Proton Decay Studies of the Light Lu, Tm and Ho Isotopes (open access)

Proton Decay Studies of the Light Lu, Tm and Ho Isotopes

A double-sided Si-strip detector system has been installed and commissioned at the focal plane of the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility. The system can be used for heavy charged particle emission studies with half-lives as low as a few {micro}sec. In this paper the authors present identification and study of the decay properties of the five new proton emitters: {sup 140}Ho, {sup 141m}Ho, {sup 145}Tm, {sup 150m}Lu and {sup 151m}Lu.
Date: October 15, 1998
Creator: Akovali, Y.; Batchelder, J. C.; Bingham, C. R.; Davinson, T.; Ginter, T. N.; Gross, C. J. et al.
Object Type: Article
System: The UNT Digital Library
Systems and economic analysis of microalgae ponds for conversion of CO{sub 2} to biomass. Quarterly technical progress report, September 1993--December 1993 (open access)

Systems and economic analysis of microalgae ponds for conversion of CO{sub 2} to biomass. Quarterly technical progress report, September 1993--December 1993

This report provides an economic analysis and feasibility study for the utilization by microalgal systems of carbon dioxide generated from coal-fired power plants. The resulting biomass could be a fuel substitute for fossil fuels.
Date: January 15, 1994
Creator: Benemann, J. R. & Oswald, W. J.
Object Type: Report
System: The UNT Digital Library
The MINOS long-baseline experiment at Fermilab. (open access)

The MINOS long-baseline experiment at Fermilab.

The MINOS long-baseline experiment will search for neutrino oscillations by measuring an intense {nu}{sub {mu}} beam at the end of a 730 km flight path. The 10,000 ton MINOS far detector will utilize magnetized steel plates interleaved with track chambers to reconstruct event topologies and to measure the energies of the muons, hadrons and electromagnetic showers produced by neutrino interactions. The experiment is designed to detect {nu}{sub {mu}} {r_arrow} {nu}{sub {tau}} and {nu}{sub {mu}} {r_arrow} {nu}{sub e} oscillations with {Delta}m{sup 2} {ge} 0.001 eV{sup 2} and sin{sup 2}(2{theta}) {ge} 0.01. Any oscillation signal observed can be verified and studied by several independent tests: a near/far rate comparison, the NC/CC event ratio, the CC and NC event energy spectra, and the identification of electrons and {tau} leptons. The neutrino beam can be operated in both wide-band and narrow-band configurations, allowing the detailed study oscillation phenomena. The experiment is scheduled to begin operation in 2001.
Date: October 15, 1997
Creator: Ayres, D. S.
Object Type: Article
System: The UNT Digital Library
Braze Process Optimization Involving Conventional Metal/Ceramic Brazing with 50Au-50Cu Alloy (open access)

Braze Process Optimization Involving Conventional Metal/Ceramic Brazing with 50Au-50Cu Alloy

Numerous process variables can influence the robustness of conventional metal/ceramic brazing processes. Experience with brazing of hermetic vacuum components has identified the following parameters as influencing the outcome of hydrogen furnace brazed Kovar{trademark} to metallized alumina braze joints: (a) Mo-Mn metallization thickness, sinter fire temperature and porosity (b) Nil plate purity, thickness, and sinter firing conditions (c) peak process temperature, time above liquidus and (d) braze alloy washer thickness. ASTM F19 tensile buttons are being used to investigate the above parameters. The F19 geometry permits determination of both joint hermeticity and tensile strength. This presentation will focus on important lessons learned from the tensile button study: (A) the position of the Kovar{trademark} interlayer can influence the joint tensile strength achieved--namely, off-center interlayers can lead to residual stress development in the ceramic and degrade tensile strength values. Finite element analysis has been used to demonstrate the expected magnitude in strength degradation as a function of misalignment. (B) Time above liquidus (TAL) and peak temperature can influence the strength and alloying level of the resulting braze joint. Excessive TAL or peak temperatures can lead to overbraze conditions where all of the Ni plate is dissolved. (C) Metallize sinter fire processes can influence …
Date: December 15, 1999
Creator: MALIZIA JR.,LOUIS A.; MEREDITH,KEITH W.; APPEL,DANIEL B.; MONROE,SAUNDRA L.; BURCHETT,STEVEN N. & STEPHENS JR.,JOHN J.
Object Type: Article
System: The UNT Digital Library
Second line of defense program (open access)

Second line of defense program

Since the collapse of the Soviet Union, the prospect of nuclear materials entering the world market has become an ever-increasing threat. The Second Line of Defense (SLD) program was developed by the U.S. Department of Energy's (DOE) Nuclear Transfer and Supplier Policy Division (NN-43) to assist the Russian Federation State Customs Committee (RFSCC) in strengthening its capability to prevent illicit trafficking of nuclear materials across Russia's borders. The SLD program is a natural complement to the Material Protection Control and Accounting (MPC and A) program, which represents a first line of defense against the theft and diversion of nuclear materials. The SLD program is the first U.S.-Russian cooperative program to combat the illicit trafficking of nuclear and nuclear-related materials to would-be proliferators across Russia's borders.
Date: July 15, 1999
Creator: Cantut, L. & Thomas, L. L.
Object Type: Article
System: The UNT Digital Library
CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Quarterly technical progress report, July--September, 1995 (open access)

CO{sub 2} Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Quarterly technical progress report, July--September, 1995

The principal objective of the Central Vacuum Unit (CVU) CO{sub 2} Huff-n-Puff (H-n-P) project is to determine the feasibility and practicality of the technology in a waterflooded shallow shelf carbonate environment. The results of parametric simulation of the CO{sub 2} H-n-P process, coupled with the CVU reservoir characterization components will determine if this process is technically and economically feasible for field implementation. The technology transfer objective of the project is to disseminate the knowledge gained through an innovative plan in support of the Department of Energy`s (DOE) objective of increasing domestic oil production and deferring the abandonment of shallow shelf carbonate (SSC) reservoirs. Tasks associated with this objective are carried out in what is considered a timely effort for near-term goals.
Date: October 15, 1995
Creator: Cole, R.; Prieditis, J. & Vogt, J. Wehner, S.
Object Type: Report
System: The UNT Digital Library
Improved Oil Recovery in Fluvial Dominated Deltaic Reservoirs of Kansas - Near-Term (open access)

Improved Oil Recovery in Fluvial Dominated Deltaic Reservoirs of Kansas - Near-Term

The objective of this study is to study waterflood problems of the type found in Morrow sandstone. The major tasks undertaken are reservoir characterization and the development of a reservoir database; volumetric analysis to evaluate production performance; reservoir modeling; identification of operational problems; identification of unrecovered mobile oil and estimation of recovery factors; and identification of the most efficient and economical recovery process.
Date: April 15, 1998
Creator: Walton, A.; McCune, D.; Green, D. W.; Willhite, G. P.; Watney, L.; Reynolds, R. et al.
Object Type: Report
System: The UNT Digital Library
Experimental Demonstration of Guiding and Bending of Electromagnetic Waves in a Photonic Crystal (open access)

Experimental Demonstration of Guiding and Bending of Electromagnetic Waves in a Photonic Crystal

The routing and interconnection of optical signals through narrow channels and around sharp corners is important for large-scale all-optical circuit applications. A recent computational result suggests that photonic crystals may offer a novel way of achieving this goal by providing a mechanism for guiding light that is fundamentally different from traditional index guiding. Waveguiding in a photonic crystal, and near 100% transmission of electromagnetic waves around sharp 90o corners were observed experimentally. Bend- ing radii were made smaller than one wavelength.
Date: October 15, 1998
Creator: Chow, E.; Hietala, .; Joannopoulos, J.D.; Lin, S. & Villeneuve, P.R.
Object Type: Article
System: The UNT Digital Library
Design Optimization and Construction of the Thyratron/PFN Based Cost Model Modulator for the NLC (open access)

Design Optimization and Construction of the Thyratron/PFN Based Cost Model Modulator for the NLC

As design studies and various R and D efforts continue on Next Linear Collider (NLC) systems, much R and D work is being done on X-Band klystron development, and development of pulse modulators to drive these X-Band klystrons. A workshop on this subject was held at SLAC in June of 1998, and a follow-up workshop is scheduled at SLAC June 23-25, 1999. At the 1998 workshop, several avenues of R and D were proposed using solid state switching, induction LINAC principles, high voltage hard tubes, and a few more esoteric ideas. An optimized version of the conventional thyratron-PFN-pulse transformer modulator for which there is extensive operating experience is also a strong candidate for use in the NLC. Such a modulator is currently under construction for base line demonstration purposes. The performance of this ''Cost Model'' modulator will be compared to other developing technologies. Important parameters including initial capital cost, operating maintenance cost, reliability, maintainability, power efficiency, in addition to the usual operating parameters of pulse flatness, timing and pulse height jitter, etc. will be considered in the choice of a modulator design for the NLC. This paper updates the progress on this ''Cost Model'' modulator design and construction.
Date: March 15, 1999
Creator: Koontz, Roland F
Object Type: Report
System: The UNT Digital Library
Sorption and diffusion studies of Pu(IV) and Pu(V)-EDTA onto and through Hanford soil (open access)

Sorption and diffusion studies of Pu(IV) and Pu(V)-EDTA onto and through Hanford soil

Plutonium production at U.S. Department of Energy Hanford site has created massive amounts of radioactive and mixed wastes. Over 1.3 trillion liters of liquid waste have been discharged into the ground, the largest part of which has been absorbed by the upper soil layers with a small fraction migrating into the groundwater. Approximately 350 million liters of other low and high-level mixed wastes were stored in underground tanks between 1944 and 1980. These tanks contain organic materials that were introduced during the production and processing of plutonium, such as ethylenediametetraacetic acid (EDTA), tributyl phosphate, hexone, paraffin hydrocarbon and other minor organic and inorganic components. The quantity of EDTA is estimated to be 83 metric tons in the underground tanks. Several single-shell tanks are known or suspected to have leaked. It was reported that since 1995, approximately four million liters of mixed waste might have entered the soil beneath the single-shell tanks. This volume of waste is estimated to contain as much as one million curies of radioactivity.
Date: September 15, 1999
Creator: Allen, P G; Hakem, N L & Sylwester, E R
Object Type: Article
System: The UNT Digital Library
Issues and opportunities: beam simulations for heavy ion fusion (open access)

Issues and opportunities: beam simulations for heavy ion fusion

UCRL- JC- 134975 PREPRINT code offering 3- D, axisymmetric, and ''transverse slice'' (steady flow) geometries, with a hierarchy of models for the ''lattice'' of focusing, bending, and accelerating elements. Interactive and script- driven code steering is afforded through an interpreter interface. The code runs with good parallel scaling on the T3E. Detailed simulations of machine segments and of complete small experiments, as well as simplified full- system runs, have been carried out, partially benchmarking the code. A magnetoinductive model, with module impedance and multi- beam effects, is under study. experiments, including an injector scalable to multi- beam arrays, a high- current beam transport and acceleration experiment, and a scaled final- focusing experiment. These ''phase I'' projects are laying the groundwork for the next major step in HIF development, the Integrated Research Experiment (IRE). Simulations aimed directly at the IRE must enable us to: design a facility with maximum power on target at minimal cost; set requirements for hardware tolerances, beam steering, etc.; and evaluate proposed chamber propagation modes. Finally, simulations must enable us to study all issues which arise in the context of a fusion driver, and must facilitate the assessment of driver options. In all of this, maximum advantage …
Date: July 15, 1999
Creator: Friedman, A
Object Type: Article
System: The UNT Digital Library
Estimating radius of coverage of the Y-12 Plant criticality accident alarm system from experiments at the Los Alamos critical experiments facility (open access)

Estimating radius of coverage of the Y-12 Plant criticality accident alarm system from experiments at the Los Alamos critical experiments facility

None
Date: June 15, 1995
Creator: Baker, J. S. & Smith, J. A.
Object Type: Report
System: The UNT Digital Library
Exploiting the power of DSM and SMP clusters for parallel CFD (open access)

Exploiting the power of DSM and SMP clusters for parallel CFD

The new generation of powerful DSM and SMP cluster computers enables simulations of fluid dynamics at sufficient resolution to compute the complex nonlinear interactions of small-scale turbulent motions with a large-scale driving flow. With a new programming model of hierarchical shared memory multitasking, it is possible to exploit these new systems without disrupting the flow of small and medium-sized jobs that makes their existence possible.
Date: March 15, 1999
Creator: Anderson, S. E.; Cohen, R. H.; Curtis, B. C.; Dannevik, W. P.; Dimits, A. M.; Dinge, D. et al.
Object Type: Article
System: The UNT Digital Library
A sparse superlinearly convergent SQP with applications to two-dimensional shape optimization. (open access)

A sparse superlinearly convergent SQP with applications to two-dimensional shape optimization.

Discretization of optimal shape design problems leads to very large nonlinear optimization problems. For attaining maximum computational efficiency, a sequential quadratic programming (SQP) algorithm should achieve superlinear convergence while preserving sparsity and convexity of the resulting quadratic programs. Most classical SQP approaches violate at least one of the requirements. We show that, for a very large class of optimization problems, one can design SQP algorithms that satisfy all these three requirements. The improvements in computational efficiency are demonstrated for a cam design problem.
Date: April 15, 1998
Creator: Anitescu, M.
Object Type: Article
System: The UNT Digital Library
High-Level Waste Tanks Multi-Dimensional Contaminant Transport Model Development (open access)

High-Level Waste Tanks Multi-Dimensional Contaminant Transport Model Development

A suite of multi-dimensional computer models was developed to analyze the transport of residual contamination from high-level waste tanks through the subsurface to seeplines. Cases analyzed ranged from all the tanks in the F- and H-tank farms for an overall look; to the Tank 17-20 4-pack to study plume interaction; to individual tanks, such as Tank 17 and 20 for comparison with one-dimensional and modeling. The main purpose of this work was to develop and test the models, so only two relatively conservative contaminants were examined, Tc-99 and I-129. More complex analyses, such as solubility-limited species and radionuclides that head a decay chain were not addressed in this study.
Date: November 15, 1999
Creator: Collard, L.B.
Object Type: Report
System: The UNT Digital Library
Ball lens reflections by direct solution of Maxwell`s equations (open access)

Ball lens reflections by direct solution of Maxwell`s equations

Ball lenses are important for many applications. For example, ball lenses can be used to match the mode of a laser diode (LD) to a single mode fiber (SMF), essential for low-loss, high bit rate communication systems. Modeling the propagation of LD light through a ball lens presents a challenge due to the large angular divergence of the LD field (typically > 20{degrees} HWHM) and the subsequent significant effect of spherical aberration. Accurately calculating the reflected power is also difficult, but essential, since reflections as small as {minus}30 dB can destabilize the LID. A full-wave analysis of this system using, e.g., a finite-difference time-domain method is not practical because of the size of the ball lens, typically hundreds of wavelengths in diameter. Approximate scalar methods can give good results in some cases, but fail to calculate reflected power and miss polarization effects entirely. The authors` approach exploits the fact that the scattering of an arbitrary electromagnetic beam from a sphere is an exactly solvable problem. The scattering of a plane wave from a sphere is a classical problem which was solved by Mie in 1908. More recently, various workers have considered the scattering of a Gaussian beam from a sphere …
Date: February 15, 1995
Creator: Ratowsky, R. P.; Deri, R. J.; Kallman, J. S. & Trott, G.
Object Type: Article
System: The UNT Digital Library
Large eddy simulation and its implementation in the COMMIX code. (open access)

Large eddy simulation and its implementation in the COMMIX code.

Large eddy simulation (LES) is a numerical simulation method for turbulent flows and is derived by spatial averaging of the Navier-Stokes equations. In contrast with the Reynolds-averaged Navier-Stokes equations (RANS) method, LES is capable of calculating transient turbulent flows with greater accuracy. Application of LES to differing flows has given very encouraging results, as reported in the literature. In recent years, a dynamic LES model that presented even better results was proposed and applied to several flows. This report reviews the LES method and its implementation in the COMMIX code, which was developed at Argonne National Laboratory. As an example of the application of LES, the flow around a square prism is simulated, and some numerical results are presented. These results include a three-dimensional simulation that uses a code developed by one of the authors at the University of Notre Dame, and a two-dimensional simulation that uses the COMMIX code. The numerical results are compared with experimental data from the literature and are found to be in very good agreement.
Date: February 15, 1999
Creator: Sun, J. & Yu, D.-H.
Object Type: Report
System: The UNT Digital Library
Multiscale modeling of radiation effects in fcc and bcc metals (open access)

Multiscale modeling of radiation effects in fcc and bcc metals

The prospect of using computer simulations to calculate radiation-induced defect production and its influence on microstructure evolution and mechanical property changes during prolonged irradiation of nuclear materials has been a beckoning, yet elusive goal for many years. However, the enormous progress achieved in computational physics for calculating reliable, yet tractable interatomic potentials, coupled with vast improvements in computational power have brought this hope to near reality. In order to develop modeling and simulation tools for predicting the irradiation response of nuclear structural materials, models must be implemented and tested across all relevant length and time scales. We discuss the development and implementation of a modeling methodology that consists of the linkage and hierarchical use of ab initio electronic structure calculations, molecular dynamics (MD) simulations, and kinetic Monte Carlo (KMC) simulations. This methodology can describe length and time scales from nanometers to hundreds of microns and from picoseconds to years, respectively. The ideas are demonstrated in two applications. First, we describe simulations that describe the irradiation and subsequent isochronal annealing of Pb, a low melting point fcc metal, and compare the results to experiments. Second, we show how these methods can be used to investigate damage production and freely migrating defect …
Date: July 15, 1999
Creator: Alonso, E; Caturla, M; Diaz de la Rubia, T; Felter, T; Fluss, M; Perlado, J et al.
Object Type: Article
System: The UNT Digital Library
Thermal management in heavy vehicles : a review identifying issues and research requirements. (open access)

Thermal management in heavy vehicles : a review identifying issues and research requirements.

Thermal management in heavy vehicles is cross-cutting because it directly or indirectly affects engine performance, fuel economy, safety and reliability, engine/component life, driver comfort, materials selection, emissions, maintenance, and aerodynamics. It follows that thermal management is critical to the design of large (class 6-8) trucks, especially in optimizing for energy efficiency and emissions reduction. Heat rejection requirements are expected to increase, and it is industry's goal to develop new, innovative, high-performance cooling systems that occupy less space and are lightweight and cost-competitive. The state of the art in heavy vehicle thermal management is reviewed, and issues and research areas are identified.
Date: January 15, 1999
Creator: Wambsganss, M. W.
Object Type: Article
System: The UNT Digital Library
Deployment of an innovative thermally enhanced soil mixing process augmented with zero-valent iron. (open access)

Deployment of an innovative thermally enhanced soil mixing process augmented with zero-valent iron.

An innovative in-situ soil treatment process, referred to as soil mixing/thermally enhanced soil vapor extraction (SM/TESVE), was used to remediate the 317 Area of Argonne National Laboratory-East (i.e., Argonne), which is contaminated with volatile organic compounds (VOCs). Following the initial soil treatment, polishing was required to reduce residual concentrations of contaminants. A study of polishing methods was conducted. It determined that injecting metallic iron particles into the soil, in conjunction with soil mixing, would reduce residual VOC concentrations more effectively than the original conventional soil ventilation approach. After the effectiveness of iron injection was verified, it replaced the soil ventilation step. The modified process involved mixing the soil while hot air and steam were injected into it. Off-gases were captured in a hood over the treatment area. During this process, an iron slurry, consisting of up to 50% iron particles in water with guar gum added as a thickening agent, was injected and mixed into the soil by the mixing equipment. Approximately 6,246 m{sup 3} (8, 170 yd{sup 3}) of soil was treated during this project. Confirmatory samples were then collected. In these samples, VOC concentrations were usually reduced by more than 80%.
Date: January 15, 1999
Creator: Lynch, P. L.
Object Type: Article
System: The UNT Digital Library
Top quark mass measurement from t tbar dilepton events at linear collider (open access)

Top quark mass measurement from t tbar dilepton events at linear collider

None
Date: October 15, 1999
Creator: Yeh, J. Antos and G. P.
Object Type: Article
System: The UNT Digital Library
Integrated Approach Towards the Application of Horizontal Wells to Improve Waterflooding Performance (open access)

Integrated Approach Towards the Application of Horizontal Wells to Improve Waterflooding Performance

This final report describes the progress during the six year of the project on ''Integrated Approach Towards the Application of Horizontal Wells to Improve Waterflooding Performance.'' This report is funded under the Department of Energy's (DOE's) Class I program which is targeted towards improving the reservoir performance of mature oil fields located in fluvially-dominated deltaic deposits. The project involves using an integrated approach to characterize the reservoir followed by drilling of horizontal injection wells to improve production performance. The project was divided into two budget periods. In the first budget period, many modern technologies were used to develop a detailed reservoir management plan; whereas, in the second budget period, conventional data was used to develop a reservoir management plan. The idea was to determine the cost effectiveness of various technologies in improving the performance of mature oil fields.
Date: October 15, 1999
Creator: Kelkar, Mohan; Liner, Chris & Kerr, Dennis
Object Type: Report
System: The UNT Digital Library
Rapid asymmetric inflation and early cosmology in theories with sub-millimeter dimensions (open access)

Rapid asymmetric inflation and early cosmology in theories with sub-millimeter dimensions

It was recently pointed out that the fundamental Planck mass could be close to the TeV scale with the observed weakness of gravity at long distances being due the existence of new sub-millimeter spatial dimensions. In this picture the standard model fields are localized to a (3+1)-dimensional wall or ''3-brane''. We show that in such theories there exist attractive models of inflation that occur while the size of the new dimensions are still small. We show that it is easy to produce the required number of efoldings, and further that the density perturbations {delta}{rho}/{rho} as measured by COBE can be easily reproduced, both in overall magnitude and in their approximately scale-invariant spectrum. In the minimal approach, the inflaton field is just the moduli describing the size of the internal dimensions, the role of the inflationary potential being played by the stabilizing potential of the internal space. We show that under quite general conditions, the inflationary era is followed by an epoch of contraction of our world on the brane, while the internal dimensions slowly expand to their stabilization radius. We find a set of exact solutions which describe this behavior, generalizing the well-known Kasner solutions. During this phase, the production …
Date: March 15, 1999
Creator: Arkani-Hamed, Nima
Object Type: Report
System: The UNT Digital Library
Waste Package Project quarterly report, July 1, 1995--September 30, 1995 (open access)

Waste Package Project quarterly report, July 1, 1995--September 30, 1995

The following tasks are reported: overview and progress of nuclear waste package project and container design; nuclear waste container design considerations; structural investigation of multi purpose nuclear waste package canister; and design requirements of rock tunnel drift for long-term storage of high-level waste (faulted tunnel model study by photoelasticity/finite element analysis).
Date: November 15, 1995
Creator: Ladkany, S.G.
Object Type: Report
System: The UNT Digital Library