Excitation of Accelerating Plasma Waves by Counter-propagating Laser Beams (open access)

Excitation of Accelerating Plasma Waves by Counter-propagating Laser Beams

Generation of accelerating plasma waves using two counter-propagating laser beams is considered. Colliding-beam accelerator requires two laser pulses: the long pump and the short timing beam. We emphasize the similarities and differences between the conventional laser wakefield accelerator and the colliding-beam accelerator (CBA). The highly nonlinear nature of the wake excitation is explained using both nonlinear optics and plasma physics concepts. Two regimes of CBA are considered: (i) the short-pulse regime, where the timing beam is shorter than the plasma period, and (ii) the parametric excitation regime, where the timing beam is longer than the plasma period. Possible future experiments are also outlined.
Date: August 30, 2001
Creator: Shvets, Gennady; Fisch, Nathaniel J. & Pukhov, and Alexander
Object Type: Report
System: The UNT Digital Library
Fabrication of Integrated Diffractive Micro-Optics for MEMS Applications (open access)

Fabrication of Integrated Diffractive Micro-Optics for MEMS Applications

We investigated the fabrication of integrated diffractive micro-optical features on MEMS structures for the purpose of motion detection. The process of producing the diffractive features and the MEMS structures by focused ion beam milling is described in detail, as is the ion beam sputtering process used to produce coatings on these structures. The diffractive features of the circular Fresnel zone plate (FZP) and spiral FZP were fabricated on MEMS structures and the relevant diffraction theory is discussed. The spiral FZP diffractive features produced well defined foci whose intensity varies with distance from the FZP. Observation of these intensity variations enabled us to detect the motion of the MEMS structure, and the resulting device was used to scan an IR image of a hot object.
Date: August 10, 2001
Creator: Senesac, L. R.
Object Type: Article
System: The UNT Digital Library
Borehole Data Package for Calendar Year 2000-2001 RCRA Wells at Single-Shell Tank Waste Management Area T (open access)

Borehole Data Package for Calendar Year 2000-2001 RCRA Wells at Single-Shell Tank Waste Management Area T

This document compiles information of the drilling and construction, well development, pump installation, and sediment and groundwater sampling applicable to the installation of five new RCRA wells in calendar year 2000 - 2001. Appendix A contains the Well Summary Sheets (as-built diagrams); the Well Construction Summary Reports, and the geologist's logs; Appendix B contains physical properties data; and Appendix C contains the borehole geophysical logs.
Date: August 15, 2001
Creator: Horton, Duane G & Hodges, Floyd N
Object Type: Report
System: The UNT Digital Library
Transient Inverse Calibration of Site-Wide Groundwater Model to Hanford Operational Impacts from 1943 to 1996--Alternative Conceptual Model Considering Interaction with Uppermost Basalt Confined Aquifer (open access)

Transient Inverse Calibration of Site-Wide Groundwater Model to Hanford Operational Impacts from 1943 to 1996--Alternative Conceptual Model Considering Interaction with Uppermost Basalt Confined Aquifer

The baseline three-dimensional transient inverse model for the estimation of site-wide scale flow parameters, including their uncertainties, using data on the transient behavior of the unconfined aquifer system over the entire historical period of Hanford operations, has been modified to account for the effects of basalt intercommunication between the Hanford unconfined aquifer and the underlying upper basalt confined aquifer. Both the baseline and alternative conceptual models (ACM-1) considered only the groundwater flow component and corresponding observational data in the 3-Dl transient inverse calibration efforts. Subsequent efforts will examine both groundwater flow and transport. Comparisons of goodness of fit measures and parameter estimation results for the ACM-1 transient inverse calibrated model with those from previous site-wide groundwater modeling efforts illustrate that the new 3-D transient inverse model approach will strengthen the technical defensibility of the final model(s) and provide the ability to incorporate uncertainty in predictions related to both conceptual model and parameter uncertainty.
Date: August 29, 2001
Creator: Vermeul, Vince R; Cole, Charles R; Bergeron, Marcel P; Thorne, Paul D & Wurstner, Signe K
Object Type: Report
System: The UNT Digital Library
NEUTRONIC STUDIES FOR AN INTEGRATED BEAM LINE SHIELD PACKAGE AT THE LUJAN CENTER (open access)

NEUTRONIC STUDIES FOR AN INTEGRATED BEAM LINE SHIELD PACKAGE AT THE LUJAN CENTER

None
Date: August 1, 2001
Creator: MUHRER, G.; RUSSELL, G. J. & PITCHER, E. J.
Object Type: Article
System: The UNT Digital Library
Carbon Dioxide for pH Control (open access)

Carbon Dioxide for pH Control

Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.
Date: August 16, 2001
Creator: Wagonner, R.C.
Object Type: Report
System: The UNT Digital Library
Post-Closure Monitoring Report for Corrective Action Unit 339: Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site, Nevada (open access)

Post-Closure Monitoring Report for Corrective Action Unit 339: Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site, Nevada

The Area 12 Fleet Operations Steam Cleaning site is located in the southeast portion of the Area 12 Camp at the Nevada Test Site (Figure 1). This site is identified in the Federal Facility Agreement and Consent Order (FFACO, 1996) as Corrective Action Site (CAS) 12-19-01 and is the only CAS assigned to Corrective Action Unit (CAU) 339. Post-closure sampling and inspection of the site were completed on March 23, 2001. Because of questionable representativeness and precision of the results, the site was resampled on June 12, 2001. Post-closure monitoring activities were scheduled biennially (every two years) in the Post-Closure Monitoring Plan provided in the December 1997 Closure Report for CAU 339: Area 12 Fleet Operations Steam Cleaning Discharge Area, Nevada Test Site (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1997). If after six years the rate of degradation appears to be so slow that the greatest concentration of total petroleum hydrocarbons (TPH) present at the site would not decay within 30 years of the site closure, the site will be reevaluated with consideration to enriching the impacted soil at the site to enhance the degradation process. A baseline for the site was established by sampling in 1997. Based …
Date: August 1, 2001
Creator: Urbon, A. T.
Object Type: Report
System: The UNT Digital Library
Consequences of return to power after a beam interruption in the blanket of an accelerator driven system. (open access)

Consequences of return to power after a beam interruption in the blanket of an accelerator driven system.

A sudden drop in power after a beam interruption leads to thermal fatigue effects in structural components in the blanket of an accelerator driven system. These thermal fatigue effects limit component lifetimes. A sudden return to power after a beam interruption can contribute significant additional thermal fatigue and greatly reduce component lifetimes. One obvious solution is a gradual return to power after a beam interruption. There are two potential problems with this solution. One problem involves interruptions that are longer than the thermal time constants of thin structural members but shorter than the time constants of thick structural members. In such a case, a gradual return to power reduces the additional thermal fatigue in the thin structural members but increases the thermal fatigue in thick structural members. Some compromise is necessary. The other problem is that for thick components with long thermal time constants a long, gradual return to power is required to minimize additional thermal fatigue. Such a slow return to power can reduce the utilization or the effective load factor of the system. Specific examples of beam interruptions with various assumptions on return to power are provided for a preliminary design for the blanket of the Accelerator Driven …
Date: August 9, 2001
Creator: Dunn, F.
Object Type: Article
System: The UNT Digital Library
A summary of generation IV non-classical power reactor concepts. (open access)

A summary of generation IV non-classical power reactor concepts.

The summary of this report are: (1) Despite many of the technology gaps and data uncertainties, there is no lack of innovation and revolutionary ideas in Non-Classical reactor concepts. (2) Several concepts such as gas/vapor core reactors meet or exceed Gen IV goals for sustainability, safety, and economy, and have potential for making significant inroads toward achieving the optimum utilization of nuclear energy. (3) Gas/vapor core reactors set the upper performance potential in sustainability and safety with no insurmountable technology challenge. (4) Evaluation of modular deployable concepts are underway. (5) Direct energy conversion and non-convective cooled nuclear reactor systems are eliminated from further evaluation process.
Date: August 1, 2001
Creator: Lewis, D.
Object Type: Article
System: The UNT Digital Library
D-Zero prospects for Run II physics (open access)

D-Zero prospects for Run II physics

Run II at the Tevatron will begin in the spring of 2001. With p{bar p} collisions at {radical}s = 2.0 TeV and an expected instantaneous luminosity of 2 x 10{sup 32} cm{sup -2} s{sup -1}, D0 is expected to collect an integrated luminosity of 2 fb{sup -1} in the first two years of running. The ongoing upgrade of the detector will allow the experiment not only to take full advantage of the high luminosity but will also allow for a rich B physics program at D0. In this paper the prospects for some important B physics measurements will be reviewed. These measurements include CP violation, B{sub s} mixing, rare B decays, and lifetimes and mass measurements of bottom particles such as the {Lambda}{sub b} and B{sub c}.
Date: August 24, 2001
Creator: Gutierrez, Gaston R
Object Type: Article
System: The UNT Digital Library
THE PROTOTYPE FUNDAMENTAL POWER COUPLER FOR THE SPALLATION NEUTRON SOURCE SUPERCONDUCTING CAVITIES: DESIGN AND INITIAL TEST RESULTS (open access)

THE PROTOTYPE FUNDAMENTAL POWER COUPLER FOR THE SPALLATION NEUTRON SOURCE SUPERCONDUCTING CAVITIES: DESIGN AND INITIAL TEST RESULTS

None
Date: August 1, 2001
Creator: WILSON, K. M.; CAMPISI, I. E. & AL, ET
Object Type: Article
System: The UNT Digital Library
Determination of 243Am in 244Cm by Gamma Spectroscopy (open access)

Determination of 243Am in 244Cm by Gamma Spectroscopy

Gamma spectroscopy with a high resolution Ge(Li) detector is used to determine 243Am by its 74.7-keV gamma transition in solutions containing much higher specific activities of other actinides and fission products. The method is well suited for analytical control of curium process steps because of its simplicity, speed and reliability. This paper discusses the study results.
Date: August 29, 2001
Creator: Wakat, M.A.
Object Type: Article
System: The UNT Digital Library
ORNL Nuclear Safety Research and Development Program Bimonthly Report for September-October 1968 (open access)

ORNL Nuclear Safety Research and Development Program Bimonthly Report for September-October 1968

The accomplishments during the months of September and October in the research and development program under way at ORNL as part of the U.S. Atomic Energy Commission's Nuclear Safety Program are summarized. Included in this report are work on various chemical reactions, as well as the release, characterization, and transport of fission products in containment systems under various accident conditions and on problems associated with the removal of these fission products from gas streams. Although most of this work is in general support of water-cooled power reactor technology, including LOFT and CSE programs, the work reflects the current safety problems, such as measurements of the prompt fuel element failure phenomena and the efficacy of containment spray and pool-suppression systems for fission-product removal. Several projects are also conducted in support of the high-temperature gas-cooled reactor (HTGR). Other major projects include fuel-transport safety investigations, a series cf discussion papers on various aspects of water-reactor technology, antiseismic design of nuclear facilities, and studies of primary piping and steel pressure-vessel technology. Experimental work relative to pressure-vessel technology includes investigations of the attachment of nozzles to shells and the implementation of joint AEC-PVRC programs on heavy-section steel technology and nuclear piping, pumps, and valves. Several …
Date: August 17, 2001
Creator: Cottrell, W. B.
Object Type: Report
System: The UNT Digital Library
Credit Documentation and the Mark 15 Subroutine (open access)

Credit Documentation and the Mark 15 Subroutine

This report documents the rewrite of the heat transfer subroutine. Part of the process of preparing the Mark 15 assembly for production operation is the development of thermal-hydraulic limits for the assembly. These limits require, among other items, the development of a Mark 15 assembly subroutine for the CREDIT code.
Date: August 16, 2001
Creator: McAllister, J.E.
Object Type: Report
System: The UNT Digital Library
Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint (open access)

Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of …
Date: August 6, 2001
Creator: Bharathan, D. & Nix, G.
Object Type: Article
System: The UNT Digital Library
Carbon Sequestration in Terrestrial Ecosystems: A Status Report on R and D Progress (open access)

Carbon Sequestration in Terrestrial Ecosystems: A Status Report on R and D Progress

Sequestration of carbon in terrestrial ecosystems is a low-cost option that may be available in the near-term to mitigate increasing atmospheric CO{sub 2} concentrations, while providing additional benefits. Storing carbon in terrestrial ecosystems can be achieved through maintenance of standing aboveground biomass, utilization of aboveground biomass in long-lived products, or protection of carbon (organic and inorganic) compounds present in soils. There are potential co-benefits from efforts to sequester carbon in terrestrial ecosystems. For example, long-lived valuable products (wood) are produced, erosion would be reduced, soil productivity could be improved through increased capacity to retain water and nutrients, and marginal lands could be improved and riparian ecosystems restored. Another unique feature of the terrestrial sequestration option is that it is the only option that is ''reversible'' should it become desirable or permissible. For example, forests that are created are thus investments which could be harvested should CO{sub 2} emissions be reduced in other ways to acceptable levels 50-100 years from now.
Date: August 30, 2001
Creator: Jacobs, G.K.
Object Type: Article
System: The UNT Digital Library
CHEMICAL APPLICATIONS OF INELASTIC X-RAY SCATTERING (open access)

CHEMICAL APPLICATIONS OF INELASTIC X-RAY SCATTERING

Inelastic x-ray scattering (IXS), complementary to other more established inelastic scattering probes, such as light scattering, electron scattering, and neutron scattering, is becoming an important experimental technique in the study of elementary excitations in condensed matters. Over the past decade, IXS with total energy resolution of few meV has been achieved, and is being used routinely in the study of phonon dispersions in solids and liquids as well as dynamics in disordered and biological systems. In the study of electronic excitations, IXS with total energy resolution on the order of 100 meV to 1 eV is gaining wider applications also. For example, IXS has been used to study collective excitations of valence electrons, single electron excitations of valence electrons, as well as core electron excitations. In comparison with the alternative scattering techniques mentioned above, IXS has several advantages. First, IXS probes the full momentum transfer range of the dielectric response of the sample, whereas light scattering is limited to very small momentum transfers, and electron scattering suffers the effects of multiple scattering at large momentum transfers. Second, since IXS measures the bulk properties of the sample it is not surface sensitive, therefore it does not require special preparation of the …
Date: August 2001
Creator: Hayashi, H.; Udagawa, Y.; Gillet, J. M.; Caliebe, W. A. & Kao, C. C.
Object Type: Book
System: The UNT Digital Library
SULFUR POLYMER ENCAPSULATION. (open access)

SULFUR POLYMER ENCAPSULATION.

Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ({approx}$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; …
Date: August 22, 2001
Creator: Kalb, P.
Object Type: Book
System: The UNT Digital Library
Preliminary studies of ATW multiple strata fuel cycle performance. (open access)

Preliminary studies of ATW multiple strata fuel cycle performance.

None
Date: August 10, 2001
Creator: Hill, R.N. & Taiwo, T.A.
Object Type: Article
System: The UNT Digital Library
2001 Gordon Research Conference on Archaea: [Ecology], Metabolism. Final progress report [agenda and attendee list] (open access)

2001 Gordon Research Conference on Archaea: [Ecology], Metabolism. Final progress report [agenda and attendee list]

The Gordon Research Conference on Archaea: Ecology, Metabolism [and Molecular Biology] was held at Proctor Academy, Andover, New Hampshire, August 5-10, 2001. The conference was attended by 135 participants. The attendees represented the spectrum of endeavor in this field, coming from academia, industry, and government laboratories, and included US and foreign scientists, senior researchers, young investigators, and students. Emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate discussion about the key issues in the field today. Session topics included the following: Ecology and genetic elements; Genomics and evolution; Ecology, genomes and gene regulation; Replication and recombination; Chromatin and transcription; Gene regulation; Post-transcription processing; Biochemistry and metabolism; Proteomics and protein structure; Metabolism and physiology. The featured speaker addressed the topic: ''Archaeal viruses, witnesses of prebiotic evolution?''
Date: August 10, 2001
Creator: Daniels, Charles
Object Type: Report
System: The UNT Digital Library
Foraging behavior of three passerines in mature bottomland hardwood forests during summer. (open access)

Foraging behavior of three passerines in mature bottomland hardwood forests during summer.

Attention has focused on forest management practices and the interactions between birds and their habitat, as a result of apparent declines in populations of many forest birds. Although avian diversity and abundance have been studied in various forest habitats, avian foraging behavior is less well known. Although there are published descriptions of avian foraging behaviors in the western United States descriptions from the southeastern United States are less common. This article reports on the foraging behavior of the White-eyed Vireo, Northern Parula, and Hooded Warbler in mature bottomland hardwood forests in South Carolina.
Date: August 1, 2001
Creator: Buffington, J., Matthew; Kilgo, John, C.; Sargent, Robert, A.; Miller, Karl, V. & Chapman, Brian, R.
Object Type: Article
System: The UNT Digital Library
2001 Gordon Research Conference on Quantum Control of Light and Matter. Final progress report [agenda and attendee list] (open access)

2001 Gordon Research Conference on Quantum Control of Light and Matter. Final progress report [agenda and attendee list]

The Gordon Research Conference on Quantum Control of Light and Matter [Quantum Control of Atomic and Molecular Motion] was held at Mount Holyoke College, South Hadley, Massachusetts, July 29 - August 3, 2001. The conference was attended by 119 participants. The attendees represented the spectrum of endeavor in this field, coming from academia, industry, and government laboratories, and included US and foreign scientists, senior researchers, young investigators, and students. Emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate discussion about the key issues in the field today. Session topics included the following: General perspectives, Phase control, Optimal control, Quantum information, Light manipulation and manipulation with light, Control in the condensed phase, Strong field control, Laser cooling and Bose-Einstein Condensate dynamics, and Control in the solid phase.
Date: August 3, 2001
Creator: Shapiro, Moshe
Object Type: Report
System: The UNT Digital Library
INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES (open access)

INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California, through the testing and application of advanced reservoir characterization and thermal production technologies. The hope is that successful application of these technologies will result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs, …
Date: August 8, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Computational Benchmark for Estimation of Reactivity Margin from Fission Products and Minor Actinides in PWR Burnup Credit (open access)

Computational Benchmark for Estimation of Reactivity Margin from Fission Products and Minor Actinides in PWR Burnup Credit

This report proposes and documents a computational benchmark problem for the estimation of the additional reactivity margin available in spent nuclear fuel (SNF) from fission products and minor actinides in a burnup-credit storage/transport environment, relative to SNF compositions containing only the major actinides. The benchmark problem/configuration is a generic burnup credit cask designed to hold 32 pressurized water reactor (PWR) assemblies. The purpose of this computational benchmark is to provide a reference configuration for the estimation of the additional reactivity margin, which is encouraged in the U.S. Nuclear Regulatory Commission (NRC) guidance for partial burnup credit (ISG8), and document reference estimations of the additional reactivity margin as a function of initial enrichment, burnup, and cooling time. Consequently, the geometry and material specifications are provided in sufficient detail to enable independent evaluations. Estimates of additional reactivity margin for this reference configuration may be compared to those of similar burnup-credit casks to provide an indication of the validity of design-specific estimates of fission-product margin. The reference solutions were generated with the SAS2H-depletion and CSAS25-criticality sequences of the SCALE 4.4a package. Although the SAS2H and CSAS25 sequences have been extensively validated elsewhere, the reference solutions are not directly or indirectly based on experimental …
Date: August 2, 2001
Creator: Wagner, J. C.
Object Type: Report
System: The UNT Digital Library