This paper reports the development of 350 MHz superconducting cavities of a spoke-loaded geometry, intended for the velocity range 0.2 < v/c < 0.6. Two prototype single-cell cavities have been designed, one optimized for velocity v/c = 0.4, and the other for v/c = 0.29. Construction of the prototype niobium cavities is nearly complete. Details of the design and construction are discussed, along with the results of cold tests.

Ukraine operates thirteen (13) Soviet-designed pressurized water reactors, VVERS. All Ukrainian plants are currently operating with annually renewable permits until they update their safety analysis reports (SARs), in accordance with new SAR content requirements issued in September 1995, by the Nuclear Regulatory Authority and the Government Nuclear Power Coordinating Committee of Ukraine. The requirements are in three major areas: design basis accident (DBA) analysis, probabilistic risk assessment (PRA), and beyond design-basis accident (BDBA) analysis. The last two requirements, on PRA and BDBA, are new, and the DBA requirements are an expanded version of the older SAR requirements. The US Department of Energy (USDOE), as part of its Soviet-Designed Reactor Safety activities, is providing assistance and technology transfer to Ukraine to support their nuclear power plants (NPPs) in developing a Western-type technical basis for the new SARs. USDOE sponsored In-Depth Safety Assessments (ISAs) are in progress at three pilot nuclear reactor units in Ukraine, South Ukraine Unit 1, Zaporizhzhya Unit 5, and Rivne Unit 1, and a follow-on study has been initiated at Khmenytskyy Unit 1. The ISA projects encompass most areas of plant safety evaluation, but the initial emphasis is on performing a detailed, plant-specific Level 1 Internal Events PRA. …

Two Forward Time Projection Chambers (FTPC) provide charge and momentum information in the pseudorapidity range between 2.5 < |{eta}| < 4.0. A radial TPC scheme is used, where ionization electrons drift in an electric field perpendicular to the axial solenoidal magnetic field. Curved proportional wire chambers with pad readout record the track information via 19200 electronic channels. We report on measurements with various gas mixtures in a prototype chamber with and without magnetic field. The design and construction of a curved readout chamber is described. Based on the prototype measurements and the final layout of the detector the expected performance in measuring accuracy and two-track-separation is given.

Measurements by the E802 Collaboration of the A-dependence and pseudorapidity interval ({delta}{eta}) dependence of mid-rapidity ET distributions in a half-azimuth electromagnetic calorimeter are presented for p+Be, p+Au, O+Cu, Si+Au and Au+Au collisions at the BNL-AGS. The issues addressed are (1) whether the shapes of the upper edges of the ET distributions vary with {delta}{eta} similarly to the variation in shapes of mid-rapidity charged particle distributions and (2) how small a {delta}{eta} interval would still give a meaningful characterization of the ''nuclear geometry'' of a reaction. A new way of plotting ET distributions was found from which the reaction dynamics could be read directly.

Lawrence Livermore, Sandia Livermore and Los Alamos National Laboratories have a joint project to develop an optimized hydrogen fueled engine for series hybrid automobiles. The major divisions of responsibility are: system analysis, engine design and kinetics modeling by LLNL; performance and emission testing, and friction reduction by SNL; computational fluid mechanics and combustion modeling by LANL. This project is a component of the Department of Energy, Office of Utility Technology, National Hydrogen Program. We report here on the progress on system analysis and preliminary engine testing. We have done system studies of series hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. The impact of various on-board storage options on fuel economy are evaluated. Experiments with an available engine at the Sandia Combustion Research Facility demonstrated NO{sub x} emissions of 10 to 20 ppm at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid vehicle simulation studies indicate that exhaust NO{sub x} concentrations must be less than 180 ppm to meet the …

Electrochemical capacitative behavior of carbon aerogels and commercial carbon fiber cloths was studied in 5M KOH, 3M sulfuric acid, and 0.5M tetrethylammonium tetrafluoroborate/propylene carbonate electrolytes. The resorcinol-formaldehyde based carbon aerogels with a range of denisty (0.2-0.85 g/cc) have open-cell structures with ultrafine pore sizes (5-50 nm), high surface area (400-700 m{sup 2}/g), and a solid matrix composed of interconnected particles or fibers with characteristic diameters of 10 nm. The commercial fiber cloths in the density range 0.2-04g/cc have high surface areas (1000-2500 m{sup 2}/g). The volumetric capacitances of high-density aerogels are shown to be comparable to or exceeding those from activated carbon fibers. Electrochemical behavior of these materials in various electrolytes is compared and related to their physical properties.

An international team was assembled for the purpose of selecting suitable immobilization forms and processing technologies for the Fissile Materials Deposition Program Office. As a reference point, the team used the NAS study but did not limit their recommendations to those of the NAS. As a result, two basic forms were selected and the processing alternatives to provide those two forms were defined. Environmental data have been supplied to support a preliminary environmental impact statement for the disposition program. The immobilization program has also entered the R&D Phase and progress has been made on the formulation of both glass and ceramic forms. Samples of both glass and ceramics containing tens of grams of plutonium have been prepared which indicate that the required concentration range can be obtained. Long-term leach tests to verify performance requirements in the repository are also under way.

This paper examined effects of heat treatment and milling (before or after heat treatment) on the (electrochemical) intercalating ability of needle petroleum coke; natural graphite particles are included for comparison. 1 tab, 4 figs, 7 refs.

This report discusses activity at Los Alamos on the nuclear optical model. In particular, the following topics are discussed: format of the optical model parameter library; contents of the library; validation of the optical model library; and conclusions and recommendations.

As a part of its ongoing research efforts, Sandia National Laboratories` Transportation Surety Center investigates the integrity of various containment methods for hazardous materials transport, subject to anomalous structural and thermal events such as free-fall impacts, collisions, and fires in both open and confined areas. Since it is not possible to conduct field experiments for every set of possible conditions under which an actual transportation accident might occur, accurate modeling methods must be developed which will yield reliable simulations of the effects of accident events under various scenarios. This requires computer software which is capable of assimilating and processing data from experiments performed as benchmarks, as well as data obtained from numerical models that simulate the experiment. Software tools which can present all of these results in a meaningful and useful way to the analyst are a critical aspect of this process. The purpose of this work is to provide software resources on a long term basis, and to ensure that the data visualization capabilities of the Center keep pace with advancing technology. This will provide leverage for its modeling and analysis abilities in a rapidly evolving hardware/software environment.

The US government agreed to provide the Russian Federation with containers to support the dismantlement of Russian nuclear weapons as part of the Nunn-Lugar Cooperative Threat Reduction program. In February 1996, the ``affirmation`` of the Russian Fissile Material container design was completed. The ``affirmation`` process allowed a joint program between the Russian and US governments to proceed without the exchange of sensitive weapons specific information. The Russian Fissile Material container program is an integral part of the Cooperative Threat Reduction program wherein the US government provides assistance to the states of the Former Soviet Union for dismantlement of their nuclear stockpile. The Cooperative Threat Reduction program is managed by the US Defense Special Weapons Agency. Sandia National Laboratories was selected as the design agency and technical point of contact for the Russian Federation. The Department of Energy, which certifies containers for weapons shipments in the US, provided an independent assessment of the Sandia designed container to assure that it met the requirements of the August 31, 1993 AT-4OOR Container Requirements [Sandia National Laboratories, 1993] document which was agreed to by representatives of the US and Russian Federation. The ``affirmation`` process was undertaken in lieu of a certification process. This process …

Drain and overflow holes are integral to the nuclear criticality safety basis of many processes and provide different functions inachieving their safety goaL Inmost cases at the Oak RidgeY-12 Plant, unverified engineering judgment has been previously used to conclude that the holes were adequate to accomplish their mission. Such judgment may adequately serve some configurations but is inadequate in other applications. It is important to understand and document the exact function of every drain for both normal and upset process conditions. After this is accomplished, the holes must be demonstrated to be capable of penlorming their intended safety fi,mction. This paper gives examples of different types of drains used for criticality safety, gives examples of how to ensure they will work as intended, and gives guidance to the analyst who relies on such holes to prevent criticality accidents.

The authors review how a classification into representations of color and flavor can be used to understand the possible patterns of symmetry breaking for color superconductivity in dense quark matter. In particular, the authors show how for three flavors, color-flavor locking is precisely analogous to the usual pattern of chiral symmetry breaking in the QCD vacuum.

The worldwide market share for crystalline-silicon solar cells has increased steadily in the last 10 years. In 1998, about 87% of the photovoltaic modules shipped worldwide are based on crystalline silicon. This dominance will likely continue into at least the first few years of the 21st century. The long-term growth of crystalline-silicon solar cells will depend on the development of low-cost polysilicon feedstock, silicon films, and advanced cell and module manufacturing processes.

A major problem with cavitation in pumps and other hydraulic devices is that there is no effective method for detecting or predicting its inception. The traditional approach is to declare the pump in cavitation when the total head pressure drops by some arbitrary value (typically 3o/0) in response to a reduction in pump inlet pressure. However, the pump is already cavitating at this point. A method is needed in which cavitation events are captured as they occur and characterized by their process dynamics. The object of this research was to identify specific features of cavitation that could be used as a model-based descriptor in a context-dependent condition-based maintenance (CD-CBM) anticipatory prognostic and health assessment model. This descriptor was based on the physics of the phenomena, capturing the salient features of the process dynamics. An important element of this concept is the development and formulation of the extended process feature vector @) or model vector. Thk model-based descriptor encodes the specific information that describes the phenomena and its dynamics and is formulated as a data structure consisting of several elements. The first is a descriptive model abstracting the phenomena. The second is the parameter list associated with the functional model. The …

Erbium hydride thin films are grown onto polished, a-axis {alpha} Al{sub 2}O{sub 3} (sapphire) substrates by reactive ion beam sputtering and analyzed to determine composition, phase and microstructure. Erbium is sputtered while maintaining a H{sub 2} partial pressure of 1.4 x 10{sup {minus}4} Torr. Growth is conducted at several substrate temperatures between 30 and 500 C. Rutherford backscattering spectrometry (RBS) and elastic recoil detection analyses after deposition show that the H/Er areal density ratio is approximately 3:1 for growth temperatures of 30, 150 and 275 C, while for growth above {approximately}430 C, the ratio of hydrogen to metal is closer to 2:1. However, x-ray diffraction shows that all films have a cubic metal sublattice structure corresponding to that of ErH{sub 2}. RBS and Auger electron that sputtered erbium hydride thin films are relatively free of impurities.

The relative stability of LHC type cables has been measured by the direct heating of one of the individual strands with a short duration current pulse. The minimum energy required to initiate a quench has been determined for a number of cables which have a central core to increase the effective inter-strand cross-over resistance. Experiments were performed in both normal helium at 4.4 K and superfluid at 1.9 K. Conductors in general are less stable at the lower temperature when measured at the same fraction of critical current. Results show that the cored-cables, even when partially filled with solder or with a porous-metal filler exhibit a relatively low stability at currents close to the critical current. It is speculated that the high inter-strand electrical and thermal resistance inherent in these cables may effect the stability at high currents.

Processes that involve particle-laden fluids are common in geomechanics and especially in the petroleum industry. Understanding the physics of these processes and the ability to predict their behavior requires the development of coupled fluid-flow and particle-motion computational methods. This paper outlines an accurate and robust coupled computational scheme using the lattice-Boltzmann method for fluid flow and the discrete-element method for solid particle motion. Results from several two-dimensional validation simulations are presented. Simulations reported include the sedimentation of an ellipse, a disc and two interacting discs in a closed column of fluid. The recently discovered phenomenon of drafting, kissing, and tumbling is fully reproduced in the two-disc simulation.

In the scanning electron microscope (SEM), using electron backscattered diffraction (EBSD), it is possible to measure the spacing of the layers in the reciprocal lattice. These values are of great use in confirming the identification of phases. The technique derives the layer spacing from the HOLZ rings which appear in patterns from many materials. The method adapts results from convergent-beam electron diffraction (CBED) in the transmission electron microscope (TEM). For many materials the measured layer spacing compares well with the calculated layer spacing. A noted exception is for higher atomic number materials. In these cases an extrapolation procedure is described that requires layer spacing measurements at a range of accelerating voltages. This procedure is shown to improves the accuracy of the technique significantly. The application of layer spacing measurements in EBSD is shown to be of use for the analysis of two polytypes of SiC.

This paper describes a method for machine or process system diagnostics that uses one-step prediction maps. The method uses nonlinear time series analysis techniques to form a one-step prediction map that estimates the next time series data point when given a sequence of previously measured time series data point. The difference between the predicted and measured time series values is a measure of the map error. The average value of this error should remain within some bound as long as both the dynamic system and its operating condition remain unchanged. However, changes in the dynamic system or operating condition will cause an increase in average map error. Thus, for a constant operating condition, monitoring the average map error over time should indicate when a change has occurred in the dynamic system. Furthermore, the map error itself forms a time series that can be analyzed to detect changes in system dynamics. The paper provides technical background in the nonlinear analysis techniques used in the diagnostic method, describes the creation of one-step prediction maps and their application to machine or process system diagnostics, and then presents results obtained from applying the diagnostic method to simulated and measured data.

In the past few years charged kaon experiments have indicated possible scalar and tensor couplings in semileptonic kaon decays (K{yields}{pi}e{nu}). These couplings, if correct, are not predicted by the Standard Model and may indicate the onset of new physics. We present a summary of the existing data and a new, precision measurement of these couplings in the neutral kaon system based on a 3% subset of the data taken by the KTeV (E799) experiment at Fermilab.

Tracking studies of the Muon Collider 50 on 50 GeV col-lider ring [1] show that the on-momentum dynamic aper-ture is limited to around 10{sigma} even with the chromaticity sextupoles turned off. Numerical results from the normal form algorithm show that the tune-shift with amplitude is surprisingly large. Both analytical and numerical results are presented to show that nonlinear kinematic effect originated from the large angles of particles in the interaction region is responsible for the large tune-shift which in turn limits the dynamic aperture. Acomparative study of the LHC collider ring is also presented to demonstrate the difference between the two machines.

Our vision of the future of information systems is one that includes engineered collectives of software agents which are situated in an environment over years and which increasingly improve the performance of the overall system of which they are a part. At a minimum, the movement of agent and multi-agent technology into National Security applications, including their use in information assurance, is apparent today. The use of deliberative, autonomous agents in high-consequence/high-security applications will require a commensurate level of protection and confidence in the predictability of system-level behavior. At Sandia National Laboratories, we have defined and are addressing a research agenda that integrates the surety (safety, security, and reliability) into agent-based systems at a deep level. Surety is addressed at multiple levels: The integrity of individual agents must be protected by addressing potential failure modes and vulnerabilities to malevolent threats. Providing for the surety of the collective requires attention to communications surety issues and mechanisms for identifying and working with trusted collaborators. At the highest level, using agent-based collectives within a large-scale distributed system requires the development of principled design methods to deliver the desired emergent performance or surety characteristics. This position paper will outline the research directions underway at …

Weak link behavior is studied, using magnetization and Hall probe measurements of ring samples, in welded melt-textured R123 monoliths and in dual-seeded samples with disoriented domains. Techniques for welding samples yield transport currents across the junction that are in excess of 10{sup 4} A/cm{sup 2}.