Preliminary demonstration of power beaming with non-coherent laser diode arrays (open access)

Preliminary demonstration of power beaming with non-coherent laser diode arrays

A preliminary demonstration of free-space electric power transmission has been conducted using non-coherent laser diode arrays as the transmitter and standard silicon photovoltaic cell arrays as the receiver. The transmitter assembly used a high-power-density array of infrared laser diode bars, water cooled via integrated microchannel heat sinks and focused by cylindrical microlenses. The diode array composite beam was refocused by a parabolic mirror over a 10 meter path, and received on a {approximately}15 x 25 cm panel of thinned single crystal high efficiency silicon solar cells. The maximum cell output obtained was several watts, and the cell output was used to drive a small motor. Due to operating constraints and unexpected effects, particularly the high nonuniformity of the output beam, both the distance and total received power in this demonstration were modest. However, the existing transmitter is capable of supplying several hundred watts of light output, with a projected received electric power in excess of 200 watts. The source radiance is approximately 5 x 10{sup 9} W/m{sup 2}-steradian. With the existing 20 cm aperture, useful power transmission over ranges to {approximately}100 meters should be achievable with a DC to DC efficiency of greater than 10%. Non-coherent sources of this type …
Date: February 26, 1999
Creator: Kare, J T; Militsky, F & Weisberg, A
System: The UNT Digital Library
Development of a 3D FEL code for the simulation of a high-gain harmonic generation experiment. (open access)

Development of a 3D FEL code for the simulation of a high-gain harmonic generation experiment.

Over the last few years, there has been a growing interest in self-amplified spontaneous emission (SASE) free-electron lasers (FELs) as a means for achieving a fourth-generation light source. In order to correctly and easily simulate the many configurations that have been suggested, such as multi-segmented wigglers and the method of high-gain harmonic generation, we have developed a robust three-dimensional code. The specifics of the code, the comparison to the linear theory as well as future plans will be presented.
Date: February 26, 1999
Creator: Biedron, S. G.
System: The UNT Digital Library
Water-soluble organophosphorus reagents for mineralization of heavy metals. (open access)

Water-soluble organophosphorus reagents for mineralization of heavy metals.

In this report, we have described the principal stages of a two-step process for the in-situ stabilization of actinide ions in the environment. The combination of cation exchange and mineralization appears likely to provide a long-term solution to environments contaminated with heavy metals. Relying on a naturally occurring sequestering agent has obvious potential advantages from a regulatory standpoint. There are additional aspects of this technology requiring further elucidation, including the demonstration of the effect of these treatment protocols on the geohydrology of soil columns, further examination of the influence of humates and other colloidal species on cation uptake, and microbiological studies of phytate hydrolysis. We have learned during the course of this investigation that phytic acid is potentially available in large quantities. In the US alone, phytic acid is produced at an annual rate of several hundred thousand metric tons as a byproduct of fermentation processes (11). This material presently is not isolated for use. Instead, most of the insoluble phyate (as phytin) is being recycled along with the other solid fermentation residues for animal feed. This material is in fact considered undesirable in animal feed. The details of possible separation processes for phytate from these residues would have to …
Date: February 26, 1999
Creator: Nash, K. L.
System: The UNT Digital Library
Second Symposium on ``Current trends in international fusion research: review and assessment`` Chairman`s summary of session (open access)

Second Symposium on ``Current trends in international fusion research: review and assessment`` Chairman`s summary of session

This session began with a keynote speech by B. Coppi of M.I.T., entitled: ``Physics of Fusion Burning Plasmas, Ignition, and Relevant Technology Issues.`` It continued with a second paper on the tokamak approach to fusion, presented by E. Mazzucato of the Princeton Plasma Physics Laboratory, entitled ``High Confinement Plasma Confinement Regime in TFTR Configurations with Reversed Magnetic Shear.`` The session continued with three talks discussing various aspects of the so-called ``Field Reversed Configuration`` (FRC), and concluded with a talk on a more general topic. The first of the three FRC papers, presented by J. Slough of the University of Washington, was entitled ``FRC Reactor for Deep Space Propulsion.`` This paper was followed by a paper by S. Goto of the Plasma Physics Laboratory of Osaka University in Japan, entitled ``Experimental Initiation of Field-Reversed Configuration (FRC) Toward Helium-3 Fusion.`` The third of the FRC papers, authored by H. Mimoto and Y. Tomito of the National Institute for Fusion Science, Nagoya, Japan, and presented by Y. Tomita was entitled ``Helium-3 Fusion Based on a Field-Reversed Configuration.`` The session was concluded with a paper presented by D. Ryutov of the Lawrence Livermore National Laboratory entitled: ``A User Facility for Research on Fusion Systems …
Date: February 26, 1998
Creator: Post, Richard F.
System: The UNT Digital Library
J-Integral Based Flaw Stability Analysis of Mild Steel Storage Tanks (open access)

J-Integral Based Flaw Stability Analysis of Mild Steel Storage Tanks

The J-integral fracture methodology was applied to evaluate the stability of postulated flaws in mild steel storage tanks. The material properties and the J-resistance (JR) curve were obtained from the archival A285 Grade B carbon steel test data. The J-integral calculation is based on the center-cracked panel solution of Shih and Hutchinson (1976). A curvature correction was applied to account for the cylindrical shell configuration. A finite element analysis of an arbitrary flaw in the storage tank geometry demonstrated that the approximate solution is adequate.
Date: February 26, 1999
Creator: Lam, P.S.
System: The UNT Digital Library
The Holifield Radioactive Ion Beams Facility (HRIBF) -- getting ready to do experiments (open access)

The Holifield Radioactive Ion Beams Facility (HRIBF) -- getting ready to do experiments

The conversion of the HHIRF facility to a Radioactive Ion Beam facility started in 1994. In this ISOL type facility the Cyclotron has been re-fitted as a driver providing high intensity proton beams which react with the target from which the radioactive products are extracted and then accelerated in the Tandem Electrostatic Accelerator to the desired energy for nuclear science studies. Facilities for nuclear physics experiments are at different stages of development: A Recoil Mass Spectrometer (RMS) with a complement of detectors at the focal plane and around the target is used primarily for nuclear structure studies. A large recoil separator combining velocity and momentum selection, with its complement of focal plane detectors, will be dedicated to measurements relevant to nuclear astrophysics. The Enge Split Pole spectrograph is being re-fitted for operation in a gas filled mode, making it a more versatile tool for nuclear reaction studies. With the new experimental equipment being commissioned and the prospects of running experiments with low intensity radioactive beams a significant effort to develop equipment for beam diagnostics is underway. Some of the efforts and results in developing beam diagnostic tools will be described.
Date: February 26, 1998
Creator: Shapira, D. & Lewis, T. A.
System: The UNT Digital Library
Probability Distribution Function Evolution for Binary Alloy Solidification (open access)

Probability Distribution Function Evolution for Binary Alloy Solidification

The thermally controlled solidification of a binary alloy, nucleated at isolated sites, is described by the evolution of a probability distribution function, whose variables include grain size and distance to nearest neighbor, together with descriptors of shape, orientation, and such material properties as orientation of nonisotropic elastic modulus and coefficient of thermal expansion. The relevant Liouville equation is described and coupled with global equations for energy and solute transport. Applications are discussed for problems concerning nucleation and impingement and the consequences for final size and size distribution. The goal of this analysis is to characterize the grain structure of the solidified casting and to enable the description of its probable response to thermal treatment, machining, and the imposition of mechanical insults.
Date: February 26, 1999
Creator: Steinzig, M. L. & Harlow, F. H.
System: The UNT Digital Library
Charge Transfer Experiment (open access)

Charge Transfer Experiment

Low energy charge transfer is an important process in plasmas where multicharged ions and neutral atoms or molecules can exist at eV/amu energies and below. At eV/amu collision energies there are no scaling laws to characterize the charge transfer cross section and both theory and experiment are difficult. The capabilities of current experimental techniques used to measure low energy total and state-selective cross sections are discussed.
Date: February 26, 2001
Creator: Havener, C. C.
System: The UNT Digital Library
Buildings in a Test Tube: Validation of the Short-Term Energy Monitoring (STEM) Method (Preprint) (open access)

Buildings in a Test Tube: Validation of the Short-Term Energy Monitoring (STEM) Method (Preprint)

This paper is extracted from a full-length technical report that presents a detailed analysis of the differences in thermal performance between the SIP and frame units and describes the validation of the STEM method.
Date: February 26, 2001
Creator: Judkoff, R.; Balcomb, J.D. (National Renewable Energy Laboratory); Barker, G.; Hancock, E. (Mountain Energy Partnership) & Subbarao, K.
System: The UNT Digital Library
Performance of the GRETA Prototype Detectors (open access)

Performance of the GRETA Prototype Detectors

None
Date: February 26, 2000
Creator: Vetter, K.; Kuhn, A.; Lee, I.Y.; Clark, R.; Cromaz, M.; Deleplanque, M. et al.
System: The UNT Digital Library
Critical current variation of Rutherford cable of Bi-2212 in high magnetic fields with transverse stress (open access)

Critical current variation of Rutherford cable of Bi-2212 in high magnetic fields with transverse stress

None
Date: February 26, 2000
Creator: Dietderich, Daniel R.; Hasegawa, T.; Aoki, Y. & Scanlan, Ronald M.
System: The UNT Digital Library
Control of the heavy-ion beam line gas pressure and density in the HYLIFE thick-liquid chamber (open access)

Control of the heavy-ion beam line gas pressure and density in the HYLIFE thick-liquid chamber

Controlling the density and pressure of the background gas in the beam lines of thick-liquid heavy-ion fusion chambers is of paramount importance for the beams to focus and propagate properly. Additionally, transport and deposition of debris material onto metal beam-tube surfaces may reduce the breakdown voltage and permit arcing with the beam. The strategy to control the gas pressure and the rate of debris deposition is twofold. First, the cool thick-liquid jet structures will mitigate the venting to the beam tubes. The ablation and venting of debris through thick-liquid structures must be modeled to predict the quantities of debris reaching the beam ports. TSUNAMI calculations have been performed to estimate the mass and energy flux histories at the entrance of the beam ports in a 9x9 HYLIFE pocket geometry. Secondly, additional renewable shielding will be interposed in the beam tubes themselves. Thick-liquid vortexes are planned to coat the inside of the beam tubes and provide a quasi-continuous protection of the beam-tube walls up to the final focus magnets. A three-component molten salt, flinabe, with a low melting temperature and vapor pressure, has been identified as a candidate liquid for the vortexes. The use of flinabe may actually eliminate the necessity …
Date: February 26, 2002
Creator: Debonnel, Christophe D.; Fukuda, Grant T.; Bardet, Philippe M. & Peterson, Per F.
System: The UNT Digital Library
Performance of the RNG and two-layer k-{var_epsilon} models in the simulation of LWR fuel-bundle flows. (open access)

Performance of the RNG and two-layer k-{var_epsilon} models in the simulation of LWR fuel-bundle flows.

None
Date: February 26, 2002
Creator: Tzanos, C. P.
System: The UNT Digital Library
Evaluation of pipe whip impacts on neighboring piping and walls of the Ignalina nuclear power plant. (open access)

Evaluation of pipe whip impacts on neighboring piping and walls of the Ignalina nuclear power plant.

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. Therefore, two cases are investigated: GDH impact on an adjacent GDH and its attached piping; and GDH impact on an adjacent reinforced concrete wall. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material characteristics. The results of the study indicate that a whipping GDH pipe would not significantly damage adjacent walls or piping and would not result in a propagation of pipe failures.
Date: February 26, 2002
Creator: Dundulis, G.; Kulak, R.F.; Marchertas, A.; Narvydas, E.; Petri, M.C. & Uspusas, E.
System: The UNT Digital Library
Direct contact heat exchange interfacial phenomena for liquid metal reactors : Part I - heat transfer. (open access)

Direct contact heat exchange interfacial phenomena for liquid metal reactors : Part I - heat transfer.

Experiments on direct-contact heat exchange between molten metal and water for steam production were conducted. These experiments involved the injection of water into molten lead-bismuth eutectic for heat transfer measurements in a 1-D geometry. Based on the initial results of the experiments, the effects of the water flow rate and the molten metal superheat (temperature difference between molten metal and saturated water) on the volumetric heat transfer coefficient were discussed.
Date: February 26, 2002
Creator: Cho, D. H.; Page, R. J.; Hurtault, D.; Abdulla, S.; Liu, X.; Anderson, M. H. et al.
System: The UNT Digital Library
Comparison of Aerosol Properties Within and Above the ABL at the ARM Program's SGP Site (open access)

Comparison of Aerosol Properties Within and Above the ABL at the ARM Program's SGP Site

The goal of this study was to determine under what conditions, if any, measurements of aerosol properties made at the Earth's surface are representative of the aerosol properties within the column of air above the surface. This project used data from the Atmospheric Radiation Measurement (ARM) site at the Southern Great Plains (SGP) site (Stokes and Schwartz 1994), which is one of the only locations in the world where ground-based and in situ airborne measurements of atmospheric aerosol are made on a routine basis. All flight legs in the one-year period from March 2000 to March 2001 were categorized as either within or above the atmospheric boundary layer (ABL) using an objective mixing height determination technique. The correlations between the aerosol properties measured at the surface and those measured within and above the ABL were then computed. The conclusion of this comparison is that the aerosol extensive properties (those that depend upon the amount of aerosol that is present in the atmosphere, i.e., either the number or mass concentrations), and intensive properties (those that do not depend upon the amount of aerosol present) measured at the surface are representative of values within the ABL, but not within the free atmosphere.
Date: February 26, 2002
Creator: Monache, L. D.; Perry, K. D. & Cederwall, R. T.
System: The UNT Digital Library
ENHS : the encapsulated nuclear heat source - a nuclear energy concept for emerging worldwide energy markets. (open access)

ENHS : the encapsulated nuclear heat source - a nuclear energy concept for emerging worldwide energy markets.

A market analysis is presented which delineates client needs and potential market size for small turnkey nuclear power plants with full fuel cycle services. The features of the Encapsulated Nuclear Heat Source (ENHS) which is targeted for this market are listed, and the status of evaluation of technological viability is summarized.
Date: February 26, 2002
Creator: Wade, D. C.; Feldman, E.; Sienicki, J.; Sofu, T.; Brown, N. W.; Hossain, Q. et al.
System: The UNT Digital Library
Need for multiple approaches in collaborative software development. (open access)

Need for multiple approaches in collaborative software development.

The need to share software and reintegrate it into new applications presents a difficult but important challenge. Component-based development as an approach to this problem is receiving much attention in professional journals and academic curricula. However, there are many other approaches to collaborative software development that might be more appropriate. This paper reviews a few of these approaches and discusses criteria for the conditions and contexts in which these alternative approaches might be more appropriate. This paper complements the discussion of context-based development team organizations and processes. Examples from a small development team that interacts with a larger professional community are analyzed.
Date: February 26, 2002
Creator: LePoire, D. J.
System: The UNT Digital Library
Application of seismic isolation to the STAR-LM reactor. (open access)

Application of seismic isolation to the STAR-LM reactor.

None
Date: February 26, 2002
Creator: Kulak, R.F. & Yoo, B.
System: The UNT Digital Library
Autonomous load following and operational aspects of the STAR-LM HLMC natural convection reactor. (open access)

Autonomous load following and operational aspects of the STAR-LM HLMC natural convection reactor.

None
Date: February 26, 2002
Creator: Sienicki, J. J. & Petkov, P. V.
System: The UNT Digital Library
STAR - H2 : the secure transportable autonomous reactor for hydrogen production and desalinization. (open access)

STAR - H2 : the secure transportable autonomous reactor for hydrogen production and desalinization.

The Secure Transportable Autonomous Reactor for Hydrogen production is a modular fast reactor intended for the mid 21st century energy market wherein electricity and hydrogen are employed as complementary energy carriers and nuclear energy contributes to sustainable energy supply based on full transuranic recycle in a passively safe, environmentally friendly and proliferation-resistant manner suitable for widespread worldwide deployment.
Date: February 26, 2002
Creator: Wade, D.C.; Doctor, R. & Peddicord, K.L.
System: The UNT Digital Library
Rare kaon decays (open access)

Rare kaon decays

The subject of rare and ultra-rare kaons decays is very active at this time with 8 experiments from 4 labs reporting new results recently and 6 new experiments recently approved. The physics topics under study include flavor changing neutral currents (FCNC), measurements of direct and indirect CP violation and searches for lepton flavor violation (LFV). These measurements are all characterized by very high sensitivities, studying modes with branching ratios in the 10{sup -7}--10{sup -12} range with single event sensitivities approaching 10{sup -12}. This is a region of sensitivity beyond the reach of charm and B experiment, at least for now. The development of beams with fluxes well above 1MHz of kaon decays enable these experiments. In this paper the author covers some of the important new results and the goals for the new experiments.
Date: February 26, 2002
Creator: Cooper, Peter S.
System: The UNT Digital Library
Experiment to measure the electron cloud at BEPC. (open access)

Experiment to measure the electron cloud at BEPC.

Many experiments on photoelectron instability (PEI) have been carried out at the Beijing Electron Positron Collider (BEPC) in IHEP, China, in collaboration with KEK[1]. Simulations on the PEI with a physical model give qualitative agreements with the observations at both BEPC and KEK-B. Based on the detectors at Advanced Photon Source (APS), ANL, a specially-constructed detector was installed at the BEPC. It is hoped to obtain realistic values for the photoelectron (PE) and secondary electron yields as well as the energy spectrum of the electron cloud through the direct measurements of the properties of the PE cloud for both stable and unstable beams. In this paper, the experimental results at the BEPC are presented after the description of the instrumentation, and some discussions are followed afterwards.
Date: February 26, 2002
Creator: Guo, Z. Y.; Qin, Q.; Cao, J. S.; Huang, H.; Ma, L.; Wang, J. Q. et al.
System: The UNT Digital Library
Building 7602 Decontamination and Decommissioning for Reuse by Spallation Neutron Source (open access)

Building 7602 Decontamination and Decommissioning for Reuse by Spallation Neutron Source

Building 7602 at the Oak Ridge National Laboratory (ORNL) was constructed in 1963 as a Reactor Service Building for the Experimental Gas-Cooled Reactor; the reactor was never fueled or operated, and the project was terminated in 1965. Significant building modifications were performed during the late 1970s and early 1980s. Beginning in 1984, separation processes and equipment development and testing were initiated for the Consolidated Fuel Reprocessing Program (CFRP). The principal materials used in the processes were depleted and natural uranium, nitric acid, and organic solvents. CFRP operations continued until 1994 when the program was discontinued and the facility declared surplus to the U.S. Department of Energy (DOE). Systems and equipment were shut down; feed and waste materials were removed; and process fluids, chemicals, and uranium were drained and flushed from systems. This paper will present an overview of the Building 7602 D&D activities, final radiological survey , facility modifications, and project interfaces.
Date: February 26, 2002
Creator: Brill, A.; Berger, J.; Kelsey, A. & Plummer, K.
System: The UNT Digital Library