Analysis of neon soft x-ray spectra from short-pulse laser-produced plasmas (open access)

Analysis of neon soft x-ray spectra from short-pulse laser-produced plasmas

We report preliminary results from the analysis of streaked soft x-ray neon spectra obtained from the interaction of a picosecond Nd:glass laser with a gas jet target. In these experiments streaked spectra show prompt harmonic emission followed by longer time duration soft x-ray line emission. The majority of the line emission observed was found to originate from Li- and Be-like Ne and the major transitions in the observed spectra have been identified. Li-like emission lines were observed to decay faster in time than Be-like transitions, suggesting that recombination is taking place. Line ratios of n=4-2 and n=3-2 transitions supported the view that these lines were optically thin and thick, respectively. The time history of Li-like Ne 2p-4d and 2p-3d lines is in good agreement with a simple adiabatic expansion model coupled to a time dependent collisional-radiative code. Further x-ray spectroscopic analysis is underway which is aimed at diagnosing plasma conditions and assessing the potential of this recombining neon plasma as a quasi-steady-state recombination x-ray laser medium.
Date: April 1, 1993
Creator: Abare, A. C.; Keane, C. J.; Crane, J. K.; DaSilva, L. B.; Lee, R. W.; Perry, M. D. et al.
Object Type: Article
System: The UNT Digital Library
Comparison of a constraint directed search to a genetic algorithm in a scheduling application (open access)

Comparison of a constraint directed search to a genetic algorithm in a scheduling application

Scheduling plutonium containers for blending is a time-intensive operation. Several constraints must be taken into account; including the number of containers in a dissolver run, the size of each dissolver run, and the size and target purity of the blended mixture formed from these runs. Two types of algorithms have been used to solve this problem: a constraint directed search and a genetic algorithm. This paper discusses the implementation of these two different approaches to the problem and the strengths and weaknesses of each algorithm.
Date: April 1, 1993
Creator: Abbott, L.
Object Type: Article
System: The UNT Digital Library
Multiphoton physics with x-rays: Two photon K-shell ionization of chlorine (open access)

Multiphoton physics with x-rays: Two photon K-shell ionization of chlorine

A calculation of the two X-ray K-shell photoionization cross section of chlorine will be presented and the feasibility of an experiment will be discussed.
Date: April 1, 1993
Creator: Abdallah, J.; Collins, L. A.; Csanak, G.; Kyrala, G. A. & Schappert, G. T.
Object Type: Article
System: The UNT Digital Library
The role of catalyst precursor anions in coal gasification. Fifth quarterly report (open access)

The role of catalyst precursor anions in coal gasification. Fifth quarterly report

The aims of the proposed project are to enrich our understanding of the roles of various aqueous soluble catalyst precursor anions on the surface electrical properties of coal and to ascertain the influence of the surface charge on the adsorption, dispersion, and activities of calcium and potassium. These goals will be achieved by impregnating a demineralized North Dakota lignite (PSOC 1482) with calcium or potassium catalyst precursors containing acetate (CH{sub 3}COO{sup {minus}}), chloride (Cl{sup {minus}}), nitrate (NO{sub 3}{sup {minus}}), sulfate (SO{sub 4}{sup 2{minus}}), and carbonate (CO{sub 3}{sup 2{minus}}) anions. Demineralization of the coal has been completed. In the past quarter, the effects of chloride anion on the surface charge properties of the demineralized coal has been studied using calcium or potassium chlorides. Like the compounds investigated previously, increasing anion concentrations produce less negative charge on the coal surface through the interaction of calcium or potassium ions with the surface. To date, Fourier transform infrared studied aimed at an understanding of the interaction between the metal ions (Ca{sup 2+} or {sup K+}) and the coal surface oxygen functionality has not been very informative, most probably due to the high infrared absorption by coal. For this reason, we have procured a resin, …
Date: April 1, 1993
Creator: Abotsi, G. M. K.
Object Type: Report
System: The UNT Digital Library
Application of a CdTe gamma-ray spectrometer to remote characterization of high-level radioactive waste tanks (open access)

Application of a CdTe gamma-ray spectrometer to remote characterization of high-level radioactive waste tanks

Small, shielded cadmium telluride (CdTe) semiconductor gamma-ray detectors have been used for in situ radiological characterization of underground high-level radioactive waste tanks. Remote measurements have been made in gamma radiation fields up to 700 R/h. Spectral data have been used to generate qualitative and quantitative radionuclide profiles of high-level radioactive waste tanks. Two electronic spectral enhancement techniques (pulse risetime discrimination and pulse risetime compensation) have been used in order to measure trace isotopes with photopeak energies greater than 662keV in the presence of large amounts of {sup 137}Cs. Spectral resolution of 1.5% for the {sup 137}Cs 662 keV photopeak has been obtained.
Date: April 1, 1993
Creator: Addleman, R. S.; Blewett, G. R.; Keele, B. D.; McClellan, C. S.; Subrahmanyam, V. B. & Troyer, G. L.
Object Type: Report
System: The UNT Digital Library
Modified Streamflows 1990 Level of Irrigation : Columbia River and Coastal Basins, 1928-1989. (open access)

Modified Streamflows 1990 Level of Irrigation : Columbia River and Coastal Basins, 1928-1989.

The annual operation plans described in the following sections require detailed system regulation computer model studies. These system regulation studies are necessary to evaluate potential new projects and to develop operational rule curves for the existing system of projects. The objective is to provide a basis for evaluating alternative system regulation scenarios. This provides essential input for optimizing the management of existing projects and planning future projects for the most beneficial use of the water supply and resources in the entire region. Historical streamflows per se are inadequate for system regulation studies because the pattern of observed flow has continually changed with each successive stage of irrigation and e development. The problem, therefore, is to adjust for past operation of storage projects and to determine the necessary adjustments that should be made to recorded flows to reflect current stages of irrigation development. Historical flows which have been adjusted to a common level of irrigation development by correcting for the effects of diversion demand, return flow, and change-of-contents and evaporation in upstream reservoirs and lakes are referred to as modified flows. This report describes the development of irrigation depletion adjustments and modified flows for the 1990 level of development for the …
Date: April 1, 1993
Creator: Administration, United States. Bonneville Power & Company, A. G. Crook
Object Type: Report
System: The UNT Digital Library
Method to evaluate steering and alignment algorithms for controlling emittance growth (open access)

Method to evaluate steering and alignment algorithms for controlling emittance growth

Future linear colliders will likely use sophisticated beam-based alignment and/or steering algorithms to control the growth of the beam emittance in the linac. In this paper, a mathematical framework is presented which simplifies the evaluation of the effectiveness of these algorithms. As an application, a quad alignment that uses beam data taken with the nominal linac optics, and with a scaled optics, is evaluated in terms of the dispersive emittance growth remaining after alignment.
Date: April 1, 1993
Creator: Adolphsen, C. & Raubenheimer, T.
Object Type: Article
System: The UNT Digital Library
The design and development of a single piece, sandwhich tube coldmass support post for the SSC Collider Dipole Magnets (open access)

The design and development of a single piece, sandwhich tube coldmass support post for the SSC Collider Dipole Magnets

This paper presents the design and development of the single piece, carbon/epoxy syntactic core sandwich tube support post concept for the 13-m and 15-m Collider Dipole Magnet (CDM). The engineering studies focus on balancing the structural and thermal requirements for the structure, and most importantly the implicit requirement of ``Designing for Producibility.`` Results from these studies, as well as the development program plan, will be presented.
Date: April 1, 1993
Creator: Ahmad, A. & Mehle, G.
Object Type: Article
System: The UNT Digital Library
The 1992 Polarized Light Source (open access)

The 1992 Polarized Light Source

We describe the Polarized Light Sources used at SLAC during the 1992 runs of the experiments SLD and E142.
Date: April 1, 1993
Creator: Alley, R.; Woods, M.; Browne, M.; Frisch, J. & Zolotorev, M.
Object Type: Article
System: The UNT Digital Library
MPS Vax monitor and control software architecture (open access)

MPS Vax monitor and control software architecture

The new Machine Protection System (MPS) now being tested at the SLAC Linear Collider (SLC) includes monitoring and controlling facilities integrated into the existing VAX control system. The actual machine protection is performed by VME micros which control the beam repetition rate on a pulse-by-pulse basis based on measurements from fault detectors. The VAX is used to control and configure the VME micros, configure custom CAMAC modules providing the fault detector inputs, monitor and report faults and system errors, update the SLC database, and interface with the user. The design goals of the VAX software include a database-driven system to allow configuration changes without code changes, use of a standard TCP/IP-based message service for communication, use of existing SLCNET micros for CAMAC configuration, security and verification features to prevent unauthorized access, error and alarm logging and display updates as quickly as possible, and use of touch panels and X-windows displays for the user interface.
Date: April 1, 1993
Creator: Allison, S.; Spencer, N.; Underwood, K.; VanOlst, D. & Zelanzy, M.
Object Type: Article
System: The UNT Digital Library
The Midwest Power PCFB demonstration projects: AHLSTROM PYROFLOW{reg_sign} first and second generation pressurized circulating fluidized bed (PCFB) technology (open access)

The Midwest Power PCFB demonstration projects: AHLSTROM PYROFLOW{reg_sign} first and second generation pressurized circulating fluidized bed (PCFB) technology

Midwest Power, Dairyland Power Cooperative, Pyropower Corporation (a subsidiary of Ahlstrom Pyropower Inc.), and Black & Veatch, have embarked on the demonstration of Clean Coal Technology (CCT) at Midwest Power`s Des Moines Energy Center (DMEC), in Pleasant Hill, Iowa. The DMEC-1 PCFB Demonstration Project was selected by the US Department of Energy for the demonstration of the First Generation Pressurized Circulating Fluidized Bed (PCFB) Technology. During Round 5 of the CCT Program, Midwest Power submitted a proposal for a second unit, to be known as DMEC-2. If selected by the DOE, the DMEC-2 unit will demonstrate Ahlstrom Pyropower`s Second Generation (Advanced) PCFB technology which will incorporate a topping combustor fired on coal derived gas generated in a PCFB carbonizer, to raise the firing temperature of the gas turbine and the total net plant efficiency. The First Generation PCFB technology has the capability to achieve 40--42% efficiency, the Second Generation technology can obtain an efficiency in the range of 44--47% net. This paper will provide a comparison of the commercial versions of the First and Second Generation PCFB systems, and the plans for demonstrating these systems for repowering and new plant installations during the late 1990`s and into the next century. …
Date: April 1, 1993
Creator: Ambrose, S.; Green, C. L.; Dryden, R. & Provol, S. J.
Object Type: Article
System: The UNT Digital Library
Parametric study of radionuclide characterization -- Low-level waste. Draft (open access)

Parametric study of radionuclide characterization -- Low-level waste. Draft

The criteria and guidance given in this addendum specifically address the classification of low-level waste at the Hanford Reservation into Category 1, Category 3, and Greater Than Category 3 (GTC3). These categories are developed based on the performance assessment (PA) being conducted for the Hanford Site. The radionuclides and their concentration for each category are listed in the revised Table 1-1 (Attachment 1). The information to classify the waste for US Department of Transportation (DOT) and to classify Transuranic (TRU)/ Non-TRU, Contact Handled (CH)/Remote Handled (RH) waste is given in WHC-EP-0063-3 (WHC 1991).
Date: April 1, 1993
Creator: Amir, S. J.
Object Type: Report
System: The UNT Digital Library
Reliability modeling of an engineered barrier system (open access)

Reliability modeling of an engineered barrier system

The Weibull distribution is widely used in reliability literature as a distribution of time to failure, as it allows for both increasing failure rate (IFR) and decreasing failure rate (DFR) models. It has also been used to develop models for an engineered barrier system (EBS), which is known to be one of the key components in a deep geological repository for high level radioactive waste (HLW). The EBS failure time can more realistically be modelled by an IFR distribution, since the failure rate for the EBS is not expected to decrease with time. In this paper, an IFR distribution is used to develop a reliability model for the EBS.
Date: April 1, 1993
Creator: Ananda, M. M. A.; Singh, A. K. & Flueck, J. A.
Object Type: Article
System: The UNT Digital Library
Material removal processes: Engineering mechanics consideration (open access)

Material removal processes: Engineering mechanics consideration

In the material removal process called machining, a layer of material of constant thickness is removed from the workpiece by a wedge-shaped tool that travels parallel to the workpiece at a preselected depth. Even though the speed of relative movement between workpiece and tool is low (typical 1--10 M/S), the strain-rates in the workpiece near the tool can be high, on the order of 10{sup 4}-10{sup 5} s{sup {minus}1}. When machining brittle materials or unlubricated ductile materials at low speed, the removed metal (or chip) will be discontinuous and made up of small fractured segments. On the other hand, when machining ductile material under lubricated conditions, the removed material forms a continuous coil. In this case, we can represent the material removal process as a steady-state process. In this presentation, we will restrict ourselves to orthogonal machining where the cutting edge is perpendicular to the relative motion-a situation also approximated by other material removal processes such as planing and broaching, and turning on a lathe.
Date: April 1, 1993
Creator: Anderson, C. A.
Object Type: Article
System: The UNT Digital Library
Valuing the salmon resource: Columbia River stocks under climate change and fishery enhancement (open access)

Valuing the salmon resource: Columbia River stocks under climate change and fishery enhancement

This paper represents an update to ongoing multidisciplinary research in the area of climate change and associated regional impacts to fisheries and economies. This work particularly deals with the total value of Columbia River salmon and the idea that fish have capital value, articulated here as spawning value. Earlier work dealt solely with the Yakima River spring chinook fishery`s response to climate change and fishery enhancement programs and the associated direct economic effects (Anderson et al. 1992). We have expanded our modeling attempts to examine similar impacts in the Grande Ronde River subbasin of the Columbia River basin, and added the summer steelhead stock to the analysis. Relatively recent developments and improvements in climate change modeling and fishery modeling enabled us to attempt such an endeavor.
Date: April 1, 1993
Creator: Anderson, D. M. & Scott, M. J.
Object Type: Article
System: The UNT Digital Library
Noble metal behavior during melting of simulated high-level nuclear waste glass feeds (open access)

Noble metal behavior during melting of simulated high-level nuclear waste glass feeds

Noble metals and their oxides can settle in waste glass melters and cause electrical shorting. Simulated waste feeds from Hanford, Savannah River, and Germany were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600{degrees}C--1000{degrees}C and examined by electron microscopy to determine shapes, sizes, and distribution of noble metal particles as a function of temperature. Individual noble metal particles and agglomerates of rhodium (Rh), ruthenium (RuO{sub 2}), and palladium (Pd), as well as their alloys, were seen. the majority of particles and agglomerates were generally less than 10 microns; however, large agglomerations (up to 1 mm) were found in the German feed. Detailed particle distribution and characterization was performed for a Hanford waste to provide input to computer modeling of particle settling in the melter.
Date: April 1, 1993
Creator: Anderson, L. D.; Dennis, T.; Elliott, M. L. & Hrma, P.
Object Type: Article
System: The UNT Digital Library
Waste glass melting stages (open access)

Waste glass melting stages

Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600[degrees]C--1000[degrees]C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied.
Date: April 1, 1993
Creator: Anderson, L. D.; Dennis, T.; Elliott, M. L. & Hrma, P.
Object Type: Article
System: The UNT Digital Library
Waste glass melting stages (open access)

Waste glass melting stages

Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600{degrees}C--1000{degrees}C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied.
Date: April 1, 1993
Creator: Anderson, L. D.; Dennis, T.; Elliott, M. L. & Hrma, P.
Object Type: Article
System: The UNT Digital Library
Temperature effects on failure thickness and deflagration-to-detonation transition in PBX 9502 and TATB (open access)

Temperature effects on failure thickness and deflagration-to-detonation transition in PBX 9502 and TATB

The deflagration-to-detonation (DDT) behavior of TATB has been investigated at high temperatures and severe confinement. comparison is made to other common explosives under similar confinement. TATB did not DDT under these conditions. The failure thickness of PBX 9502 at 250{degrees}C has also been determined. Two mm appears to be the limiting value at this temperature.
Date: April 1, 1993
Creator: Asay, B. W. & McAfee, J. B.
Object Type: Article
System: The UNT Digital Library
A matrix analysis of conjugate gradient algorithms (open access)

A matrix analysis of conjugate gradient algorithms

This paper explores the relationships between the conjugate gradient algorithms Orthodir, Orthomin, and Orthores. To facilitate this exploration, a matrix formulation for each algorithm is given. It is shown that Orthodir directly computes a Hessenberg matrix H{sub k} at step k. Orthores also computes a Hessenberg matrix, G{sub k}, which is similar to a Hessenberg matrix obtained from H{sub k} by perturbing its last column. (This perturbation vanishes at convergence.) Orthomin, on the other hand, computes a UL and LU factorization of the perturbed H{sub k} and G{sub k}, respectively. The breakdown of Orthomin and Orthores are interpreted in terms of these underlying matrix factorizations. A connection with Lanczos algorithms is also examined, as is the special case of B-normal(1) matrices (for which efficient three-term CG algorithms exist).
Date: April 1, 1993
Creator: Ashby, S. F. & Gutknecht, M. H.
Object Type: Article
System: The UNT Digital Library
Empirical distributions of radionuclides, from RWMIS data (open access)

Empirical distributions of radionuclides, from RWMIS data

The RWMIS data base gives data on each shipment of waste received at the Transuranic Storage Area, including the total volume of the shipment and the activity (Ci) of each nuclide in the shipment. This report assumes that the RWMIS numbers are correct, and considers the waste containers now retrievably stored at the Transuranic Storage Area. The total decay-corrected activities are summarized for several classes, such as for transuranic (TRU) waste and non-TRU waste, for {alpha}-emitters and {beta}/{gamma}-emitters, by waste originator and by current storage location. The total activity for each nuclide is also given. The empirical distributions are then given for a number of classes and individual nuclides, reflecting the variability between waste shipments. They are expressed in terms of mCi/cu-ft; for fissionable nuclides, the same information is also expressed in terms of mg/cu-ft; finally, the distribution is also given for the committed effective dose equivalent from inhalation, expressed in Mrem/cu-ft. The empirical distributions can be used for simulating the contents of a random waste container with a postulated volume. Examples are given illustrating the uses and limitations of the results.
Date: April 1, 1993
Creator: Atwood, C. L. & Schlafman, M. J.
Object Type: Report
System: The UNT Digital Library
Integration of rapid prototyping into design and manufacturing (open access)

Integration of rapid prototyping into design and manufacturing

The introduction of rapid prototyping machines into the market place promises to revolutionize the process of producing prototype parts with production-like quality. In the age of concurrent engineering and agile manufacturing, it is necessary to exploit applicable new technologies as soon as they become available. The driving force behind integrating these evolutionary processes into the design and manufacture of prototype parts is the need to reduce lead times and fabrication costs improve efficiency, and increase flexibility without sacrificing quality. Sandia Utilizes stereolithography and selective laser sintering capabilities to support internal design and manufacturing efforts. Stereolithography (SLA) is used in the design iteration process to produce proof-of-concept models, hands-on models for design reviews, fit check models, visual aids for manufacturing, and functional parts in assemblies. Selective laser sintering (SLS) is used to produce wax patterns for the lost wax process of investment casting in support of an internal Sandia National Laboratories program called FASTCAST which integrates experimental and computational technologies into the investment casting process. This presentation will provide a brief overview of the SLA and SLS processes and address our experiences with these technologies from the standpoints of application, accuracy, surface finish, and feature definition. Also presented will be several …
Date: April 1, 1993
Creator: Atwood, C. L.; McCarty, G. D. & Pardo, B. T.
Object Type: Article
System: The UNT Digital Library
Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications. Option 2 Program: Development and testing of zinc titanate sorbents (open access)

Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications. Option 2 Program: Development and testing of zinc titanate sorbents

One of the most advantageous configurations of the integrated gasification combined cycle (IGCC) power system is coupling it with a hot gas cleanup for the more efficient production of electric power in an environmentally acceptable manner. In conventional gasification cleanup systems, closely heat exchangers are necessary to cool down the fuel gases for cleaning, sometimes as low as 200--300{degree}F, and to reheat the gases prior to injection into the turbine. The result is significant losses in efficiency for the overall power cycle. High-temperature coal gas cleanup in the IGCC system can be operated near 1000{degree}F or higher, i.e., at conditions compatible with the gasifier and turbine components, resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for IGCC power systems in which mixed-metal oxides are currently being used as desulfurization sorbents. The objective of this contract is to identify and test fabrication methods and sorbent chemical compositions that enhance the long-term chemical reactivity and mechanical durability of zinc ferrite and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. Zinc ferrite was studied under the base program of this contract. In the next phase of this program novel sorbents, particularly zinc titanate-based sorbents, …
Date: April 1, 1993
Creator: Ayala, R. E.
Object Type: Report
System: The UNT Digital Library
Stochastic two-fluid model for relativistic heavy-ion collisions (open access)

Stochastic two-fluid model for relativistic heavy-ion collisions

A reduction of the relativistic Boltzmann-Langevin Equation (BLE), to a stochastic two-fluid model is presented, and transport coefficients associated with fluid dynamical variables are extracted. The approach is applied to investigate equilibration in a counter-streaming nuclear system.
Date: April 1, 1993
Creator: Ayik, S.; Ivanov, Y. B.; Russkikh, V. N. & Noerenberg, W.
Object Type: Article
System: The UNT Digital Library