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Engineering problems in the development of fusion power reactors (open access)

Engineering problems in the development of fusion power reactors

This paper reviews current progress in the development of fusion power from the engineering point of view and highlights the most outstanding technical issues which must be resolved. (MOW)
Date: November 2, 1976
Creator: Varljen, T. C.
System: The UNT Digital Library
Design issues for a laboratory high gain fusion facility (open access)

Design issues for a laboratory high gain fusion facility

In an inertial fusion laboratory high gain facility, experiments will be carried out with up to 1000 MJ of thermonuclear yield. The experiment area of such a facility will include many systems and structures that will have to operate successfully in the difficult environment created by the sudden large energy release. This paper estimates many of the nuclear effects that will occur, discusses the implied design issues and suggests possible solutions so that a useful experimental facility can be built. 4 figs.
Date: November 2, 1987
Creator: Hogan, W.J.
System: The UNT Digital Library
OCR vision system, an alternative to bar code (open access)

OCR vision system, an alternative to bar code

This report describes optical character reader system advantages and applications. Comparisons are made to bar code readers. (JDH)
Date: November 2, 1987
Creator: Leader, D R
System: The UNT Digital Library
TIBER II/ETR (Engineering Test Reactor) nuclear shielding and optional tritium breeding system: An overview (open access)

TIBER II/ETR (Engineering Test Reactor) nuclear shielding and optional tritium breeding system: An overview

TIBER II, the Tokamak Ignition/Burn Experimental Reactor II, is a design concept developed as the US candidate for an International Engineering Test Reactor (ETR). An important objective of this design is to minimize cost by minimizing major radius while providing a wall loading greater than 1.0 MW/m2 and a total fluence greater than 3.0 MWY/m2 needed for blanket module testing. The shielding required for the superconducting TF coils is an important element in setting TIBER II's 3.0m major radius. 6 refs., 1 fig., 1 tab.
Date: November 2, 1987
Creator: Lee, J. D. & Sawan, M.
System: The UNT Digital Library
Verifying the Cosmological Utility of Type Ia Supernovae:Implications of a Dispersion in the Ultraviolet Spectra (open access)

Verifying the Cosmological Utility of Type Ia Supernovae:Implications of a Dispersion in the Ultraviolet Spectra

We analyze the mean rest-frame ultraviolet (UV) spectrum ofType Ia Supernovae(SNe) and its dispersion using high signal-to-noiseKeck-I/LRIS-B spectroscopyfor a sample of 36 events at intermediateredshift (z=0.5) discoveredby the Canada-France-Hawaii TelescopeSupernova Legacy Survey (SNLS). Weintroduce a new method for removinghost galaxy contamination in our spectra,exploiting the comprehensivephotometric coverage of the SNLS SNe and theirhost galaxies, therebyproviding the first quantitative view of the UV spectralproperties of alarge sample of distant SNe Ia. Although the mean SN Ia spectrumhas notevolved significantly over the past 40 percent of cosmic history,preciseevolutionary constraints are limited by the absence of acomparable sample ofhigh quality local spectra. The mean UV spectrum ofour z 0.5 SNe Ia and itsdispersion is tabulated for use in futureapplications. Within the high-redshiftsample, we discover significant UVspectral variations and exclude dust extinctionas the primary cause byexamining trends with the optical SN color. Although progenitormetallicity may drive some of these trends, the variations we see aremuchlarger than predicted in recent models and do not follow expectedpatterns.An interesting new result is a variation seen in the wavelengthof selected UVfeatures with phase. We also demonstrate systematicdifferences in the SN Iaspectral features with SN lightcurve width inboth the UV and the optical. Weshow that these intrinsic variations couldrepresent …
Date: November 2, 2007
Creator: Ellis, R. S.; Sullivan, M.; Nugent, P. E.; Howell, D. A.; Gal-Yam, A.; Astier, P. et al.
System: The UNT Digital Library
Incorporating anisotropic electronic structure in crystallographic determination of complex metals: iron and plutonium (open access)

Incorporating anisotropic electronic structure in crystallographic determination of complex metals: iron and plutonium

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Date: November 2, 2005
Creator: Moore, K; Laughlin, D; Soderlind, P & Schwartz, A
System: The UNT Digital Library
Transmission Electron Microscopy Characterization of Helium Bubbles in Aged Plutonium (open access)

Transmission Electron Microscopy Characterization of Helium Bubbles in Aged Plutonium

The self-irradiation damage generated by alpha decay of plutonium results in the formation of lattice defects, helium, and uranium atoms. Over time, microstructural evolution resulting from the self-irradiation may influence the physical and mechanical properties of the material. In order to assess microstructural changes, we have developed and applied procedures for the specimen preparation, handling, and transmission electron microscopy characterization of Pu alloys. These transmission electron microscopy investigations of Pu-Ga alloys ranging in age up to 42-years old reveal the presence of nanometer-sized helium bubbles. The number density of bubbles and the average size have been determined for eight different aged materials.
Date: November 2, 2004
Creator: Schwartz, A J; Wall, M A; Zocco, T G & Blobaum, K M
System: The UNT Digital Library
MRF Applications: Measurement of Process-dependent Subsurface Damage in Optical Materials using the MRF Wedge Technique (open access)

MRF Applications: Measurement of Process-dependent Subsurface Damage in Optical Materials using the MRF Wedge Technique

Understanding the behavior of fractures and subsurface damage in the processes used during optic fabrication plays a key role in determining the final quality of the optical surface finish. During the early stages of surface preparation, brittle grinding processes induce fractures at or near an optical surface whose range can extend from depths of a few mm to hundreds of mm depending upon the process and tooling being employed. Controlling the occurrence, structure, and propagation of these sites during subsequent grinding and polishing operations is highly desirable if one wishes to obtain high-quality surfaces that are free of such artifacts. Over the past year, our team has made significant strides in developing a diagnostic technique that combines magnetorheological finishing (MRF) and scanning optical microscopy to measure and characterize subsurface damage in optical materials. The technique takes advantage of the unique nature of MRF to polish a prescribed large-area wedge into the optical surface without propagating existing damage or introducing new damage. The polished wedge is then analyzed to quantify subsurface damage as a function of depth from the original surface. Large-area measurement using scanning optical microscopy provides for improved accuracy and reliability over methods such as the COM ball-dimple technique. …
Date: November 2, 2005
Creator: Menapace, J A; Davis, P J; Steele, W A; Wong, L L; Suratwala, T I & Miller, P E
System: The UNT Digital Library
Diffusion-controlled spherulite growth in obsidian inferred from H2O concentration profiles (open access)

Diffusion-controlled spherulite growth in obsidian inferred from H2O concentration profiles

Spherulites are spherical clusters of radiating crystals that occur naturally in rhyolitic obsidian. The growth of spherulites requires diffusion and uptake of crystal forming components from the host rhyolite melt or glass, and rejection of non-crystal forming components from the crystallizing region. Water concentration profiles measured by synchrotron-source Fourier transform spectroscopy reveal that water is expelled into the surrounding matrix during spherulite growth, and that it diffuses outward ahead of the advancing crystalline front. We compare these profiles to models of water diffusion in rhyolite to estimate timescales for spherulite growth. Using a diffusion-controlled growth law, we find that spherulites can grow on the order of days to months at temperatures above the glass transition. The diffusion-controlled growth law also accounts for spherulite size distribution, spherulite growth below the glass transition, and why spherulitic glasses are not completely devitrified.
Date: November 2, 2007
Creator: Watkins, Jim; Watkins, Jim; Manga, Michael; Huber, Christian & Martin, Michael C.
System: The UNT Digital Library
America's Atomic Army: The Historical Archaeology of Camp Desert Rock (open access)

America's Atomic Army: The Historical Archaeology of Camp Desert Rock

Established in 1951, Camp Desert Rock served as the training ground for America's 'Atomic Army'. For the next six years, U.S. ground troops traveled to the Nevada desert to participate in military maneuvers during atmospheric atomic weapons testing. Nearly 60,000 soldiers received physical and psychological training in atomic warfare. Abandoned when atmospheric testing ended, Camp Desert Rock was dismantled and its buildings moved to other locations. Today, the camp appears as a sterile expanse of desert marked by rock-lined tent platforms, concrete foundations, and trash scatters. Although visually unimposing, the site is rich with the history of America's nuclear testing program.
Date: November 2, 2007
Creator: Edwards, Susan R.
System: The UNT Digital Library
Bower Cabin (open access)

Bower Cabin

The Bower Cabin, located in southern Nevada, was built and occupied by B.M. Bower and her family during the early 1920s. Bower, a prominent writer of western novels, had over 90 novels to her credit. She wrote 11 of the stories while living at the cabin and, at times, incorporated the surrounding landscape features, including the cabin site itself, into them. The site was subsequently used by a gang of rustlers and for a mining base camp. Archaeological research has identified the remnants of the main structures at the site as well as the artifact material and nearby mining activities associated with the Bower and later occupations.
Date: November 2, 2007
Creator: Drollinger, Harold
System: The UNT Digital Library
Phenomenology of the left-right twin Higgs model (open access)

Phenomenology of the left-right twin Higgs model

The twin Higgs mechanism was proposed recently to solve the little hierarchy problem. We study the implementation of the twin Higgs mechanism in left-right models. At the TeV scale, heavy quark and gauge bosonsappear, with rich collider phenomenology. In addition, there are extra Higgs bosons, some of which couple to both the standard model fermion sector and the gauge sector, while others couple to the gauge bosons only. We present the particle spectrum and study the general features of the collider phenomenology of this class of model at the Large Hadron Collider.
Date: November 2, 2006
Creator: Goh, Hock-Seng; Goh, Hock-Seng & Su, Shufang
System: The UNT Digital Library
The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007), (open access)

The IceCube Collaboration:contributions to the 30 th International Cosmic Ray Conference (ICRC 2007),

This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends IceCube's reach to lower energies. Before the deployment of IceTop, cosmic air showers were registered with the 30 station SPASE-2 surface array. IceCube's low noise Digital Optical Modules are very reliable, show a uniform response and record waveforms of arriving photons that are resolvable with nanosecond precision over a large dynamic range. Data acquisition, reconstruction and simulation …
Date: November 2, 2007
Creator: Collaboration, IceCube & Ackermann, M.
System: The UNT Digital Library
On the extragalactic origin of gamma-ray bursts (open access)

On the extragalactic origin of gamma-ray bursts

A theory to explain the origin of extragalactic gamma ray bursts is presented. Collisions of black dwarf and neutron stars with a subsequent fragmentation of the dwarf producing relativistic particle accelerations toward the neutron star and a resulting turbulent flow of material at the neutron star surface is postulated. (DWL)
Date: November 2, 1984
Creator: Johnson, M. & Teller, E.
System: The UNT Digital Library
Potential Health Risks From Postulated Accidents Involving the Pu-238 RTG (Radioisotope Thermoelectric Generator) on the Ulysses Solar Exploration Mission (open access)

Potential Health Risks From Postulated Accidents Involving the Pu-238 RTG (Radioisotope Thermoelectric Generator) on the Ulysses Solar Exploration Mission

Potential radiation impacts from launch of the Ulysses solar exploration experiment were evaluated using eight postulated accident scenarios. Lifetime individual dose estimates rarely exceeded 1 mrem. Most of the potential health effects would come from inhalation exposures immediately after an accident, rather than from ingestion of contaminated food or water, or from inhalation of resuspended plutonium from contaminated ground. For local Florida accidents (that is, during the first minute after launch), an average source term accident was estimated to cause a total added cancer risk of up to 0.2 deaths. For accidents at later times after launch, a worldwide cancer risk of up to three cases was calculated (with a four in a million probability). Upper bound estimates were calculated to be about 10 times higher. 83 refs.
Date: November 2, 1990
Creator: Goldman, M. (California Univ., Davis, CA (USA)); Nelson, R.C. (EG and G Idaho, Inc., Idaho Falls, ID (USA)); Bollinger, L. (Air Force Inspection and Safety Center, Kirtland AFB, NM (USA)); Hoover, M.D. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (USA). Inhalation Toxicology Research Inst.); Templeton, W. (Pacific Northwest Lab., Richland, WA (USA)) & Anspaugh, L. (Lawren
System: The UNT Digital Library
Radiological Safety at Argonne National Laboratory's Heavy Ion Research Facility (open access)

Radiological Safety at Argonne National Laboratory's Heavy Ion Research Facility

This paper discusses the radiological safety system to be employed at the Argonne Tandem-LINAC Accelerator System (ATLAS). The design parameters of ATLAS that affect safety have remained unchanged since ATLAS construction began in 1982. The specialized radiological safety considerations of ATLAS were discussed in 1982. This paper will present the details of the hardware, the administrative controls, and the radiation monitoring that will be in effect when beam is produced in April 1985.
Date: November 2, 1984
Creator: Cooke, R. H. & Wynveen, R. A.
System: The UNT Digital Library
Extragalactic origin of gamma-ray bursts. Revision 1 (open access)

Extragalactic origin of gamma-ray bursts. Revision 1

Detectors of gamma-rays carried by satellites and later by high-flying balloons showed the existence of events lasting from fifteen milliseconds to about a hundred seconds, arriving from all directions in space. A few hundred events have been observed in a little more than a decade. The energy of gamma-rays range from a few kilovolts to millions of volts. Recent evidence indicates that considerable energy may be carried at least in some cases even above 10 MeV. But the bulk of the energy appeared to be emitted between 100 and 200 keV. The observed intensities range between 10/sup -3/ and 10/sup -7/ ergs/cm/sup 2/. The simple facts about intensity distribution are compatible with two extreme assumptions but exclude intermediate hypotheses. Either the events occur in our own galaxy in a region smaller than the thickness of the galaxy or they are of extragalactic origin and come from distant galaxies. Practically all attempted explanations have made the former explanation which requires that a mass of approximately 10/sup 20/ grams impinges on a neutron star (assuming a near to 100% conversion of gravitational energy available on the surface of the neutron star or 10/sup 20/ ergs/gram into gamma-rays which, of course, is unrealistic). …
Date: November 2, 1984
Creator: Johnson, M. & Teller, E.
System: The UNT Digital Library
Neutron stars, strange stars, and the nuclear equation of state (open access)

Neutron stars, strange stars, and the nuclear equation of state

This article consists of three parts. In part one we review the present status of dense nuclear matter calculations, and introduce a representative collection of realistic nuclear equations of state which are derived for different assumptions about the physical behavior of dense matter (baryon population, pion condensation,.possible transition of baryon matter to quark matter). In part two we review recently performed non-rotating and rotating compact star calculations performed for these equations of state. The minimum stable rotational periods of compact stars, whose knowledge is of decisive importance for the interpretation of rapidly rotating pulsars, axe determined. For this purpose two different limits on stable rotation are studied: rotation at the general relativistic Kepler period (below which mass shedding at the star's equator sets in), and, secondly, rotation at the gravitational radiation-reaction instability (at which emission of gravitational waves set in which slows the star down). Part three of this article deals with the properties of hypothetical strange stars. Specifically we investigate the amount of nuclear solid crust that can be carried by a rotating strange star, and answer the question whether such objects can give rise to the observed phenomena of pulsar glitches, which is at the present time the …
Date: November 2, 1992
Creator: Weber, F. & Glendenning, N.K.
System: The UNT Digital Library
Fast pressure measurements for the TMX-U fusion experiment (open access)

Fast pressure measurements for the TMX-U fusion experiment

The pressure on the boundary of the Lawrence Livermore National Laboratory's (LLNL) tandem mirror (TMX-U) plasma experiment is difficult to trace for several reasons: (1) the TMX-U boundary is in the high vacuum range (10/sup -5/ to 10/sup -6/ Pa) and requires an ionization gauge; (2) the boundary includes high-energy neutral particles and radiation, so the gauge must be optically baffled from the plasma; (3) the gauge must be shielded from the magnetic flux density of 0.03 T; (4) maximum conductance to the gauge must be preserved so that the time response remains about 1 ms; (5) a fast electrical circuit is required to measure the small ion-current changes at a rate consistent with the geometrical and experimental time constant of 1 ms. We have developed solutions to these limitations, including fast ionization gauge (FIG) circuitry for the remote gauge operation and the CAMAC system for recording the pressure-time history in the TMX-U computer data base. We also give some examples of actual fast pressure histories during plasma operation.
Date: November 2, 1982
Creator: Hunt, A.L.; Coffield, F.E. & Pickles, W.L.
System: The UNT Digital Library
Marker evaluation of human breast and bladder cancers (open access)

Marker evaluation of human breast and bladder cancers

We are investigating multiple markers in human breast and bladder cancers. Our aim is to identify markers that are clinically relevant and that contribute to our understanding of the disease process in individual patients. Good markers accurately assess the malignant potential of a cancer in an individual patient. Thus, they help identify those cancers that will recur, and they may be used to predict more accurately time to recurrence, response to treatment, and overall prognosis. Therapy and patient management may then be optimized to the individual patient. Relevant markers reflect the underlying pathobiology of individual tumors. As a tissue undergoes transformation from benign to malignant, the cells lose their differentiated phenotype. As a generalization, the more the cellular phenotype, cellular proliferation and cellular genotype depart from normal, the more advanced is the tumor in its biological evolution and the more likely it is that the patient has a poor prognosis. We use three studies to illustrate our investigation of potential tumor markers. Breast cancers are labeled in vivo with 5-bromodeoxyuridine (BrdUrd) to give a direct measure of the tumor labeling index. Bladder cancers are analyzed immunocytochemically using an antibody against proliferation. Finally, the techniques of molecular genetics are used to …
Date: November 2, 1990
Creator: Mayall, B. H.; Carroll, P. R.; Chen, Ling-Chun; Cohen, M. B.; Goodson III, W. H.; Smith, H. S. et al.
System: The UNT Digital Library
Quality Assurance Program description, Defense Waste Processing Facility (DWPF). Revision 2 (open access)

Quality Assurance Program description, Defense Waste Processing Facility (DWPF). Revision 2

This document describes the Westinghouse Savannah River Company`s (WSRC) Quality Assurance Program for Defense Waste Processing at the Savannah River Site (SRS). WSRC is the operating contractor for the US Department of Energy (DOE) at the SRS. The following objectives are achieved through developing and implementing the Quality Assurance Program: (1) Ensure that the attainment of quality (in accomplishing defense high-level waste processing objectives at the SRS) is at a level commensurate with the government`s responsibility for protecting public health and safety, the environment, the public investment, and for efficiently and effectively using national resources. (2) Ensure that high-level waste from qualification and production activities conform to requirements defined by OCRWM. These activities include production processes, equipment, and services; and products that are planned, designed, procured, fabricated, installed, tested, operated, maintained, modified, or produced.
Date: November 2, 1992
Creator: Maslar, S. R.
System: The UNT Digital Library
Neutron stars, strange stars, and the nuclear equation of state (open access)

Neutron stars, strange stars, and the nuclear equation of state

This article consists of three parts. In part one we review the present status of dense nuclear matter calculations, and introduce a representative collection of realistic nuclear equations of state which are derived for different assumptions about the physical behavior of dense matter (baryon population, pion condensation,.possible transition of baryon matter to quark matter). In part two we review recently performed non-rotating and rotating compact star calculations performed for these equations of state. The minimum stable rotational periods of compact stars, whose knowledge is of decisive importance for the interpretation of rapidly rotating pulsars, axe determined. For this purpose two different limits on stable rotation are studied: rotation at the general relativistic Kepler period (below which mass shedding at the star`s equator sets in), and, secondly, rotation at the gravitational radiation-reaction instability (at which emission of gravitational waves set in which slows the star down). Part three of this article deals with the properties of hypothetical strange stars. Specifically we investigate the amount of nuclear solid crust that can be carried by a rotating strange star, and answer the question whether such objects can give rise to the observed phenomena of pulsar glitches, which is at the present time the …
Date: November 2, 1992
Creator: Weber, F. & Glendenning, N. K.
System: The UNT Digital Library
Parallel Computation of Integrated Electromagnetic, Thermal and Structural Effects for Accelerator Cavities (open access)

Parallel Computation of Integrated Electromagnetic, Thermal and Structural Effects for Accelerator Cavities

The successful operation of accelerator cavities has to satisfy both rf and mechanical requirements. It is highly desirable that electromagnetic, thermal and structural effects such as cavity wall heating and Lorentz force detuning in superconducting rf cavities can be addressed in an integrated analysis. Based on the SLAC parallel finite-element code infrastructure for electromagnetic modeling, a novel multi-physics analysis tool has been developed to include additional thermal and mechanical effects. The parallel computation enables virtual prototyping of accelerator cavities on computers, which would substantially reduce the cost and time of a design cycle. The multi-physics tool is applied to the LCLS rf gun for electromagnetic, thermal and structural analyses.
Date: November 2, 2011
Creator: Akcelik, V.; Candel, A. E.; Kabel, A. C.; Ko, K.; Lee, L.; Li, Z. et al.
System: The UNT Digital Library
CLIC RF High Power Production Testing Program (open access)

CLIC RF High Power Production Testing Program

The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production ({approx} 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented.
Date: November 2, 2011
Creator: Syratchev, I.; Riddone, G. & Tantawi, S. G.
System: The UNT Digital Library