Generating High-Brightness Light Ion Beams for Inertial Fusion Energy (open access)

Generating High-Brightness Light Ion Beams for Inertial Fusion Energy

Light ion beams may be the best option for an Inertial Fusion Energy (IFE) driver from the standpoint of ei%ciency, standoff, rep-rate operation and cost. This approach uses high-energy-density pulsed power to efficiently accelerate ions in one or two stages at fields of 0.5 to 1.0 GV/m to produce a medium energy (30 MeV), high-current (1 MA) beam of light ions, such as lithium. Ion beams provide the ability for medium distance transport (4 m) of the ions to the target, and standofl of the driver from high- yield implosions. Rep-rate operation of' high current ion sources has ako been demonstrated for industrial applications and couId be applied to IFE. Although (hese factors make light ions the best Iong-teml pulsed- power approach to IFE, light-ion research is being suspended this year in favor of a Z-pinch-driven approach which has the best opport lnity to most-rapidly achieve the U.S. Department of Energy sponsor's goal of high-yield fusion. This paper will summarize the status and most recent results of the light-ion beam program at Sandia National Laboratories (SNL), and document the prospects of light ions for future IFE driver development.
Date: October 22, 1998
Creator: Adams, R. G.; Bailey, J. E.; Cuneno, M. E.; Desjarlais, M. P.; Filuk, A. B.; Hanson, D. L. et al.
Object Type: Article
System: The UNT Digital Library
Coulomb clusters in RETRAP (open access)

Coulomb clusters in RETRAP

Storage rings and Penning traps are being used to study ions in their highest charge states. Both devices must have the capability for ion cooling in order to perform high precision measurements such as mass spectrometry and laser spectroscopy. This is accomplished in storage rings in a merged beam arrangement where a cold electron beam moves at the speed of the ions. In RETRAP, a Penning trap located at Lawrence Livermore National Laboratory, a sympathetic laser/ion cooling scheme has been implemented. In a first step, singly charged beryllium ions are cooled electronically by a tuned circuit and optically by a laser. Then hot, highly charged ions are merged into the cold Be plasma. By collisions, their kinetic energy is reduced to the temperature of the Be plasma. First experiments indicate that the highly charged ions form a strongly coupled plasma with a Coulomb coupling parameter.
Date: October 22, 1998
Creator: Beck, B. R.; Church, D. A.; Gruber, L.; Holder, J. P.; Schneider, D. & Steiger, J.
Object Type: Article
System: The UNT Digital Library
Highly charged ion trapping and cooling (open access)

Highly charged ion trapping and cooling

In the past few years a cryogenic Penning trap (RETRAP) has been operational at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory. The combination of RETRAP and EBIT provides a unique possibility of producing and re-trapping highly charged ions and cooling them to very low temperatures. Due to the high Coulomb potentials in such an ensemble of cold highly charged ions the Coulomb coupling parameter (the ratio of Coulomb potential to the thermal energy) can easily reach values of 172 and more. To study such systems is not only of interest in astrophysics to simulate White Dwarf star interiors but opens up new possibilities in a variety of areas (e.g. laser spectroscopy), cold highly charged ion beams.
Date: October 22, 1998
Creator: Beck, B. R.; Church, D. A.; Gruber, L.; Holder, J. P.; Schneider, D. & Steiger, J.
Object Type: Article
System: The UNT Digital Library
Health and safety considerations for U. S. monitors in the Russian transparency program. (open access)

Health and safety considerations for U. S. monitors in the Russian transparency program.

In 1993 the US and the Russian Federation signed an agreement allowing the US to purchase highly enriched uranium (HEU) from Russia over a 20-year period. This Highly Enriched Uranium Purchase Agreement permits the purchase of 500 metric tons of HEU from dismantled Russian nuclear weapons in the form of low-enriched uranium (LEU) for use as power reactor fuel in the US. Under the HEU Agreement, the US and Russia are cooperating in a ''Transparency Program'' to ensure that arms control and nonproliferation objectives are being met. The Transparency Program measures, which are a departure from traditional, intrusive measures of verification, include sending individuals from the US to Russia to monitor the processing of the HEU.
Date: October 22, 1998
Creator: Boggs, C. J.
Object Type: Article
System: The UNT Digital Library
Numerical Models of Broad-Bandwidth Nanosecond Optical Parametric Oscillators (open access)

Numerical Models of Broad-Bandwidth Nanosecond Optical Parametric Oscillators

We present three new methods for modeling broad-bandwidth, nanosecond optitcal parametric oscillators in the plane-wave approximation. Each accounts for the group-velocity differences that determine the operating linewidth of unseeded optical parametric oscillators, and each allows the signal and idler waves to develop from quantum noise. The first two methods are based on split-step integration methods in which nonlinear mixing and propagation are calculated separately on alternate steps. One method relies on Fourier transforming handle propagation, wiih mixing integrated over a the fields between t and u to Az step: the other transforms between z and k= in the propagation step, with mixing integrated over At. The third method is based on expansion of the three optical fields in terms of their respective longitudinal empty cavity modes, taking into account the cavity boundary condi- tions. Equations describing the time development of the mode amplitudes are solved to yield the time dependence of the three output fields. These plane-wave models exclude diffractive effects, but can be readily extended to include them.
Date: October 22, 1998
Creator: Bowers, M. S.; Gehr, Russell J. & Smith, A. V.
Object Type: Article
System: The UNT Digital Library
New Microscopic Model of the Staebler-Wronski Effect in Hydrogenated Amorphous Silicon (open access)

New Microscopic Model of the Staebler-Wronski Effect in Hydrogenated Amorphous Silicon

A new microscopic and kinetic model of light-induced metastability in hydrogenated amorphous silicon (a-Si:H) was recently proposed. Carrier recombination excites H from deep Si-H bonds into a mobile configuration, leaving a threefold-coordinated Si dangling bond (DB) defect at the site of excitation - a process long suspected to be an element of metastable DB production. Normally, mobile H are recaptured at DB defects and neither metastability nor net DB production results. However, when two mobile H collide, they form a metastable two-hydrogen complex and leave two spatially-uncorrelated Staebler-Wronski DBs. The model leads to differential equations describing the evolution of the mobile H and DB densities and a variety of new predictions. New directions for improving the stability of a-Si:H are discussed.
Date: October 22, 1998
Creator: Branz, H. M.
Object Type: Article
System: The UNT Digital Library
Fiscal year 1998 Battelle performance evaluation agreement revision 1 (open access)

Fiscal year 1998 Battelle performance evaluation agreement revision 1

Fiscal Year 1998 represents the second full year utilizing a results-oriented, performance-based contract. This document describes the critical outcomes, objectives, performance indicators, expected levels of performance, and the basis for the evaluation of the Contractors performance for the period October 1, 1997 through September 30, 1998, as required by Articles entitled Use of Objective Standards of Performance, Self Assessment and Performance Evaluation and Critical Outcomes Review of the Contract DE-AC08-76RLO1830. In partnership with the Contractor and other key customers, the Department of Energy (DOE) Richland Operations Office has defined six critical outcomes that same as the core for the Contractors performance evaluation. The Contractor also utilizes these outcomes as a basis for overall management of the Laboratory. As stated above six critical outcomes have been established for FY 1998. These outcomes are based on the following needs identified by DOE-HQ, RL and other customers of the Laboratory. Our Energy Research customer desires relevant, quality and cost effective science. Our Environmental Management customer wants technology developed, demonstrated, and deployed to solve environmental cleanup issues. To ensure the diversification and viability of the Laboratory as a National asset, RL and HQ alike want to increase the Science and Technical contributions of PNNL …
Date: October 22, 1998
Creator: Davis, T. L.
Object Type: Report
System: The UNT Digital Library
Fiscal year 1999 Battelle performance evaluation and fee agreement (open access)

Fiscal year 1999 Battelle performance evaluation and fee agreement

Fiscal Year 1999 represents the third fill year utilizing a results-oriented, performance-based evaluation for the Contractor's operations and management of the DOE Pacific Northwest National Laboratory (here after referred to as the Laboratory). However, this is the first year that the Contractor's fee is totally performance-based utilizing the same Critical Outcomes. This document describes the critical outcomes, objectives, performance indicators, expected levels of performance, and the basis for the evaluation of the Contractor's performance for the period October 1, 1998 through September 30, 1999, as required by Clauses entitled ''Use of Objective Standards of Performance, Self Assessment and Performance Evaluation'' and ''Performance Measures Review'' of the Contract DE-ACO6-76RL01830. Furthermore, it documents the distribution of the total available performance-based fee and the methodology set for determining the amount of fee earned by the Contractor as stipulated within the causes entitled ''Estimated Cost and Annual Fee,'' ''Total Available Fee'' and ''Allowable Costs and Fee.'' In partnership with the Contractor and other key customers, the Department of Energy (DOE) Headquarters (HQ) and Richland Operations Office (RL) has defined four critical outcomes that serve as the core for the Contractor's performance-based evaluation and fee determination. The Contractor also utilizes these outcomes as a basis …
Date: October 22, 1998
Creator: Davis, T. L.
Object Type: Report
System: The UNT Digital Library
A neutronic feasibility study for LEU conversion of the IR-8 research reactor. (open access)

A neutronic feasibility study for LEU conversion of the IR-8 research reactor.

Equilibrium fuel cycle comparisons for the IR-8 research reactor were made for HEU(90%), HEU(36%), and LEU (19.75%) fuel assembly (FA) designs using three dimensional multi-group diffusion theory models benchmarked to detailed Monte Carlo models of the reactor. Comparisons were made of changes in reactivity, cycle length, average {sup 235}U discharge burnup, thermal neutron flux, and control rod worths for the 90% and 36% enriched IRT-3M fuel assembly and the 19.75% enriched IRT-4M fuel assembly with the same fuel management strategy. The results of these comparisons showed that a uranium density of 3.5 g/cm{sup 3} in the fuel meat would be required in the LEU IRT-4M fuel assembly to match the cycle length of the HEU(90%) IRT-3M FA and an LEU density of 3.7 g/cm{sup 3} is needed to match the cycle length of the HEU(36%) IRT-3M FA.
Date: October 22, 1998
Creator: Deen, J. R.
Object Type: Article
System: The UNT Digital Library
Hydrogen production and carbon dioxide recovery from KRW oxygen-blown gasification. (open access)

Hydrogen production and carbon dioxide recovery from KRW oxygen-blown gasification.

An oxygen-blown KRW integrated gasification combined-cycle plant producing hydrogen, electricity, and supercritical-CO{sub 2}, was studied in a full-energy cycle analysis extending from the cord mine to the final destination of the gaseous product streams. A location in the mid-western US was chosen 160-km from Old Ben No.26 mine which ships 3,866 tonnes/day of Illinois No.6 coal by diesel locomotive. Three parallel gasifier trains, each capable of providing 42% of the plant's 413.5 MW nominal capacity use a combined total of 3,488 tonnes/day of 1/4 inch prepared coal. The plant produces a net 52 MW of power and 3.71 x 10{sup 6} nm{sup 3}/day of 99.999% purity hydrogen which is sent 100 km by pipeline at 34 bars. The plant also produces 3.18 x 10{sup 6} nm{sup 3}3/day of supercritical CO{sub 2} at 143 bars, which is sequestered in enhanced oil recovery operations 500 km away. A CO{sub 2} emission rate of 1 kgCO{sub 2}/kWh was assumed for power purchases outside the fence of the IGCC plant.
Date: October 22, 1998
Creator: Doctor, R. D.
Object Type: Article
System: The UNT Digital Library
Stress corrosion cracking of Ni-base and Ti alloys under controlled potential (open access)

Stress corrosion cracking of Ni-base and Ti alloys under controlled potential

Susceptibility to stress corrosion cracking (SCC) of alloy C-22 and Ti Gr-12, two candidate alloys for the inner-container of the multi-barrier nuclear waste package, was evaluated by using the slow-strain-rate (SSR) test technique in a deaerated acidic brine (pH {approx} 2.70) at 90 C. The strain rate used was 3.3 x 10{sup {minus}6} sec{sup {minus}1}. Prior to being tested in the acidic brine, specimens of each alloy were pulled inside the test chamber in the dry condition at room temperature (RT). Then specimens were exposed to the test solution while being strained under different controlled electrochemical potentials. The magnitude of the controlled potential was selected based on the corrosion potential measured in the test solution prior to straining of the specimen. Results indicate that, for Ti Gr-12, the times to failure were significantly shorter compared to those for alloy C-22. Furthermore, Ti Gr-12 showed reduced ductility in terms of percent reduction in area and true fracture stress, as the controlled potential became more cathodic. Results also indicate that the time-to-failure and percent elongation reached the minimum values when Ti Gr-12 was tested under impressed potential of {minus}1162 mV. Finally, metallographic examination was performed to evaluate the primary fracture, and the …
Date: October 22, 1998
Creator: Estill, J. C.; Gordon, S. R.; Logeteta, L. F. & Roy, A. K.
Object Type: Article
System: The UNT Digital Library
Statement of Work (SOW) for services provided by the Waste Sampling and Characterization Facility for the Effluent and Environmental Monitoring Program during calendar year 1998 (open access)

Statement of Work (SOW) for services provided by the Waste Sampling and Characterization Facility for the Effluent and Environmental Monitoring Program during calendar year 1998

This document defines the services the Waste Sampling and Characterization Facility (WSCF) shall provide the Effluent and Environmental Monitoring Program (EEM) throughout the calendar year for analysis. The purpose of the EEM Program is to monitor liquid and gaseous effluents, and the environment immediately around the facilities which may contain radioactive and hazardous materials. Monitoring data are collected, evaluated, and reported to determine their degree of compliance with applicable federal and state regulations and permits.
Date: October 22, 1998
Creator: Gleckler, B. P.
Object Type: Report
System: The UNT Digital Library
Multilevel Inverters for Electric Vehicle Applications (open access)

Multilevel Inverters for Electric Vehicle Applications

This paper presents multilevel inverters as an application for all-electric vehicle (EV) and hybrid-electric vehicle (HEV) motor drives. Diode-clamped inverters and cascaded H-bridge inverters, (1) can generate near-sinusoidal voltages with only fundamental frequency switching; (2) have almost no electromagnetic interference (EMI) and common-mode voltage; and (3) make an EV more accessible/safer and open wiring possible for most of an EV'S power system. This paper explores the benefits and discusses control schemes of the cascade inverter for use as an EV motor drive or a parallel HEV drive and the diode-clamped inverter as a series HEV motor drive. Analytical, simulated, and experimental results show the superiority of these multilevel inverters for this new niche.
Date: October 22, 1998
Creator: Habetler, Thomas G.; Peng, Fang Z. & Tolbert, Leon M.
Object Type: Article
System: The UNT Digital Library
Annual Hanford Seismic Report for Fiscal Year 1998 (open access)

Annual Hanford Seismic Report for Fiscal Year 1998

No abstract is available for this document at this time.
Date: October 22, 1998
Creator: Hartshorn, Donald C.; Reidel, Steve P. & Rohay, Alan C.
Object Type: Report
System: The UNT Digital Library
Soft commutated direct current motor [summary of proposed paper] (open access)

Soft commutated direct current motor [summary of proposed paper]

A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.
Date: October 22, 1998
Creator: Hsu, John S.
Object Type: Article
System: The UNT Digital Library
Search for Neutron to Anti-Neutron Transitions at HFIR/ORNL (open access)

Search for Neutron to Anti-Neutron Transitions at HFIR/ORNL

The transition of neutron to anti-neutron might be the first observed signal of the baryon instability long-awaited in Grand Unification models and required for the explanation of baryon asymmetry in the universe. A newly-proposed experiment to search for neutron-antineutron transitions at High Flux Isotope Reactor at Oak Ridge National Laboratory can improve the discovery potential by factor of {approximately} 1,000 relative to the existing limits. Further prospects of n -> n(overbar) search are also discussed in this paper.
Date: October 22, 1998
Creator: Kamyshkov, Y.
Object Type: Article
System: The UNT Digital Library
SUBSURFACE CONSTRUCTION AND DEVELOPMENT ANALYSIS (open access)

SUBSURFACE CONSTRUCTION AND DEVELOPMENT ANALYSIS

None
Date: October 22, 1998
Creator: Kramer, Norman E.
Object Type: Report
System: The UNT Digital Library
X-ray absorption near-edge spectroscopy of plutonium solid species. (open access)

X-ray absorption near-edge spectroscopy of plutonium solid species.

We present XANES at the L{sub III} edge for four plutonium solid phases: Pu(III)F{sub 3}, Pu(IV)O{sub 2}, NaPu(V)O{sub 2}CO{sub 3}, and Ba{sub 3}Pu(VI)O{sub 6}. These correspond to the four important oxidation states in the process chemistry and environmental chemistry of plutonium. By a fitting method that uses an arc tangent function and gaussian curves, it was possible to reproducibly determine the edge energy and distinguish among the four oxidation states. These data demonstrate a 1.85 {+-} 0.20 eV shift per oxidation state.
Date: October 22, 1998
Creator: Kropf, A. J.
Object Type: Article
System: The UNT Digital Library
An indirect sensing technique for diesel fuel quantity control. Technical progress report, July 1--September 30, 1998 (open access)

An indirect sensing technique for diesel fuel quantity control. Technical progress report, July 1--September 30, 1998

The project has focused on a retrofit product suitable for installation on existing mechanically-governed diesel engines. Included in this potential market are almost all diesel-powered passenger cars and light trucks manufactured prior to the introduction of the most recent clean diesel engines equipped with particulate traps and electronic controls. Also included are heavy-duty trucks, transit vehicles, school buses, and agricultural equipment. This system is intended to prevent existing diesel engines from overfueling to the point of visible particulate emissions (smoke), while allowing maximum smoke-limited torque under all operating conditions. The system employs a microcontroller and a specialized exhaust particulate emission sensor to continuously generate and update an adaptive throttle-limit map. This map specifies a maximum allowable throttle position as a function of engine speed and coolant temperature. For mechanically regulated fuel injection systems, the throttle position limit is mechanized via a linear position actuator attached to the fuel injection pump. For electronically regulated injection systems, this limit is mechanized by interception and modification of the electronic throttle input to the system.
Date: October 22, 1998
Creator: MacCarley, C. Arthur
Object Type: Report
System: The UNT Digital Library
Effects of Substrate and Na Concentration on Device Properties, Junction Formation, and Film Microstructure in CuInSe2PV Devices (open access)

Effects of Substrate and Na Concentration on Device Properties, Junction Formation, and Film Microstructure in CuInSe2PV Devices

Different concentrations of Na were systematically introduced into CuInSe2 (CIS) photovoltaic solar cell absorber material on different substrates (SLG, Si02/SLG, 7059, alumina) to: (1) determine the resultant effects on device properties, junction formation, and material microstructure; and (2) determine the optimal range of Na concentrations in the CIS films per specific substrate. In general, finished devices show improved Voc, Jsc, and device efficiency, improved charge-collection efficiency and, possibly, increased grain size as a result of the coevaporation of 4 to 100 mg of Na2Se during film deposition. However, a dramatic devolution set in with the addition of 235 mg of Na2Se, and all the aforementioned parameters were either at, or worse than, their pre-Na-addition levels. Meanwhile, although the device microstructure improves with Na addition and, more importantly, the junction (as characterized by electron-beam-induced current) has become much more uniform and closer to the heteroface, all that reverses with the ''Na overdose.''
Date: October 22, 1998
Creator: Matson, R. J.; Granata, J. E.; Asher, S. E. & Young, M. R.
Object Type: Article
System: The UNT Digital Library
US-RERTR Advanced Fuel Development Plans : 1999. (open access)

US-RERTR Advanced Fuel Development Plans : 1999.

Twelve fuel alloys were included in the very-high-density RERTR-1 and RERTR-2 microplate irradiation experiments. Experience gained during fabrication and results from the post-irradiation examination of these fuels has allowed us to narrow the focus of our fuel development efforts in preparation for the next set of irradiation experiments. Specific technical problems in both the areas of fuel fabrication and irradiation performance remain to be addressed. Examples of these are powder fabrication, fuel phase gamma stability versus density, and fuel-matrix interaction. In order to more efficiently address metal alloy fuel performance issues, work will continue on establishing a theoretical basis for alloy stability and metal alloy dispersion fuel irradiation performance. Plans to address these fuel development issues in the coming year will be presented.
Date: October 22, 1998
Creator: Meyer, M. K.
Object Type: Article
System: The UNT Digital Library
Particulate Contacts to Si and CdTe: Al, Ag, Hg-Cu-Te, and Sb-Te (open access)

Particulate Contacts to Si and CdTe: Al, Ag, Hg-Cu-Te, and Sb-Te

Our team has been investigating the use of particle-based contacts in both Si and CdTe solar cell technologies. First, in the area of contacts to Si, powders of Al and Ag prepared by an electroexplosion process have been characterized by transmission electron microscopy (TEM), TEM elemental determination X-ray spectroscopy (TEM-EDS), and TEM electron diffraction (TEM-ED). These Al and Ag particles were slurried and tested as contacts to p- and n-type silicon wafers, respectively. Linear current-voltage (I-V) was observed for Ag on n-type Si, indicative of an ohmic contact, whereas the Al on p-type Si sample was non-ideal. A wet-chemical surface treatment was performed on one Al sample and TEM-EDS indicated a substantial decrease in the O contaminant level. The treated Al on p-type Si films exhibited linear I-V after annealing. Second, in the area of contacts to CdTe, particles of Hg-Cu-Te and Sb-Te have been applied as contacts to CdTe/CdS/SnO2 heterostructures prepared by the standard NREL protocol. First, Hg-Cu-Te and Sb-Te were prepared by a metathesis reaction. After CdCl2 treatment and NP etch of the CdTe layer, particle contacts were applied. The Hg-Cu-Te contacted cells exhibited good electrical characteristics, with Voc > 810 mV and efficiencies > 11.5 % for …
Date: October 22, 1998
Creator: Schulz, D. L.; Ribelin, D.; Curtis, C. J. & Ginley, D. S.
Object Type: Article
System: The UNT Digital Library
Innovative regulatory approach for synthetic-based muds. (open access)

Innovative regulatory approach for synthetic-based muds.

The oil and gas industry has historically used water-based muds (WBMs) and oil-based muds (OBMs) in offshore drilling operations. WBMs are less expensive and are widely used. Both the WBMs and the associated drill cuttings maybe discharged from the platform to the sea provided that U.S. Environmental Protection Agency (EPA) discharge limitations are met. In some wells, however, difficult drilling conditions may force a switch from a WBM to an OBM. Neither the OBM nor the associated drill cuttings may be discharged. The OBM is hauled to shore, where it is processed for reuse, while the associated cuttings are injected in a disposal well at the platform or hauled to shore to a disposal facility. Both of these options are expensive. Synthetic-based muds (SBMs) are drilling fluids that use synthetic organic chemicals as base fluids. SBMs were developed to replace OBMs in difficult drilling situations. SBMs are more expensive than OBMs; however, they have superior environmental properties that may permit the cuttings to be discharged on-site. Like OBMs, SBMs are hauled ashore for processing and reuse after the well is drilled. The existing national effluent limitations guidelines (ELGs) for the offshore industry do not include requirements for SBM-cuttings since SBMs …
Date: October 22, 1998
Creator: Veil, J. A.
Object Type: Article
System: The UNT Digital Library
Management of offshore wastes in the United States. (open access)

Management of offshore wastes in the United States.

During the process of finding and producing oil and gas in the offshore environment operators generate a variety of liquid and solid wastes. Some of these wastes are directly related to exploration and production activities (e.g., drilling wastes, produced water, treatment workover, and completion fluids) while other types of wastes are associated with human occupation of the offshore platforms (e.g., sanitary and domestic wastes, trash). Still other types of wastes can be considered generic industrial wastes (e.g., scrap metal and wood, wastes paints and chemicals, sand blasting residues). Finally, the offshore platforms themselves can be considered waste materials when their useful life span has been reached. Generally, offshore wastes are managed in one of three ways--onsite discharge, injection, or transportation to shore. This paper describes the regulatory requirements imposed by the government and the approaches used by offshore operators to manage and dispose of wastes in the US.
Date: October 22, 1998
Creator: Veil, J. A.
Object Type: Article
System: The UNT Digital Library