We have examined the mechanical response of unalloyed Ta and Ta-W alloy annealed plates over a wide range of loadings. It was observed in general that Ta exhibits nonuniform mechanical behavior, for example, hourglassing of compression samples and multiple instabilities during tensile deformation. In contrast, the Ta-W alloys do not exhibit any unusual nonuniform behavior. This work presents data revealing the spatial distribution of texture in Ta and Ta-W alloys. Significant variations in texture both through the thickness and from one area of the plate to another were found to be characteristic of Ta. The dominant feature of the texture variations was found to be enhanced <111> crystal direction fractions at the center of the plate, with a decreasing fraction near the surface. We find that the variation in texture in the Ta-W alloys is substantially less than that seen in Ta with primarily a <100> cube texture throughout. This study suggest that the texture gradients are responsible for the nonuniform mechanical response of Ta and that the uniform behavior of the Ta-W alloys is a consequence of the absence of texture gradients.

This Cooperative Research and Development Agreement (CRADA) was a mutual research and development (R and D) effort among the participants to investigate a range of advanced manufacturing technologies for two silicon nitride (Si{sub 3}N{sub 4}) ceramic materials. The general objective was to identify the most cost-effective part manufacturing processes for the ceramic materials of interest. The focus was determining the relationship between material removal rates, surface quality, and the structural characteristics of each ceramic resulting from three innovative processes. These innovated machining processes were studied using silicon nitride advanced materials. The particular (Si{sub 3}N{sub 4}) materials of interest were sintered GS-44 from the Norton Company, and reaction-bonded Ceraloy 147-3. The processes studied included the following activities: (1) direct laser machining; (2) rotary ultrasonic machining; and (3) diamond abrasive grinding, including both resinoid and vitreous-bonded grinding wheels. Both friable and non-friable diamond types were included within the abrasive grinding study. The task also conducted a comprehensive survey of European experience in use of ceramic materials, principally aluminum oxide. Originally, the effort of this task was to extend through a prototype manufacturing demonstration of selected engine components. During the execution of this program, however changes were made to the scope of the …

The overall objective of the Project is the expedited commercialization of advanced coal-fired low-emission boiler systems. The Project is under budget and generally on schedule. The current status is shown in the Milestone Schedule Status Report included as Appendix A. Under Task 7--Component development and optimization, the CeraMem filter testing was completed. Due to an unacceptably high flue gas draft loss, which will not be resolved in the POCTF timeframe, a decision was made to change the design of the flue gas cleaning system from Hot SNO{sub x}{sup {trademark}} to an advanced dry scrubber called New Integrated Desulfurization (NID). However, it is recognized that the CeraMem filter still has the potential to be viable in pulverized coal systems. In Task 8-- Preliminary POCTF design, integrating and optimizing the performance and design of the boiler, turbine/generator and heat exchangers of the Kalina cycle as well as the balance of plant design were completed. Licensing activities continued. A NID system was substituted for the SNO{sub x} Hot Process.

A critical step in the fabrication of integrated circuits is the deposition of metal layers which interconnect the various circuit elements that have been formed in earlier process steps. In particular, columns of copper several times higher than the characteristic dimension of the circuit elements was needed. Features with a diameter of a few tenths of a micron and a height of about one micron need to be filled at rates in the half to one micron per minute range. With the successful development of a copper deposition technology meeting these requirements, integrated circuits with simpler designs and higher performance could be economically manufactured. Several technologies for depositing copper were under development. No single approach had an optimum combination of performance (feature characteristics), cost (deposition rates), and manufacturability (integration with other processes and tool reliability). Chemical vapor deposition, plating, sputtering and ionized-physical vapor deposition (I-PVD) were all candidate technologies. Within this project, the focus was on I-PVD.

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A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic and metallurgical performance of the circuit, variables such as reagent dosage, air addition rate, pulp density and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in video-based sensor technology are being applied for on-line determination of slurry ash content. During the third quarter of this project, work continued on the testing and calibration of the video-based ash analyzer, and a plant sampling campaign was conducted to provide data for the development of a mathematical process model and the model-based control algorithms.

This report from the Amarillo National Resource Center for Plutonium describes progress in the following areas: electronic resource library; the senior technical review group; environment, health, and safety and remedial action activities; communications, education, and training; and plutonium and other materials.

Ion implantation of O into Al and growth of Al(O) layers using electro-cyclotron resonance plasma and pulsed laser depositions produce composite alloys with a high density of nanometer-size oxide precipitates in an Al matrix. The precipitates impart high strength to the alloy and reduced adhesion during sliding contact, while electrical conductivity and ductility are retained. Implantation of N into Al produces similar microstructures and mechanical properties. The athermal energies of deposited atoms are a key factor in achieving these properties.

This note describes my analysis of the measurement of the electron energy distribution function in a DC glow discharge reported by T. Kimura, K. Akatsuka, and K. Ohe, in `Experimental and theoretical investigations of DC glow discharges in argon-nitrogen mixtures,`J. Phys. D: Appl. Phys. 27 (1994) 1664-1671. T. Kimura of the Department of Systems Engineering at the Nagoya Institute of Technology sent me this paper in 1994, as well as `Electron Energy Distribution Function in Neon-Nitrogen Mixture Positive Column,` T. Kimura, and K. Ohe, Jpn. J. Appl. Phys. Vol. 3 1, Part 1, No. 12A, December 1992, pp. 4051- 4052. I base my analysis on the data for a pure N{sub 2} discharge at p=1 torr in the 1994 paper. Figures 2 and 3 in that paper show a discrepancy between f({epsilon}) as measured by Langmuir probing and f({epsilon}) as calculated from E/N based on the measured axial field. Kimura et. al. explain their observation of hotter than expected electrons on superelastic collisions with vibrationally excited nitrogen. My fundamental point is that the radial field generated by ambipolar diffusion significantly augments E/N above the contribution from the axial field in this experiment, and creates a higher than expected radially averaged …

The objectives of this project were to develop computationally efficient numerical methods for modeling surfactant flooding in enhanced oil recovery and aquifer remediation. Surfactants have been considered by several oil companies to reduce the large residual oil saturations, and are being seriously considered for cleanup of dense contaminants in aquifers, particularly chlorinated hydrocarbons. The authors employed second-order Godunov methods for the discretization of the conservation laws, and lowest-order mixed finite element methods for the discretization of the pressure equation. They also used dynamically adaptive mesh refinement to concentrate the computational work. The development of the second-order Godunov method required a mathematical analysis of the hyperbolic wave structure; this analysis discovered undesirable features f the model that lead to infinite characteristic speeds. Minor modifications of the model to remove the infinite characteristic speeds improved the stability of the model considerably. The use of adaptive mesh refinement required the development of several techniques for upscaling various physical quantities, and a multigrid iteration for the pressure equation on an adaptively refined grid. Numerical simulations showed that the second-order Godunov method is reasonably effective in preserving sharp fluid fronts, but is too computationally expensive in so complex a fluid model. On the other hand, …

Mass spectrometers and residual gas analyzers (RGA) are used in a variety of applications for analysis of volatile and semi-volatile materials. Analysis is performed by detecting fragments of gas molecules, based on their mass to charge ratio, which are generated in the mass spectrometer. When used as a detector for a gas chromatograph, they function as a means to quantitatively identify isolated volatile species which have been separated from other species via the gas chromatograph. Vacuum Technology, Inc., (VTI) produces a magnetic sector mass spectrometer/RGA which is used in many industrial and laboratory environments. In order to increase the utility of this instrument, it is desirable to increase the mass scanning speed, thereby increasing the number of applications for which it is suited. This project performed the following three upgrades on the computer interface. (1) A new electrometer was designed and built to process the signal from the detector. This new electrometer is more sensitive, over 10 times faster, and over 100 times more stable than the electrometer it will replace. (2) The controller EPROM was reprogrammed with new firmware. This firmware acts as an operating system for the interface and is used to shuttle communications between the PC and …

This document provides information regarding the source and the estimated quantity of potential airborne radionuclide emissions resulting from the operation of the Cold Vacuum Drying (CVD) Facility. The construction of the CVD Facility is scheduled to commence on or about December 1996, and will be completed when the process begins operation. This document serves as a Notice of Construction (NOC) pursuant to the requirements of 40 Code of Federal Regulations (CFR) 61 for the CVD Facility. About 80 percent of the U.S. Department of Energy`s spent nuclear fuel (SNF) inventory is stored under water in the Hanford Site K Basins. Spent nuclear fuel in the K West Basin is contained in closed canisters, while the SNF in the K East Basin is in open canisters, which allow release of corrosion products to the K East Basin water. Storage of the current inventory in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PURF-X Plant left approximately 2,100 MT (2,300 tons) of uranium as part of the N Reactor SNF in the K …

A method for fabricating composite pressure vessels having toroidal geometry was evaluated. Eight units were fabricated using fibrous graphite material wrapped over a thin-walled aluminum liner. The material was wrapped using a machine designed for wrapping, the graphite material was impregnated with an epoxy resin that was subsequently thermally cured. The units were fabricated using various winding patterns. They were hydrostatically tested to determine their performance. The method of fabrication was demonstrated. However, the improvement in performance to weight ratio over that obtainable by an all metal vessel probably does not justify the extra cost of fabrication.

Methods for limiting the size of hadronic spin-flip in the Coulomb- Nuclear Interference. region are critically assessed. This work was presented at the High Energy Polarimetry Workshop in Amsterdam, Sept. 9, 1996 and the RHIC Spin Collaboration meeting in Marseille, Sept. 17, 1996.

The Department of Energy (DOE) has expressed a need for an on-line, real-time instrument for assaying alpha-emitting radionuclides (uranium and the transuranics) in effluent waters leaving DOE sites to ensure compliance with regulatory limits. Due to the short range of alpha particles in water ({approximately}40 Tm), it is necessary now to intermittently collect samples of water and send them to a central laboratory for analysis. A lengthy and costly procedure is used to separate and measure the radionuclides from each sample. Large variations in radionuclide concentrations in the water may go undetected due to the sporadic sampling. Even when detected, the reading may not be representative of the actual stream concentration. To address these issues, Tecogen, a division of Thermo Power Corporation, a Thermo Electron company, is developing a real-time, field-deployable, alpha monitor based on a solid-state silicon wafer semiconductor (patent pending, to be assigned to the Department of Energy). The Thermo Alpha Monitor (TAM) will serve to monitor effluent water streams (Subsurface Contaminants Focus Area) and will be suitable for process control of remediation as well as decontamination and decommissioning operations, such as monitoring scrubber or rinse water radioactivity levels (Mixed Waste Focus Area and D&amp;D Focus Area). It …

We explore the capability of a 500 or 1000 GeV e{sup +} e{sup {minus}} linear collider to measure anomalous quartic gauge boson couplings. In the framework of a non-linear effective Lagrangian with a custodial SU(2) symmetry, there are only two next-to-leading order operators which contribute to quartic, but not to two- and three-gauge boson interactions. The limits on the coefficients of these operators from present and future e{sup +} e{sup {minus}} colliders are compared with those available from other sources.

The major groups engaged in transmutation research are converging towards a common objective and similar technology. It is now possible to envision an international program of research aimed at the destruction of reactor-generated (and other) nuclear waste using a series of multipurpose experimental facilities in the near future. Los Alamos National Laboratory, as the home of the highest power LINAC and a very active transmutation technology project, is the ideal host for the first of such facilities. The next step in the international program (a facility 10 times more powerful, for engineering-scale demonstrations) could be built in Europe, where there is substantial interest in the construction of such a device in the framework of international cooperation. A series of experiments at Las Alamos could explore the key transmutation technologies. Liquid lead loops, a liquid lead spallation target, and a large size liquid lead facility with provision for irradiation, cooling and diagnostics of several types of `transmutation assemblies`, where different transmutation concepts will be tested in different media and environments, from transmutation of fission products to destruction by fission of higher actinides, to other waste management applications. The engineering-scale facility, which will follow the initial testing phase, will extend the best …

We present a general phenomenological analysis of a class of Two Higgs Doublet Models with Flavor Changing Neutral Currents arising at the tree level. The existing constraints mainly affect the couplings of the first two generations of quarks, leaving the possibility for non negligible Flavor Changing couplings of the top quark open. The next generation of lepton and hadron colliders will offer the right environment to study the physics of the top quark and to unravel the presence of new physics beyond the Standard Model. In this context we discuss some interesting signals from Flavor Changing Scalar Neutral Currents.

Supersymmetry (SUSY) is an appealing concept which provides a plausible solution to the fine tuning problem, while leaving the phenomenological success of the Standard Model (SM) unchanged. Moreover, some SUSY models allow for the unification of gauge couplings at a scale of M{sub GUT} {approx} 10{sup 16} GeV. A further attractive feature is the possibility of radiative breaking of the electro-weak symmetry group SU(2) {times} U(1). The masses of the SUSY partners of the SM particles are expected to be in the range 100 GeV to 1 TeV. One of the main goals of the Large Hadron Collider (LHC) will be either to discover weak-scale SUSY or to exclude it over the entire theoretically allowed parameter space. The authors have developed a strategy for the analysis of experimental data at LHC which will allow them to determine the scale for supersymmetry, to limit the model parameter space, and to make precision measurements of model parameters.

We have made the first measurement of defects in an aged sample of {delta} phase, Ga stabilized Pu, using positron annihilation lifetime spectroscopy. This measurement validates the procedure necessary to perform measurements on this highly toxic material and obtain data representative of sample conditions. Comparison of the positron annihilation lifetime analysis of the data with calculated values suggests that He filled vacancies or vacancy clusters dominate the defect population. Such defects are the necessary precursor to void growth and swelling. The evolution of defects resulting from the radioactive decay of Pu during its life in the stockpile is one of the unknown quantities affecting our confidence in predictions of the limit on stockpile components. Radiation damage leads to changes in the size and strength of metals studied for reactor and accelerator use and similar effects may be expected in Pu. The evolution of radiation produced vacancies into larger void structures and accompanying macroscopic swelling may occur in Pu at some age. A detailed understanding of the defects in self irradiated Pu is required to predict the time scale of void swelling and related radiation effects. 1 fig.

This report contains the proceedings of the Imaging Sciences Workshop sponsored by C.A.S.LS., the Center for Advanced Signal & Image Sciences. The Center, established primarily to provide a forum where researchers can freely exchange ideas on the signal and image sciences in a comfortable intellectual environment, has grown over the last two years with the opening of a Reference Library (located in Building 272). The Technical Program for the 1996 Workshop include a variety of efforts in the Imaging Sciences including applications in the Microwave Imaging, highlighted by the Micro-Impulse Radar (MIR) system invented at LLNL, as well as other applications in this area. Special sessions organized by various individuals in Speech, Acoustic Ocean Imaging, Radar Ocean Imaging, Ultrasonic Imaging, and Optical Imaging discuss various applica- tions of real world problems. For the more theoretical, sessions on Imaging Algorithms and Computed Tomography were organized as well as for the more pragmatic featuring a session on Imaging Systems.

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DOE`s FY 1996 budget of $18 billion included $1.1 billion for construction projects; ensuring that these projects meet bonafide existing or future DOE needs becomes increasingly important as DOE`s missions evolve and its organization changes. In 1994 and 1995, IG issued several reports expressing concerns about the construction planning process and questioned whether planned construction was necessary to meet mission needs. The reports also pointed out that DOE did not ensure that originally identified needs were still valid several years after a project`s conception. (The problems identified were at single locations.) While DOE management did not agree with all aspects of the audit reports, it canceled or downsized several projects and initiated a number of process improvements to enhance the construction planning process. Purpose of this report is to synthesize issues from these prior reports to assist management in focusing process improvement efforts to avoid construction of unneeded or oversized facilities.

The Transportable Vitrification System (TVS) is a large-scale, fully-integrated, transportable, vitrification system for the treatment of low-level nuclear and mixed wastes in the form of sludges, soils, incinerator ash, and similar waste streams. The TVS was built to demonstrate the vitrification of actual mixed waste at U. S. Department of Energy (DOE) sites. Currently, Westinghouse Savannah River Company (WSRC) is working with Lockheed Martin Energy Systems (LMES) to apply field scale vitrification to actual mixed waste at Oak Ridge Reservation`s (ORR) K-25 Site. Prior to the application of the TVS to actual mixed waste it was tested on simulated K-25 B and C Pond waste at Clemson University. This paper describes the results of that testing and preparations for the demonstration on actual mixed waste.