States

A 100-kV, 2-kA, 2.5-{micro}S Pulser for Developing and Calibrating Long-Pulse Diagnostics (open access)

A 100-kV, 2-kA, 2.5-{micro}S Pulser for Developing and Calibrating Long-Pulse Diagnostics

The development of voltage and current probes for measuring an electron beam's current and position associated with several microsecond-long pulses from advanced Linear Induction Accelerators requires a precision pulser that can deliver both high voltages and high currents to a diagnostics Test Line. Seven-stage, type-E PFNs have been utilized in both a transformer and 4-stage Marx (plus/minus) configuration. The resulting 50-ohm pulser delivers to the Test Line a repeatable 100 kV, ca. 2 {micro}s flat-top ({+-} 1%), 2.5 {micro}s FWHM pulse with a rise time of 175 ns and 500 ns for the transformer and Marx options, respectively. Methods of reducing the rise time for both options are discussed and modeled. The coaxial Test Line is insulated at up to two atmospheres with SF{sub 6} and includes two transition regions to hold and test different diameter beam current and position monitors (BPMs). The center conductor incorporates both translation and tip/tilt with an accuracy of 100 {micro}m. Finally, the line is terminated in a matched radial resistor that provides a planar region at fields up to 40 kV/cm for the testing of voltage probes. Both the transformer and Marx options are modeled and compared to experimental results.
Date: June 27, 1999
Creator: Carlson, R.L.
Object Type: Article
System: The UNT Digital Library
The 40th AAAS Gordon Conference on nuclear chemistry (open access)

The 40th AAAS Gordon Conference on nuclear chemistry

I am pleased to speak at the Fortieth Gordon Conference on Nuclear Chemistry. I served as Chairman of the first Gordon Conference on Nuclear Chemistry held June 23--27, 1952, at New Hampton, New Hampshire. In my remarks, during which I shall quote from my journal, I shall describe some of the background leading up to the first Gordon Conference on Nuclear Chemistry and my attendance at the first seven Gordon Conferences during the period 1952 through 1958. I shall also quote my description of my appearance as the featured speaker at the Silver Anniversary of the Gordon Research Conferences on December 27, 1956 held at the Commodore Hotel in New York City. I shall begin with reference to my participation in the predecessor to the Gordon Conferences, the Gibson Island Research Conferences 45 years ago, on Thursday, June 20, 1946, as a speaker. This was 15 years after the start of these conferences in 1931. Neil Gordon played a leading role in these conferences, which were named (in 1948) in his honor -- the Gordon Research Conferences -- soon after they were moved to Colby Junior College, New London, New Hampshire in 1947. W. George Parks became Director in 1947, …
Date: June 27, 1991
Creator: Seaborg, G. T.
Object Type: Article
System: The UNT Digital Library
Air Quality: EPA's Proposed New Ozone and Particulate Matter Standards (open access)

Air Quality: EPA's Proposed New Ozone and Particulate Matter Standards

This report discusses the contentious issue of enforcing stringent national ambient air quality standards (NAAQS) for ozone and particulate matter (PM), the opponents of which decry as harmful to the economy. The report discusses actions undertaken by the EPA, President Clinton's support of the NAAQSs, and the criticisms of opponents.
Date: June 27, 1997
Creator: Blodgett, John E.; Parker, Larry & McCarthy, James E.
Object Type: Report
System: The UNT Digital Library
Atlas Transmission Line/Transition Design and Fabrication Status (open access)

Atlas Transmission Line/Transition Design and Fabrication Status

Atlas is a pulsed-power facility under development at Los Alamos National Laboratory to drive high-energy density experiments. Design has been completed for this new generation pulsed-power machine consisting of an azimuthal array of 24, 240-kV Marx modules and transmission lines supplying current to the load region at the machine center. The transmission line consists of a cable header, load protection switch, and tri-plate assembly interfacing to the center transition section. The cable header interface to the Marx module provides a mechanism to remove the Marx module for maintenance without removing other components of the transmission line. The load protection switch provides a mechanism for protecting the load during charging of the Marx in the event of a pre-fire condition. The aluminum tri-plate is a low-inductance transmission line carries radial current flow from the Marx energy storage system at the machine periphery toward the load. All transmission line components are oil insulated except the solid-dielectric insulated power flow channel connected directly to the load. The transition region at the machine center consists of several components that enable the radial converging vertical transmission lines to interface to a horizontal disk/conical power flow channel delivering current to the load. The current carrying transition …
Date: June 27, 1999
Creator: Ballard, E. O.; Baca, D. M.; Davis, H. A.; Elizondo, J. M.; Gribble, R. F.; Nielsen, K. E. et al.
Object Type: Article
System: The UNT Digital Library
ATP for the portable 500 CFM exhauster POR-005 skid C (open access)

ATP for the portable 500 CFM exhauster POR-005 skid C

This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-005 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.
Date: June 27, 1997
Creator: Keller, C. M.
Object Type: Report
System: The UNT Digital Library
Chemical identity of atoms using core electron annihilations (open access)

Chemical identity of atoms using core electron annihilations

Positron annihilation spectroscopy is a sensitive probe for studying the electronic structure of defects in solids. The high momentum part of the Doppler-broadened annihilation spectra can be used to distinguish different elements. This is achieved by using a new two-detector coincidence system and by imposing appropriate kinematic cuts to exclude background events. The new setup improves the peak to background ratio in the annihilation spectrum to {approximately}10{sup 5}. As a result, the line shape variations arising from different core electrons can be studied. The new approach adds elemental specificity to the Doppler broadening technique, and is useful in studying elemental variations around a defect site. Results from several case studies are reviewed.
Date: June 27, 1997
Creator: Asoka-Kumar, P.
Object Type: Article
System: The UNT Digital Library
Clutter sensitivity test under controlled field conditions Resonant Microstrip Patch Antenna (RMPA) sensor technology (open access)

Clutter sensitivity test under controlled field conditions Resonant Microstrip Patch Antenna (RMPA) sensor technology

Theoretical research, controlled laboratory tests, and these field test results show that nonmetallic (and metallic) shallowly buried objects can be detected and imaged with the Resonant Microstrip Patch Antenna (RMPA) sensor. The sensor can be modeled as a high Q cavity which capitalizes on its resonant condition sensitivity to scattered waves from buried objects. When the RMPA sensor is swept over a shallowly buried object, the RMPA fed-point impedance (resistance), measured with a Maxwell bridge, changes by tens of percent. The significant change in unprocessed impedance data can be presented in two-dimensional and three-dimensional graphical displays over the survey area. This forms silhouette images of the objects without the application of computationally intensive data processing algorithms. Because RMPA employed electromagnetic waves to illuminate the shallowly buried object, a number of questions and issues arise in the decision to fund or deny funding of the reconfiguration of the RMPA technology into a nonmetallic (metallic) land mine detector.
Date: June 27, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Code Differentiation for Hydrodynamic Model Optimization (open access)

Code Differentiation for Hydrodynamic Model Optimization

Use of a hydrodynamics code for experimental data fitting purposes (an optimization problem) requires information about how a computed result changes when the model parameters change. These so-called sensitivities provide the gradient that determines the search direction for modifying the parameters to find an optimal result. Here, the authors apply code-based automatic differentiation (AD) techniques applied in the forward and adjoint modes to two problems with 12 parameters to obtain these gradients and compare the computational efficiency and accuracy of the various methods. They fit the pressure trace from a one-dimensional flyer-plate experiment and examine the accuracy for a two-dimensional jet-formation problem. For the flyer-plate experiment, the adjoint mode requires similar or less computer time than the forward methods. Additional parameters will not change the adjoint mode run time appreciably, which is a distinct advantage for this method. Obtaining ''accurate'' sensitivities for the j et problem parameters remains problematic.
Date: June 27, 1999
Creator: Henninger, R.J. & Maudlin, P.J.
Object Type: Article
System: The UNT Digital Library
Composition of simulants used in the evaluation of electrochemical processes for the treatment of high-level wastes (open access)

Composition of simulants used in the evaluation of electrochemical processes for the treatment of high-level wastes

Four simulants are being used in the evaluation of electrochemical processes for the treatment of high-level wastes (HLW). These simulants represent waste presently stored at the Hanford, Idaho Falls, Oak Ridge, and Savannah River sites. Three of the simulants are highly alkaline salt solutions (Hanford, Oak Ridge, and Savannah River), and one is highly acidic (Idaho Falls).
Date: June 27, 1994
Creator: Hobbs, D. T.
Object Type: Report
System: The UNT Digital Library
Corrective Action Investigation Plan: Roller Coaster Lagoons and North Disposal Trench, Tonopah Test Range, Revision 1 (open access)

Corrective Action Investigation Plan: Roller Coaster Lagoons and North Disposal Trench, Tonopah Test Range, Revision 1

1.1 Purpose The purpose of this investigation is to collect data to confirm the presence or absence of contamination, evaluate the potential for contaminant migration, and select appropriate closure methods for these sites. The potential closure methods for these sites involve either clean closure, closure in place, or no further action. 1.2 Scope The scope of this investigation includes collecting surface and subsurface soil samples at the Roller Coaster Lagoons; and collecting surface soil samples at the North Disposal Trench and the small spill area associated with the Voluntary Cotiective Action (VCA) that was conducted in 1995.
Date: June 27, 1996
Creator: IT Corporation, Las Vegas, NV
Object Type: Report
System: The UNT Digital Library
Definition and means of maintaining the supply ventilation system seismic shutdown portion of the PFP safety envelope. Revision 2 (open access)

Definition and means of maintaining the supply ventilation system seismic shutdown portion of the PFP safety envelope. Revision 2

This report describes the modifications to the ventilation system for the Plutonium Finishing Plant. Topics discussed in this report include; system functional requirements, evaluations of equipment, a list of drawings showing the safety envelope boundaries; list of safety envelope equipment, functional requirements for individual safety envelope equipment, and a list of the operational, maintenance and surveillance procedures necessary to operate and maintain the system equipment.
Date: June 27, 1995
Creator: Keck, R. D.
Object Type: Report
System: The UNT Digital Library
Derivation of preliminary specifications for transmitted wavefront and surface roughness for large optics used in inertial confinement fusion (open access)

Derivation of preliminary specifications for transmitted wavefront and surface roughness for large optics used in inertial confinement fusion

In preparation for beginning the design of the Nation Ignition Facility (NIF) in the United States and the Laser Mega-Joule (LMJ) in France, the authors are in the process of deriving new specifications for the large optics required for these facilities. Traditionally, specifications for transmitted wavefront and surface roughness of large ICF optics have been based on parameters which were easily measured during the early 1980`s, such as peak-to-valley wavefront error (PV) and root-mean-square (RMS) surface roughness, as well as wavefront gradients in terms of waves per cm. While this was convenient from a fabrication perspective, since the specifications could be easily interpreted by fabricators in terms which were understood and conventionally measurable, it did not accurately reflect the requirements of the laser system. For the NIF and LMJ laser systems, the authors use advances in metrology and interferometry and an enhanced understanding of laser system performance to derive specifications which are based on power spectral densities (PSD`s.) Such requirements can more accurately reflect the requirements of the laser system for minimizing the amplitude of mid- and high-spatial frequency surface and transmitted wavefront errors, while not over constraining the fabrication in terms of low spatial frequencies, such as residual coma …
Date: June 27, 1995
Creator: Aikens, D.; Roussel, A. & Bray, M.
Object Type: Report
System: The UNT Digital Library
Direct conversion of plutonium-containing materials to borosilicate glass for storage or disposal (open access)

Direct conversion of plutonium-containing materials to borosilicate glass for storage or disposal

A new process, the Glass Material Oxidation and Dissolution System (GMODS), has been invented for the direct conversion of plutonium metal, scrap, and residue into borosilicate glass. The glass should be acceptable for either the long-term storage or disposition of plutonium. Conversion of plutonium from complex chemical mixtures and variable geometries into homogeneous glass (1) simplifies safeguards and security; (2) creates a stable chemical form that meets health, safety, and environmental concerns; (3) provides an easy storage form; (4) may lower storage costs; and (5) allows for future disposition options. In the GMODS process, mixtures of metals, ceramics, organics, and amorphous solids containing plutonium are fed directly into a glass melter where they are directly converted to glass. Conventional glass melters can accept materials only in oxide form; thus, it is its ability to accept materials in multiple chemical forms that makes GMODS a unique glass making process. Initial proof-of-principle experiments have converted cerium (plutonium surrogate), uranium, stainless steel, aluminum, and other materials to glass. Significant technical uncertainties remain because of the early nature of process development.
Date: June 27, 1995
Creator: Forsberg, C. W. & Beahm, E. C.
Object Type: Article
System: The UNT Digital Library
Discontinuous Galerkin for Stiff Hyperbolic Systems (open access)

Discontinuous Galerkin for Stiff Hyperbolic Systems

A Discontinuous Galerkin (DG) method is applied to hyperbolic systems that contain stiff relaxation terms. We demonstrate that when the relaxation time is under-resolved, DG is accurate in the sense that the method accurately represents the system's Chapman-Enskog (or ''diffusion'') approximation. Moreover, we demonstrate that a high-resolution, finite-volume method using the same time-integration method as DG is very inaccurate in the diffusion limit. Results for DG are presented for the hyperbolic heat equation, the Broadwell model of gas kinetics, and coupled radiation-hydrodynamics.
Date: June 27, 1999
Creator: Lowrie, Robert B. & Morel, Jim E.
Object Type: Article
System: The UNT Digital Library
Disposition of Nuclear Waste Using Subcritical Accelerator-Driven Systems (open access)

Disposition of Nuclear Waste Using Subcritical Accelerator-Driven Systems

ATW destroys virtually all the plutonium and higher actinides without reprocessing the spent fuel in a way that could lead to weapons material diversion. An ATW facility consists of three major elements: (1) a high-power proton linear accelerator; (2) a pyrochemical spent fuel treatment i waste cleanup system; (3) a liquid lead-bismuth cooled burner that produces and utilizes an intense source-driven neutron flux for transmutation in a heterogeneous (solid fuel) core. The concept is the result of many years of development at LANL as well as other major international research centers. Once demonstrated and developed, ATW could be an essential part of a global non-proliferation strategy for countries that could build up large quantities of plutonium from their commercial reactor waste. ATW technology, initially proposed in the US, has received wide and rapidly increasing attention abroad, especially in Europe and the Far East with major programs now being planned, organized and tided. Substantial convergence presently exists on the technology choices among the programs, opening the possibility of a strong and effective international collaboration on the phased development of the ATW technology.
Date: June 27, 1998
Creator: Doolen, G. D.; Venneri, F.; Li, N.; Williamson, M. A.; Houts, M. & Lawrence, G.
Object Type: Article
System: The UNT Digital Library
EGDM foam shell status report (TAT 95-049) (open access)

EGDM foam shell status report (TAT 95-049)

We have completed an investigation of a low density foam made from ethylene glycol dimethacrylate (EGDM). We are confident that we have attained foam properties similar to those reported by Osaka, such as foam density ({approximately}60 mg/cc) and visibility of optical interference fringes. However, the material undergoes significant shrinkage during supercritical CO{sub 2} drying which hinders additional target fabrication steps. We also discuss issues related to preparing shells using a droplet generator and overcoating this material with hydroxyethyl cellulose.
Date: June 27, 1995
Creator: Lambert, S.; Overturf, G.; Cook, B. & Schroen-Carey, D.
Object Type: Report
System: The UNT Digital Library
Engineering development of advanced physical fine coal cleaning for premium fuel applications. Task 6 -- Selective agglomeration laboratory research and engineering development for premium fuels (open access)

Engineering development of advanced physical fine coal cleaning for premium fuel applications. Task 6 -- Selective agglomeration laboratory research and engineering development for premium fuels

The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and benchscale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report represents the findings of Subtask 6.5 Selective Agglomeration Bench-Scale Testing and Process Scale-up. During this work, six project coals, namely Winifrede, Elkhorn No. 3, Sunnyside, Taggart, Indiana VII, and Hiawatha were processed in a 25 lb/hr continuous selective agglomeration bench-scale test unit.
Date: June 27, 1997
Creator: Moro, N. & Jha, M. C.
Object Type: Report
System: The UNT Digital Library
Enhanced Electron Attachment to Highly-Excited Molecules and Its Applications in Pulsed Plasmas (open access)

Enhanced Electron Attachment to Highly-Excited Molecules and Its Applications in Pulsed Plasmas

Studies conducted over the past several years have shown that electron attachment to highly-excited states of molecules have extremely large cross sections. We will discuss the implications of this for pulsed discharges used for H<sup>-</sup> generation, material processing, and plasma remediation.
Date: June 27, 1999
Creator: Ding, W. X.; Ma, C. Y.; McCorkle, D. L. & Pinnaduwage, L. A.
Object Type: Article
System: The UNT Digital Library
[Establish and manage a National Resource Center for plutonium, Quarterly report, April 1, 1995--June 30, 1995] (open access)

[Establish and manage a National Resource Center for plutonium, Quarterly report, April 1, 1995--June 30, 1995]

The initial phase of the Plutonium Information Resource is well under way. Board members developed linkages with Russian scientists and engineers and obtained names of technical team members. Nuclear proposals were reviewed by the Nuclear Review Group, and the proposals were modified to incorporate the review group`s comments. Portions of the proposals were approved by the Governing Board. Proposals for education and outreach were reviewed by the Education Proposal Review Group, considered by the Governing Board and approved. The Senior Technical Review Group met to consider the R&D programs associated with fissile materials disposal. A newsletter was published. Progress continued on the high explosives demonstration project, on site-specific environmental work, and the multiattribute utility analysis. Center offices in Amarillo were furnished, equipment was purchased, and the lease was modified.
Date: June 27, 1995
Creator: Mulder, R.
Object Type: Report
System: The UNT Digital Library
Evaluation of materials and surface treatments for the DWPF melter pour spout bellows protective liner (open access)

Evaluation of materials and surface treatments for the DWPF melter pour spout bellows protective liner

A study was undertaken to evaluate a variety of materials and coatings for the DWPF pour spout bellows liner. The intent was to identify materials that would minimize or eliminate adherence of glass on the bellows liner wall and help minimize possible pluggage during glass pouring operations in DWPF. Glass has been observed adhering to the current bellow`s liner, which is made of 304L stainless steel. Materials were identified which successfully allowed molten glass to hit these surfaces and not adhere. Results of this study suggest that if these materials are used in the pouring system glass could still fall into the canister without appreciable plugging, even if an unstable glass stream is produced. The materials should next be evaluated under the most realistic DWPF conditions possible. Other findings of this study include the following: (1) increasing coupon thickness produced a favorable increase in the glass sticking temperature; (2) highly polished surfaces, with the exception of the oxygen-free copper coupon coated with Armoloy dense chromium, did not produce a significant improvement in the glass sticking temperature, increasing angle of contact of the coupon to the falling glass did not yield a significant performance improvement; (3) electroplating with gold and silver …
Date: June 27, 1997
Creator: Imrich, K. J.; Bickford, D. F. & Wicks, G. G.
Object Type: Report
System: The UNT Digital Library
Evaluation of melter technologies for vitrification of Hanford site low-level tank waste - phase 1 testing summary report (open access)

Evaluation of melter technologies for vitrification of Hanford site low-level tank waste - phase 1 testing summary report

Following negotiation of the fourth amendment to the Tri- Party Agreement for Hanford Site cleanup, commercially available melter technologies were tested during 1994 and 1995 for vitrification of the low-level waste (LLW) stream to be derived from retrieval and pretreatment of the radioactive defense wastes stored in 177 underground tanks. Seven vendors were selected for Phase 1 testing to demonstrate vitrification of a high-sodium content liquid LLW simulant. The tested melter technologies included four Joule-heated melters, a carbon electrode melter, a combustion melter, and a plasma melter. Various dry and slurry melter feed preparation processes also were tested. The technologies and Phase 1 testing results were evaluated and a preliminary technology down-selection completed. This report describes the Phase 1 LLW melter vendor testing and the tested technologies, and summarizes the testing results and the preliminary technology recommendations.
Date: June 27, 1996
Creator: Wilson, C. N.
Object Type: Report
System: The UNT Digital Library
Field Quality Improvements in Superconducting Magnets for RHIC (open access)

Field Quality Improvements in Superconducting Magnets for RHIC

A number of techniques have been developed and tested to improve the field quality in the superconducting dipole and quadrupole magnets to be used in the Relativistic Heavy Ion Collider (RHIC). These include adjustment in the coil midplane gap to compensate for the allowed and non-allowed harmonics, inclusion of holes and cutouts in the iron yoke to reduce the saturation-induced harmonics, and magnetic tuning shims to correct for the residual errors. We compare the measurements with the calculations to test the validity of these concepts.
Date: June 27, 1994
Creator: Gupta, R.; Jain, A.; Kahn, S.; Morgan, G.; Thompson, P.; Wanderer, P. et al.
Object Type: Article
System: The UNT Digital Library
Gas-driven microturbine (open access)

Gas-driven microturbine

This paper describes an invention which relates to microtechnology and the fabrication process for developing microelectrical systems. It describes a means for fabricating a gas-driven microturbine capable of providing autonomous propulsion in which the rapidly moving gases are directed through a micromachined turbine to power devices by direct linkage or turbo-electric generators components in a domain ranging from tenths of micrometers to thousands of micrometers.
Date: June 27, 1996
Creator: Sniegowski, J. J.; Rodgers, M. S.; McWhorter, P. J.; Aeschliman, D. P. & Miller, W. M.
Object Type: Patent
System: The UNT Digital Library
Geothermal Energy Program: Multiyear Plan, FY 1992-1997 (open access)

Geothermal Energy Program: Multiyear Plan, FY 1992-1997

None
Date: June 27, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library