properties of low-index laser materials (open access)

properties of low-index laser materials

Measurements of n/sub 2/ for a large class of oxide and fluoride crystals and glasses have been made using 100-ps, 1.06-..mu..m laser pulses and time-resolved interferometry. Values of n/sub 2/ for various glasses are summarized.
Date: May 9, 1980
Creator: Weber, M. J.
Object Type: Report
System: The UNT Digital Library
Analytical methods of electrode design for a relativistic electron gun (open access)

Analytical methods of electrode design for a relativistic electron gun

The standard paraxial ray equation method for the design of electrodes for an electrostatically focused gun is extended to include relativistic effects and the effects of the beam's azimuthal magnetic field. Solutions for parallel and converging beams are obtained and the predicted currents are compared against those measured on the High Brightness Test Stand. 4 refs., 2 figs.
Date: May 9, 1985
Creator: Caporaso, G.J.; Cole, A.G. & Boyd, J.K.
Object Type: Article
System: The UNT Digital Library
Clad-thickness measurement using dual-frequency eddy current (open access)

Clad-thickness measurement using dual-frequency eddy current

None
Date: May 9, 1975
Creator: Hill, J. T.
Object Type: Report
System: The UNT Digital Library
Kaiser Engineers Railroad Tractive Effort Test, LOFT - A and M track (open access)

Kaiser Engineers Railroad Tractive Effort Test, LOFT - A and M track

This LTR contains the original results of the Railroad Locomotive Tractive Effort Test performed by Kaiser Engineers on July 29, 1965, using an existing 24-wheel 500-ton dolly and the existing shielded locomotive. The test was conducted to confirm calculations of the tractive effort required to move the LOFT dolly (MTA) through the four-rail high bay curve and the curve into the LOFT containment vessel.
Date: May 9, 1978
Creator: White, E.R.
Object Type: Report
System: The UNT Digital Library
Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations (open access)

Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations

A conceptual heat transfer loop and balance of plant design for the Pulse*Star Inertial Confinement Fusion Reactor has been investigated and results are presented. The Pulse*Star reaction vessel, a perforated steel bell jar approximately 11 m in diameter, is immersed in Li/sub 17/Pb/sub 83/ coolant which flows through the perforations and forms a 1.5 m thick plenum of droplets around an 8 m diameter inner chamber. The reactor and associated pumps, piping, and steam generators are contained within a 17 m diameter pool of Li/sub 17/Pb/sub 83/ coolant to minimize structural requirements and occupied space, resulting in reduced cost. Four parallel heat transfer loops with flow rates of 5.5 m/sup 3//s each are necessary to transfer 3300 MWt of power. The steam generator design was optimized by finding the most cost-effective combination of heat exchanger area and pumping power. Power balance calculations based on an improved electrical conversion efficiency revealed a net electrical output of 1260 MWe to the bus bar and a resulting net efficiency of 39%. Suggested balance-of-plant layouts are also presented.
Date: May 9, 1984
Creator: McDowell, M. W. & Murray, K. A.
Object Type: Report
System: The UNT Digital Library
Numerical simulation of an accelerator injector (open access)

Numerical simulation of an accelerator injector

Accelerator injector designs have been evaluated using two computer codes. The first code self consistently follows relativistic particles in two dimensions. Fields are obtained in the Darwin model which includes inductive effects. This code is used to study cathode emission and acceleration to full injector voltage. The second code transports a fixed segment of a beam along the remainder of the beam line. Using these two codes the effects of electrode configuration on emittance, beam quality and beam transport have been studied.
Date: May 9, 1985
Creator: Boyd, J.K.; Caporaso, G.J. & Cole, A.G.
Object Type: Article
System: The UNT Digital Library
Radioactive liquid wastes discharged to ground in the 200 Areas during 1976 (open access)

Radioactive liquid wastes discharged to ground in the 200 Areas during 1976

An overall summary is presented giving the radioactive liquid wastes discharged to ground during 1976 and since startup (for both total and decayed depositions) within the Production and Waste Management Division control zone (200 Area plateau). Overall summaries are also presented for 200 East Area and for 200 West Area. The data contain an estimate of the radioactivity discharged to individual ponds, cribs and specific retention sites within the Production and Waste Management Division during 1976 and from startup through December 31, 1976; an estimate of the decayed activities from startup through 1976; the location and reference drawings of each disposal site; and the usage dates of each disposal site. The estimates for the radioactivity discharged and for decayed activities dicharged from startup through December 31, 1976 are based upon Item 4 of the Bibliography. The volume of liquid discharged to the ponds also includes major nonradioactive streams. The wastes discharged during 1976 to each active disposal site are detailed on a month-to-month basis, along with the monthly maximum concentration and average concentration data. An estimate of the radioactivity discharged to each active site along with the remaining decayed activities is given.
Date: May 9, 1977
Creator: Mirabella, J.E.
Object Type: Report
System: The UNT Digital Library
Brightness measurements on the Livermore high brightness test stand (open access)

Brightness measurements on the Livermore high brightness test stand

Several techniques using small radius collimating pipes with and without axial magnetic fields to measure the brightness of an extracted 1 - 2 kA, 1 - 1.5 MeV electron beam will be described. The output beam of the High Brightness Test Stand as measured by one of these techniques is in excess of 2 x 10/sup 5/ amp/cm/sup 2//steradian. 5 refs., 4 figs.
Date: May 9, 1985
Creator: Caporaso, G.J. & Birx, D.L.
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for 132-D-2, 117-D Filter Building, Waste Site Reclassification Form 2005-024 (open access)

Remaining Sites Verification Package for 132-D-2, 117-D Filter Building, Waste Site Reclassification Form 2005-024

The 132-D-2 site (117-D Filter Building) and associated below-grade ductwork were decommissioned and demolished in two phases in 1985 and 1986, with a portion of the rubble left in situ beneath clean fill at least 1 m (3.3 ft) thick. Decommissioning included removal of contaminated equipment, including filters. Residual concentrations support future land uses that can be represented by a rural-residential scenario and pose no threat to groundwater or the Columbia River based on RESRAD modeling.
Date: May 9, 2006
Creator: Carlson, R. A.
Object Type: Report
System: The UNT Digital Library
Remaining Sites Verification Package for 132-D-3, 1608-D Effluent Pumping Station, Waste Site Reclassification Form 2005-033 (open access)

Remaining Sites Verification Package for 132-D-3, 1608-D Effluent Pumping Station, Waste Site Reclassification Form 2005-033

Decommissioning and demolition of the 132-D-3 site, 1608-D Effluent Pumping Station was performed in 1986. Decommissioning included removal of equipment, water, and sludge for disposal as radioactive waste. The at- and below-grade structure was demolished to at least 1 m below grade and the resulting rubble buried in situ. The area was backfilled to grade with at least 1 m of clean fill and contoured to the surrounding terrain. Residual concentrations support future land uses that can be represented by a rural-residential scenario and pose no threat to groundwater or the Columbia River based on RESRAD modeling.
Date: May 9, 2006
Creator: Carlson, R. A.
Object Type: Report
System: The UNT Digital Library
X-ray streak camera temporal resolution improvement using a longitudinal time-dependent field (open access)

X-ray streak camera temporal resolution improvement using a longitudinal time-dependent field

X-ray streak cameras (XSC) have been known to be one of the fastest detectors forultrafast X-ray science. A number of applications in material science, biochemistry, accelerator physics, require sub-picosecond resolution to study new phenomena. Inthis paper, we report on a new method which can potentially improve the temporal resolution of a streak camera down to 100 femtoseconds. This method uses a time-dependent acceleration field to lengthen the photoelectron bunch, significantlyimproving the time resolution as well as reducing the time dispersion caused byinitial energy spread and the effects fromthe space charge forces. A computer simulation of an XSC using this method shows significant improvement in the resolution.
Date: May 9, 2008
Creator: Qiang, Ji; Qiang, J.; Byrd, J.M.; Feng, J. & Huang, G.
Object Type: Article
System: The UNT Digital Library
EVALUATING EFFECTS OF NEPTUNIUM ON THE SRS METHOD FOR CONTROLLED POTENTIAL COULOMETRIC ASSAY OF PLUTONIUM IN SULFURIC ACID SUPPORTING ELECTROLYTE (open access)

EVALUATING EFFECTS OF NEPTUNIUM ON THE SRS METHOD FOR CONTROLLED POTENTIAL COULOMETRIC ASSAY OF PLUTONIUM IN SULFURIC ACID SUPPORTING ELECTROLYTE

A study of the impact of neptunium on the coulometric assay of plutonium in dilute sulfuric acid was performed. Weight aliquots of plutonium standard solutions were spiked with purified neptunium solution to evaluate plutonium measurement performance for aliquots with Pu:Np ratios of 50:1, 30:1, 20:1, 15:1, and 10:1. Weight aliquots of the pure plutonium standard solution were measured as controls. Routine plutonium instrument control standards were also measured. The presence of neptunium in plutonium aliquots significantly increases the random uncertainty associated with the plutonium coulometric measurement performed in accordance with ISO12183:2005.7 However, the presence of neptunium does not appear to degrade electrode performance and conditioning as aliquots of pure plutonium that were interspersed during the measurement of the mixed Pu:Np aliquots continued to achieve the historical short-term random uncertainty for the method. Lack of adequate control of the neptunium oxidation state is suspected to be the primary cause of the elevated measurement uncertainty and will be pursued in a future study.
Date: May 9, 2008
Creator: Holland, M & Sheldon Nichols, S
Object Type: Report
System: The UNT Digital Library
A Vlasov Solver for Longitudinal Dynamics in Beam Delivery Systems for X-Ray FELs (open access)

A Vlasov Solver for Longitudinal Dynamics in Beam Delivery Systems for X-Ray FELs

Direct numerical methods for solving the Vlasov equationoffer some advantages over macroparticle simulations, as they do notsuffer from the consequences of the statistical fluctuations inherent inusing a number of macroparticles smaller than thebunch population.Unfortunately these methods are more time-consuming and generallyconsidered impractical in a full 6D phase space. However, in alower-dimension phase space they may become attractive if the beamdynamics is sensitive to the presence of small charge-densityfluctuations and a high resolution is needed. In this paper we present a2D Vlasov solverfor studying the longitudinal beam dynamics insingle-pass systems of interest for X-Ray FELs, where characterization ofthe microbunching instability stemming from self-field amplified noise isof particular relevance.
Date: May 9, 2007
Creator: Venturini, Marco; Warnock, Robert & Zholents, Alexander
Object Type: Article
System: The UNT Digital Library
Testing Components of New Community Isopycnal Ocean Circulation Model (open access)

Testing Components of New Community Isopycnal Ocean Circulation Model

The ocean and atmosphere are both governed by the same physical laws and models of the two media have many similarities. However, there are critical differences that call for special methods to provide the best simulation. One of the most important difference is that the ocean is nearly opaque to radiation in the visible and infra-red part of the spectrum. For this reason water mass properties in the ocean are conserved along trajectories for long distances and for long periods of time. For this reason isopycnal coordinate models would seem to have a distinct advantage in simulating ocean circulation. In such a model the coordinate surfaces are aligned with the natural paths of near adiabatic, density conserving flow in the main thermocline. The difficulty with this approach is at the upper and lower boundaries of the ocean, which in general do not coincide with density surfaces. For this reason hybrid coordinate models were proposed by Bleck and Boudra (1981) in which Cartesian coordinates were used near the ocean surface and isopycnal coordinates were used in the main thermocline. This feature is now part of the HICOM model (Bleck, 2002).
Date: May 9, 2008
Creator: Bryan, Kirk
Object Type: Report
System: The UNT Digital Library
Elastic Scattering of Low-Energy Electrons byTetrahydrofuran (open access)

Elastic Scattering of Low-Energy Electrons byTetrahydrofuran

We present the results of ab initio calculations for elasticelectron scattering by tetrahydrofuran (THF) using the complex Kohnvariational method. We carried out fixed-nuclei calculations at theequilibrium geometry of the target molecule for incident electronenergies up to 20 eV. The calculated momentum transfer cross sectionsclearly reveal the presence of broad shape resonance behavior in the 8-10eV energy range, in agreement with recent experiments. The calculateddifferential cross sections at 20 eV, which include the effects of thelong-range electron-dipole interaction, are alsofound to be in agreementwith the most recent experimental findings.
Date: May 9, 2006
Creator: Trevisan, Cynthia S.; Orel, Ann E. & Rescigno, Thomas N.
Object Type: Article
System: The UNT Digital Library

Gamma-Ray Characterization of Soil Samples at the Pena Blanca Natural Analog, Chihuahua, Mexico

None
Date: May 9, 2006
Creator: French, D.; Anthony, E. & Goodell, P.
Object Type: Presentation
System: The UNT Digital Library
Characteristics of CoxTi1-xO2 thin films deposited by MOCVD (open access)

Characteristics of CoxTi1-xO2 thin films deposited by MOCVD

This paper deals with the growth and characterization of ferromagnetic cobalt doped TiO{sub 2} thin films deposited by liquid precursor metal organic chemical vapor deposition (MOCVD) using a new combination of the source materials Co(TMHD){sub 3}, tetrahydrofuran (THF), and titanium isopropoxide (TIP). An array of experiments reveals the intrinsic ferromagnetic nature of the grown films, and suggests that the magnetism is not generated by oxygen vacancies.
Date: May 9, 2008
Creator: McClure, A.; Kayani, A.; Idzerda, Y.U.; Arenholz, E. & Cruz, E.
Object Type: Article
System: The UNT Digital Library
Visualization Tools for Adaptive Mesh Refinement Data (open access)

Visualization Tools for Adaptive Mesh Refinement Data

Adaptive Mesh Refinement (AMR) is a highly effective method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations that must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR visualization research and tools and describe how VisIt currently handles AMR data.
Date: May 9, 2007
Creator: Weber, Gunther H.; Beckner, Vincent E.; Childs, Hank; Ligocki,Terry J.; Miller, Mark C.; Van Straalen, Brian et al.
Object Type: Article
System: The UNT Digital Library
FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL (open access)

FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL

Waste streams planned for generation by the Global Nuclear Energy Partnership (GNEP) and existing radioactive High Level Waste (HLW) streams containing organic compounds such as the Tank 48H waste stream at Savannah River Site have completed simulant and radioactive testing, respectfully, by Savannah River National Laboratory (SRNL). GNEP waste streams will include up to 53 wt% organic compounds and nitrates up to 56 wt%. Decomposition of high nitrate streams requires reducing conditions, e.g. provided by organic additives such as sugar or coal, to reduce NOX in the off-gas to N2 to meet Clean Air Act (CAA) standards during processing. Thus, organics will be present during the waste form stabilization process regardless of the GNEP processes utilized and exists in some of the high level radioactive waste tanks at Savannah River Site and Hanford Tank Farms, e.g. organics in the feed or organics used for nitrate destruction. Waste streams containing high organic concentrations cannot be stabilized with the existing HLW Best Developed Available Technology (BDAT) which is HLW vitrification (HLVIT) unless the organics are removed by pretreatment. The alternative waste stabilization pretreatment process of Fluidized Bed Steam Reforming (FBSR) operates at moderate temperatures (650-750 C) compared to vitrification (1150-1300 C). The …
Date: May 9, 2008
Creator: Williams, M
Object Type: Article
System: The UNT Digital Library
Renewables Portfolio Standards: A Factual Introduction toExperience from the United States (open access)

Renewables Portfolio Standards: A Factual Introduction toExperience from the United States

Renewables portfolio standards (RPS) have--since the late 1990s--proliferated at the state level in the United States. What began as a policy idea minted in California and first described in detail in the pages of the 'Electricity Journal' FPT has emerged as an important driver for renewable energy capacity additions in the United States. Over the years, articles in the 'Electricity Journal' have explored the RPS in more detail, identifying both its strengths and weaknesses. The present article provides an introduction to the history, concept, and design of the RPS, reviews early experience with the policy as applied at the state level, and provides a brief overview of Federal RPS proposals to date and the possible relationship between Federal and state RPS policies. Our purpose is to offer a factual introduction to the RPS, as applied and considered in the U.S. Though elements of state RPS design are summarized here, other publications provide a more thorough review of design lessons that emerge from that experience. In addition, the present article does not describe the results of economic analyses of Federal RPS proposals, though we do cite many of the analyses conducted by the U.S. DOE's Energy Information Administration (EIA).
Date: May 9, 2007
Creator: Wiser, R.; Namovicz, C.; Gielecki, M. & Smith, R.
Object Type: Article
System: The UNT Digital Library
Technology Review of Nondestructive Methods for Examination of Water Intrusion Areas on Hanford’s Double-Shell Waste Tanks (open access)

Technology Review of Nondestructive Methods for Examination of Water Intrusion Areas on Hanford’s Double-Shell Waste Tanks

Under a contract with CH2M Hill Hanford Group, Inc., PNNL has performed a review of the NDE technology and methods for examination of the concrete dome structure of Hanford’s double-shell tanks. The objective was to provide a matrix of methodologies that could be evaluated based on applicability, ease of deployment, and results that could provide information that could be used in the ongoing structural analysis of the tank dome. PNNL performed a technology evaluation with the objective of providing a critical literature review for all applicable technologies based on constraints provided by CH2M HILL. These constraints were not mandatory, but were desired. These constraints included performing the evaluation without removing any soil from the top of the tank, or if necessary, requesting that the hole diameter needed to gain access to evaluate the top of the tank structure to be no greater than approximately 12-in. in diameter. PNNL did not address the details of statistical sampling requirements as they depend on an unspecified risk tolerance. PNNL considered these during the technology evaluation and have reported the results in the remainder of this document. Many of the basic approaches to concrete inspection that were reviewed in previous efforts are still in …
Date: May 9, 2008
Creator: Watkins, Michael L. & Pardini, Allan F.
Object Type: Report
System: The UNT Digital Library
Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria (open access)

Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria

Calculations of non-inductive current drive typically have been used with model MHD equilibria which are independently generated from an assumed toroidal current profile or from a fit to an experiment. Such a method can lead to serious errors since the driven current can dramatically alter the equilibrium and changes in the equilibrium B-fields can dramatically alter the current drive. The latter effect is quite pronounced in LH current drive where the ray trajectories are sensitive to the local values of the magnetic shear and the density gradient. In order to overcome these problems, we have modified a LH simulation code to accommodate elongated plasmas with numerically generated equilibria. The new LH module has been added to the ACCOME code which solves for current drive by neutral beams, electric fields, and bootstrap effects in a self-consistent 2-D equilibrium. We briefly describe the model in the next section and then present results of a study of LH current drive in ITER. 2 refs., 6 figs., 2 tabs.
Date: May 9, 1989
Creator: Blackfield, D. T.; Devoto, R. S.; Fenstermacher, M. E.; Bonoli, P. T.; Porkolab, M. & Yugo, J.
Object Type: Article
System: The UNT Digital Library
Modular invariant gaugino condensation (open access)

Modular invariant gaugino condensation

The construction of effective supergravity lagrangians for gaugino condensation is reviewed and recent results are presented that are consistent with modular invariance and yield a positive definite potential of the noscale type. Possible implications for phenomenology are briefly discussed. 29 refs.
Date: May 9, 1991
Creator: Gaillard, M. K.
Object Type: Article
System: The UNT Digital Library
Nuclear hazardous waste cost control management (open access)

Nuclear hazardous waste cost control management

The effects of the waste content of glass waste forms on Savannah River high-level waste disposal costs are currently under study to adjust the glass frit content to optimize the glass waste loadings and therefore significantly reduce the overall waste disposal cost. Changes in waste content affect onsite Defense Waste Changes in waste contents affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over the 28 wt% waste loading of DWPF glass would reduce disposal costs by about $50 million for Savannah River wastes generated to the year 2000. Optimization of the glass waste forms to be produced in the SWPF is being supported by economic evaluations of the impact of the forms on waste disposal costs. Glass compositions are specified for acceptable melt processing and durability characteristics, with economic effects tracked by the number of waste canisters produced. This paper presents an evaluation of the effects of variations in waste content of the glass waste forms on the overall cost of the disposal, including offsite shipment and repository emplacement, of the Savannah River high-level wastes.
Date: May 9, 1991
Creator: Selg, R.A.
Object Type: Article
System: The UNT Digital Library