initial data from the Soudan 2 experiment

Soudan 2 is an 1100-ton tracking calorimeter which is being built 713 m underground to search for nucleon decay and to study neutrino and cosmic-ray physics. The detector is assembled from 256 identical 4.3-ton calorimeter modules. Each module consists of finely segmented iron and drift tubes, and records three space coordinates and dE/dx for every tube crossing. It is surrounded on all sides by a 1700 m{sup 2} active shield of proportional tubes. The first atmospheric neutrino interactions and a magnetic monopole search are described. Prospects for cosmic ray studies are summarized.
Date: October 12, 1990
Creator: Ayres, D.S.
Object Type: Article
System: The UNT Digital Library
Simulation of top quark production at D0 (open access)

Simulation of top quark production at D0

The production of top at the Fermilab Tevatron D0 detector was investigated using full Monte Carlo and event reconstruction packages. In total, 480 events were generated for m{sub T} = 150 GeV/c{sup 2} in the specific t({bar t}) {yields} b({bar b}) + W{sup {plus minus}}, with at least one W decaying to leptons. These events were then analyzed in an attempt to find characteristic signals for top production at D0. 21 figs.
Date: May 12, 1990
Creator: Barter, C.M.
Object Type: Report
System: The UNT Digital Library
Assuring both quality and creativity in basic research (open access)

Assuring both quality and creativity in basic research

How does one assure that both quality and creativity are obtained in basic research environments QA theoreticians have attempted to develop workable definitions of quality, but in more reflective moments, these definitions often fail to capture the deeper essence of the idea of quality.'' This paper asserts that creativity (as a product of the human mind) is a concrete interface between perfunctory definitions of quality (conformance to specifications) and more philosophical speculations about the nature of quality- related ultimates'' like elegance or beauty. In addition, we describe the distinction between creative ideas and creative acts and highlight one of the major inhibitors of creativity, fear. Finally we show that highly creative people often have an irreverent attitude toward boundaries and established authority, and discuss how one can allow for this when designing a QA program in a basic research environment.
Date: April 12, 1990
Creator: Bodnarczuk, Mark
Object Type: Article
System: The UNT Digital Library
The Social Structure of Experimental'' Strings at Fermilab; A Physics and Detector Driven Model (open access)

The Social Structure of Experimental'' Strings at Fermilab; A Physics and Detector Driven Model

Physicists in HEP have been forced to organize large scientific projects without a well defined organizational or sociological model to guide them. In the absence of such models, what structures do experimentalists use to develop social structures in HEP In this paper, I claim that physicists organize around what they know best, the physics problems they study and the detectors and devices they study them with. After describing the advent of management'' in HEP, I use a case study of 4 Fermilab experiments as the base upon which to propose a physics and detector driven model of social structure for experiments. In addition, I show how this model can be extended to describe strings'' of experiments, where continuities of physics interests, spectrometer design, and a core group of physicists become a definable sociological unit that can exist for over 15 years. A dominate theme that emerges from my analysis is the conscious attempt on the part of experimenters to remove the uncertainties that are part of the practice of HEP.
Date: December 12, 1990
Creator: Bodnarczuk, Mark
Object Type: Report
System: The UNT Digital Library
(Environmental technology) (open access)

(Environmental technology)

The traveler participated in a conference on environmental technology in Paris, sponsored by the US Embassy-Paris, US Environmental Protection Agency (EPA), the French Environmental Ministry, and others. The traveler sat on a panel for environmental aspects of energy technology and made a presentation on the potential contributions of Oak Ridge National Laboratory (ORNL) to a planned French-American Environmental Technologies Institute in Chattanooga, Tennessee, and Evry, France. This institute would provide opportunities for international cooperation on environmental issues and technology transfer related to environmental protection, monitoring, and restoration at US Department of Energy (DOE) facilities. The traveler also attended the Fourth International Conference on Environmental Contamination in Barcelona. Conference topics included environmental chemistry, land disposal of wastes, treatment of toxic wastes, micropollutants, trace organics, artificial radionuclides in the environment, and the use biomonitoring and biosystems for environmental assessment. The traveler presented a paper on The Fate of Radionuclides in Sewage Sludge Applied to Land.'' Those findings corresponded well with results from studies addressing the fate of fallout radionuclides from the Chernobyl nuclear accident. There was an exchange of new information on a number of topics of interest to DOE waste management and environmental restoration needs.
Date: October 12, 1990
Creator: Boston, H.L.
Object Type: Report
System: The UNT Digital Library
Physics data base for the beam plasma neutron source (BPNS) (open access)

Physics data base for the beam plasma neutron source (BPNS)

A 14-MeV deuterium-tritium (D-T) neutron source for accelerated end-of-life testing of fusion reactor materials has been designed on the basis of a linear two-component collisional plasma system. An intense flux (up to 5 {times} 10{sup 18}/m{sup 2}{center dot}s) of 14-MeV neutrons is produced in a fully ionized high-density (n{sub e} {approx equal} 3 {times} 10{sup 21} m{sup {minus}3}) tritium target by transverse injection of 60 MW of neutral beam power. Power deposited in the target is removed by thermal electron conduction to large end chambers, where it is deposited in gaseous plasma collectors. We show in this paper that the major physics issues have now been experimentally demonstrated. These include magnetohydrodynamic (MHD) equilibrium and stability, microstability, startup, fueling, Spitzer electron thermal conductivity, and power deposition in a gaseous plasma collector. However, an integrated system has not been demonstrated. 28 refs., 8 figs., 2 tabs.
Date: October 12, 1990
Creator: Coensgen, F. H.; Casper, T. A.; Correll, D. L.; Damm, C. C.; Futch, A. H. & Molvik, A. W.
Object Type: Article
System: The UNT Digital Library
Evaluation of Y-12 landfill (open access)

Evaluation of Y-12 landfill

The purpose of this project was to provide team members with practical experience in application of Civil Engineering 555, Solid Waste Management principles. Team members chose to evaluate the functional elements of the Oak Ridge Y-12 Plant's (Y-12's) solid waste management system. The following factors contributed to selection of Y-12'system for evaluation: team members' familiarity with the Y-12 system; knowledge that the Y-12 Centralized Sanitary Landfill II was nearing capacity; and presence of the unique issues posed by special national security and potential radioactive contamination considerations. This report was limited to evaluation of the solid waste management system for conventional solid waste; hazardous radioactive, and radioactive mixed waste were not addressed. The report: (1) describes each functional element including waste generation, storage, collection, transport, processing, recovery, and disposal; (2) identifies and evaluates alternatives for each element and (3) identifies system strengths and recommends opportunities for improvement. 34 figs.
Date: December 12, 1990
Creator: Crawford, G.A. (Bechtel National, Inc., San Francisco, CA (USA)); Daugherty, D.L. (Oak Ridge National Lab., TN (USA)); Hutzler, C.W.; Smith, C.M. (Oak Ridge Y-12 Plant, TN (USA)) & Wylie, A.N. (Adams, Craft, Herz, Walker, Inc., Oak Ridge, TN (USA))
Object Type: Report
System: The UNT Digital Library
Nonlinear optics with focused x-ray lasers (open access)

Nonlinear optics with focused x-ray lasers

We have investigated the possibility of focusing x-ray lasers with the use of multilayered mirrors or zone plates. The results indicate that x-ray intensities as high as 10{sup 14} W/cm{sup 2} can be achieved by focusing saturated Ne-like x-ray lasers. These intensities should be adequate for studying nonlinear optical phenomena. 9 refs., 2 figs.
Date: December 12, 1990
Creator: DaSilva, L. B.; Muendel, M. H.; Falcone, R. W.; Fields, D. J.; Kortright, J. B.; MacGowan, B. J. et al.
Object Type: Article
System: The UNT Digital Library
CC Pressure Test (open access)

CC Pressure Test

The inner vessel heads including bypass and beam tubes had just been welded into place and dye penetrant checked. The vacuum heads were not on at this time but the vacuum shell was on covering the piping penetrating into the inner vessel. Signal boxes with all feed through boards, the instrumentation box, and high voltage boxes were all installed with their pump outs capped. All 1/4-inch instrumentation lines were terminated at their respective shutoff valves. All vacuum piping used for pumping down the inner vessel was isolated using o-ring sealed blind flanges. PV215A (VAT Series 12), the 4-inch VRC gate valve isolating the cyropump, and the rupture disk had to be removed and replaced with blind flanges before pressurizing due to their pressure limitations. Stresses in plates used as blind flanges were checked using Code calcualtions. Before the CC test, vacuum style blanks and clamps were hydrostatically pressure tested to 150% of the maximum test pressure, 60 psig. The Code inspector and Research Division Safety had all given their approval to the test pressure and procedure prior to filling the vessel with argon. The test was a major success. Based on the lack of any distinguishable pressure drop indicated on …
Date: July 12, 1990
Creator: Dixon, K.
Object Type: Report
System: The UNT Digital Library
Fusion reactor design studies. [ARIES Tokamak] (open access)

Fusion reactor design studies. [ARIES Tokamak]

This report discusses the following topics on the ARIES tokamak: systems; plasma power balance; impurity control and fusion ash removal; fusion product ripple loss; energy conversion; reactor fueling; first wall design; shield design; reactor safety; and fuel cost and resources. (LSP)
Date: October 12, 1990
Creator: Emmert, G.A.; Kulcinski, G.L. & Santarius, J.F.
Object Type: Report
System: The UNT Digital Library
Is There Hope for Fusion (open access)

Is There Hope for Fusion

From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025--2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 4 figs., 3 tabs.
Date: April 12, 1990
Creator: Fowler, T. K.
Object Type: Article
System: The UNT Digital Library
Damped time advance methods for particles and EM fields (open access)

Damped time advance methods for particles and EM fields

Recent developments in the application of damped time advance methods to plasma simulations include the synthesis of implicit and explicit adjustably damped'' second order accurate methods for particle motion and electromagnetic field propagation. This paper discusses this method.
Date: October 12, 1990
Creator: Friedman, A.; Ambrosiano, J.J.; Boyd, J.K.; Brandon, S.T.; Nielsen, D.E. Jr. & Rambo, P.W.
Object Type: Article
System: The UNT Digital Library
Mechanistic studies of carbon monoxide reduction (open access)

Mechanistic studies of carbon monoxide reduction

The progress made during the current grant period (1 January 1988--1 April 1990) in three different areas of research is summarized. The research areas are: (1) oxidatively-induced double carbonylation reactions to form {alpha}-ketoacyl complexes and studies of the reactivity of the resulting compounds, (2) mechanistic studies of the carbonylation of nitroaromatics to form isocyanates, carbamates, and ureas, and (3) studies of the formation and reactivity of unusual metallacycles and alkylidene ligands supported on binuclear iron carbonyl fragments. 18 refs., 5 figs., 1 tab.
Date: June 12, 1990
Creator: Geoffroy, G.L.
Object Type: Report
System: The UNT Digital Library
Development and application of photosensitive device systems to studies of biological and organic materials (open access)

Development and application of photosensitive device systems to studies of biological and organic materials

This report discusses the following basic research accomplishments: new x-ray structure determination methods were developed and applied to biomembrane lipid phases; a novel mechanism for general anesthesia was proposed; the elastic properties of membranes were investigated, both theoretically and experimentally; the effects of high pressures on membranes were studied; neutron diffraction was used to probe mesophase structure; and novel lipid and surfactant systems are characterized. Also discussed are instrumentation accomplishments.
Date: July 12, 1990
Creator: Gruner, S. M. & Reynolds, G. T.
Object Type: Report
System: The UNT Digital Library
(Structural investigation of curium bismuthide) (open access)

(Structural investigation of curium bismuthide)

The primary objective of the collaborative studies with EITU was to study curium bismuthide using energy dispersive X-ray diffraction to monitor its structure as a function of pressure. This objective was accomplished and the material was investigated up to 0.48 megabars of pressure. These studies were a continuation of established and productive collaborations between ORNL and EITU. The study of this curium compound is significant in that it is the first 5f-element bismuthide to be studied under pressure. Bismuth has the highest Z and the largest radius of the pnictogen group of elements (important for Hill Plot assessments) and has the greatest potential to form f-p type bonding with actinides under pressure. From a preliminary assessment of our experimental data it has been determined that two structural transitions occurred in the curium bismuthide sample as a result of the applied pressure.
Date: October 12, 1990
Creator: Haire, R.G.
Object Type: Report
System: The UNT Digital Library
Weak scale supersymmetry (open access)

Weak scale supersymmetry

An introduction to the ideas and current state of weak scale supersymmetry is given. It is shown that LEP data on Z decays has already excluded two of the most elegant models of weak scale supersymmetry. 14 refs.
Date: November 12, 1990
Creator: Hall, L. J.
Object Type: Article
System: The UNT Digital Library
Stratospheric ozone conservation by electron attachment to chlorine atoms: The negative-ion chemistry (open access)

Stratospheric ozone conservation by electron attachment to chlorine atoms: The negative-ion chemistry

Creating low-energy electrons in the stratosphere by photoelectric emission has the beneficial effect of suppressing ozone destruction by Cl. This is because Cl is converted to Cl{sup {minus}}, which is less reactive. Critical to the success of this scheme is the ability to attach most of the electrons to Cl{sup {minus}} and its hydrates Cl{sup {minus}} (H{sub 2}O). We found that this attachment efficiency is rather high. This is remarkable given the fact that the electron affinity of Cl{sup {minus}} is less than that of NO{sub 3}{minus}. Photoddetachment of NO{sub 3}{minus} is the key factor that leads to this high efficiency. Computer calculations show that ozone increases with electron injection, and most of the electrons end up attaching to Cl{sup {minus}}(H{sub 2}O). We also point out that 40 km, the altitude at which most of the ozone destruction occurs, is also the optimum altitude for injecting photoelectric electrons. 12 refs., 6 figs.
Date: October 12, 1990
Creator: Ho, D.D.M. (Lawrence Livermore National Lab., CA (USA)); Tsang, K.T. (Science Applications International Corp., McLean, VA (USA)); Wong, A.Y. & Siverson, R.J. (California Univ., Los Angeles, CA (USA). Dept. of Physics)
Object Type: Article
System: The UNT Digital Library
Preparation of Biliquid Foam Compositions (open access)

Preparation of Biliquid Foam Compositions

Technology developed by the late Dr. Felix Sebba of the VPI Chemical Engineering Department by which an oil phase can be broken up into small droplets and encapsulated in a continuous water phase led to research on the possible merits of a fuel prepared by this procedure. The resulting mixture is called a polyaphron. Part 1 of this report describes the testing of polyaphronated gasoline in an automobile engine. Nitrogen oxides (NO{sub x}) emissions, total hydrocarbon (HC) emissions, and exhaust temperature were determined for various load and RPM combinations. Difficulties with viscosity and separation of the water phase have prevented complete testing at road load conditions. Rather than continue with engine testing, some bench tests of polyaphrons were performed to see the effect of various filtering processes on fuel stability as well as measuring viscosity and density. These results are reported in Part 2 of this paper. 6 figs., 4 tabs.
Date: December 12, 1990
Creator: Jaasma, D. R.; Osucha, D. C. & Scheuren, J.
Object Type: Report
System: The UNT Digital Library
Laser-based flow cytometric analysis of genotoxicity of humans exposed to ionizing radiation during the Chernobyl accident (open access)

Laser-based flow cytometric analysis of genotoxicity of humans exposed to ionizing radiation during the Chernobyl accident

An analytical technique has been developed that allows laser-based flow cytometric measurement of the frequency of red blood cells that have lost allele-specific expression of a cell surface antigen due to genetic toxicity in bone marrow precursor cells. Previous studies demonstrated a correlation of such effects with the exposure of each individual to mutagenic phenomena, such as ionizing radiation, and the effects can persist for the lifetime of each individual. During the emergency response to the nuclear power plant accident at Chernobyl, Ukraine, USSR, a number of people were exposed to whole body doses of ionizing radiation. Some of these individuals were tested with this laser-based assay and found to express a dose-dependent increase in the frequency of variant red blood cells that appears to be a persistent biological effect. All data indicate that this assay might well be used as a biodosimeter to estimate radiation dose and also as an element to be used for estimating the risk of each individual to develop cancer due to radiation exposure. 17 refs., 5 figs.
Date: September 12, 1990
Creator: Jensen, R.H.; Bigbee, W.L.; Langlois, R.G.; Grant, S.G. (Lawrence Livermore National Lab., CA (USA)); Pleshanov, P.G. (Ministerstvo Zdravookhraneniya SSSR, Moscow (USSR)); Chirkov, A.A. (Institut Biofiziki, Moscow (USSR)) et al.
Object Type: Article
System: The UNT Digital Library
Liquid Argon Maximm Convective Heat Flux vs. Liquid Depth (open access)

Liquid Argon Maximm Convective Heat Flux vs. Liquid Depth

In order to help answer questions about the magnitude of heat flux to the liquid argon in a liquid argon calorimeter which could cause boiling (bubbles), calculations estimating the heat flux which can be removed by free convection were made in February, 1988. These calculations are intended to be an estimate of the heat flux above which boiling would occur. No formal writeup was made of these calculations, although the graph dated 3 Feb 88 and revised (adding low-velocity forced convection lines) 19 Feb 88 was presented in several meetings and widely distributed. With this description of the calculations, copies of the original graph and calculations are being added to the D0 Engineering Note files. The liquid argon surface is in equilibrium with argon vapor at a pressure of 1.3 bar, so the surface is at 89.70 K. The liquid is entirely at this surface temperature throughout the bulk of the volume, except locally where it is warmed by a solid surface at a higher temperature than the bulk liquid. This surface temperature is taken to be the boiling temperature of argon at the pressure corresponding to 1.3 bar plus the liquid head; hence it is a function of depth …
Date: January 12, 1990
Creator: Peterson, T.
Object Type: Report
System: The UNT Digital Library