Publications

On March 20, 1998, Sandia National Laboratories performed a double-blind test of the DKL LifeGuard human presence detector and tracker. The test was designed to allow the device to search for individuals well within the product`s published operational parameters. The Test Operator of the DKL LifeGuard was provided by the manufacturer and was a high-ranking member of DKL management. The test was developed and implemented to verify the performance of the device as specified by the manufacturer. The device failed to meet its published specifications and it performed no better than random chance.

Despite the best preventative measures, ruptured hoses, spills and leaks occur with use of all hydraulic equipment. Although these releases do not usually produce a RCRA regulated waste, they are often a reportable occurrence. Clean-up and subsequent administrative procedure involves additional costs, labor and work delays. Concerns over these releases, especially related to Sandia National Laboratories (SNL) vehicles hauling waste on public roads prompted Fleet Services (FS) to seek an alternative to the standard petroleum based hydraulic fluid. Since 1996 SNL has participated in a pilot program with the University of Iowa (UNI) and selected vehicle manufacturers, notably John Deere, to field test hydraulic fluid produced from soybean oil in twenty of its vehicles. The vehicles included loaders, graders, sweepers, forklifts and garbage trucks. Research was conducted for several years at UNI to modify and market soybean oils for industrial uses. Soybean oil ranks first in worldwide production of vegetable oils (29%), and represents a tremendous renewable resource. Initial tests with soybean oil showed excellent lubrication and wear protection properties. Lack of oxidative stability and polymerization of the oil were concerns. These concerns were being addressed through genetic alteration, chemical modification and use of various additives, and the improved lubricant is in the field testing stage.

The aim of this laboratory-directed research and development project was to study amorphous carbon (a-C) thin films for eventual cold-cathode electron emitter applications. The development of robust, cold-cathode emitters are likely to have significant implications for modern technology and possibly launch a new industry: vacuum micro-electronics (VME). The potential impact of VME on Sandia`s National Security missions, such as defense against military threats and economic challenges, is profound. VME enables new microsensors and intrinsically radiation-hard electronics compatible with MOSFET and IMEM technologies. Furthermore, VME is expected to result in a breakthrough technology for the development of high-visibility, low-power flat-panel displays. This work covers four important research areas. First, the authors studied the nature of the C-C bonding structures within these a-C thin films. Second, they determined the changes in the film structures resulting from thermal annealing to simulate the effects of device processing on a-C properties. Third, they performed detailed electrical transport measurements as a function of annealing temperature to correlate changes in transport properties with structural changes and to propose a model for transport in these a-C materials with implications on the nature of electron emission. Finally, they used scanning atom probes to determine important aspects on the nature of emission in a-C.

Net erosion rates of carbon target plates have been measured in situ for the DIII-D lower divertor. The principal method of obtaining this data is the DiMES sample probe. Recent experiments have focused on erosion at the outer strike-point of two divertor plasma conditions: (1) attached (Te > 40 eV) ELMing plasmas and (2) detached (Te < 2 eV) ELMing plasmas. The erosion rates for the attached cases are > 10 cm/year, even with incident heat flux < 1 MW/m{sup 2}. In this case, measurements and modeling agree for both gross and net carbon erosion, showing the near-surface transport and redeposition of the carbon is well understood and that effective sputtering yields are > 10%. In ELM-free discharges, this erosion rate can account for the rate of carbon accumulation in the core plasma. Divertor plasma detachment eliminates physical sputtering, while spectroscopically measured chemical erosion yields are also found to be low (Y(C/D{sup +}) {le} 2.0 {times} 10{sup {minus}3}). This leads to suppression of net erosion at the outer strike-point, which becomes a region of net redeposition ({approximately} 4 cm/year). The private flux wall is measured to be a region of net redeposition with dense, high neutral pressure, attached divertor plasmas. Leading edges intercepting parallel heat flux ({approximately} 50 MW/m{sup 2}) have very high net erosion rates ({approximately} 10 {micro}m/s) at the OSP of an attached plasma. Leading edge erosion, and subsequent carbon redeposition, caused by tile gaps can account for half of the deuterium codeposition in the DIII-D divertor.

This paper describes the design and design issues associated with silicon surface micromachined device design Some of the tools described are adaptations of macro analysis tools. Design issues in the microdomain differ greatly from design issues encountered in the macrodomain. Microdomain forces caused by electrostatic attraction, surface tension, Van der Walls forces, and others can be more significant than inertia, friction, or gravity. Design and analysis tools developed for macrodomain devices are inadequate in most cases for microdomain devices. Microdomain specific design and analysis tools are being developed, but are still immature and lack adequate functionality. The fundamental design process for surface micromachined devices is significantly different than the design process employed in the design of macro-sized devices. In this paper, MEMS design will be discussed as well as the tools used to develop the designs and the issues relating fabrication processes to design. Design and analysis of MEMS devices is directly coupled to the silicon micromachining processes used to fabricate the devices. These processes introduce significant design limitations and must be well understood before designs can be successfully developed. In addition, some silicon micromachining fabrication processes facilitate the integration of silicon micromachines with microelectronics on-chip. For devices requiring on-chip electronics, the fabrication processes introduce additional design constraints that must be taken into account during design and analysis.

Many manufacturing companies today expend more effort on upgrade and disposal projects than on clean-slate design, and this trend is expected to become more prevalent in coming years. However, commercial CAD tools are better suited to initial product design than to the product`s full life cycle. Computer-aided analysis, optimization, and visualization of life cycle assembly processes based on the product CAD data can help ensure accuracy and reduce effort expended in planning these processes for existing products, as well as provide design-for-lifecycle analysis for new designs. To be effective, computer aided assembly planning systems must allow users to express the plan selection criteria that apply to their companies and products as well as to the life cycles of their products. Designing products for easy assembly and disassembly during its entire life cycle for purposes including service, field repair, upgrade, and disposal is a process that involves many disciplines. In addition, finding the best solution often involves considering the design as a whole and by considering its intended life cycle. Different goals and constraints (compared to initial assembly) require one to re-visit the significant fundamental assumptions and methods that underlie current assembly planning techniques. Previous work in this area has been limited to either academic studies of issues in assembly planning or applied studies of life cycle assembly processes, which give no attention to automatic planning. It is believed that merging these two areas will result in a much greater ability to design for; optimize, and analyze life cycle assembly processes.

An agile microsystem manufacturing technology has been developed that provides unprecedented 5 levels of independent polysilicon surface-micromachine films for the designer. Typical surface-micromachining processes offer a maximum of 3 levels, making this the most complex surface-micromachining process technology developed to date. Leveraged from the extensive infrastructure present in the microelectronics industry, the manufacturing method of polysilicon surface-micromachining offers similar advantages of high-volume, high-reliability, and batch-fabrication to microelectromechanical systems (MEMS) as has been accomplished with integrated circuits (ICs). These systems, comprised of microscopic-sized mechanical elements, are laying the foundation for a rapidly expanding, multi-billion dollar industry 2 which impacts the automotive, consumer product, and medical industries to name only a few.

Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single boron-epoxy composite doubler to the damaged structure. In order for the use of composite doublers to achieve widespread use in the civil aviation industry, it is imperative that methods be developed which can quickly and reliably assess the integrity of the doubler. In this study, a specific composite application was chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Primary among inspection requirements for these doublers is the identification of disbonds, between the composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the doubler is also a concern. No single nondestructive inspection (NDI) method can inspect for every flaw type, therefore it is important to be aware of available NDI techniques and to properly address their capabilities and limitations. A series of NDI tests were conducted on laboratory test structures and on full-scale aircraft fuselage sections. Specific challenges, unique to bonded composite doubler applications, were highlighted. An array of conventional and advanced NDI techniques were evaluated. Flaw detection sensitivity studies were conducted on applicable eddy current, ultrasonic, X-ray and thermography based devices. The application of these NDI techniques to composite doublers and the results from test specimens, which were loaded to provide a changing flaw profile, are presented in this report. It was found that a team of these techniques can identify flaws in composite doubler installations well before they reach critical size.

This report describes ship accident event trees, ship collision and ship fire frequencies, representative ships and shipping practices, a model of ship penetration depths during ship collisions, a ship fire spread model, cask to environment release fractions during ship collisions and fires, and illustrative consequence calculations. This report contains the following appendices: Appendix 1 -- Representative Ships and Shipping Practices; Appendix 2 -- Input Data for Minorsky Calculations; Appendix 3 -- Port Ship Speed Distribution; and Appendix 4 -- Cask-to-Environment Release Fractions.

The engineering of advanced semiconductor heterostructure materials and devices requires a detailed understanding of, and control over, the structure and properties of semiconductor materials and devices at the atomic to nanometer scale. Cross-sectional scanning tunneling microscopy has emerged as a unique and powerful method to characterize structural morphology and electronic properties in semiconductor epitaxial layers and device structures at these length scales. The basic experimental techniques in cross-sectional scanning tunneling microscopy are described, and some representative applications to semiconductor heterostructure characterization drawn from recent investigations in the authors laboratory are discussed. Specifically, they describe some recent studies of InP/InAsP and InAsP/InAsSb heterostructures in which nanoscale compositional clustering has been observed and analyzed.

On July 1--2, 1997, Sandia National Laboratories hosted the External Committee to Evaluate Sandia`s Risk Expertise. Under the auspices of SIISRS (Sandia`s International Institute for Systematic Risk Studies), Sandia assembled a blue-ribbon panel of experts in the field of risk management to assess their risk programs labs-wide. Panelists were chosen not only for their own expertise, but also for their ability to add balance to the panel as a whole. Presentations were made to the committee on the risk activities at Sandia. In addition, a tour of Sandia`s research and development programs in support of the US Nuclear Regulatory Commission was arranged. The panel attended a poster session featuring eight presentations and demonstrations for selected projects. Overviews and viewgraphs from the presentations are included in Volume 1 of this report. Presentations are related to weapons, nuclear power plants, transportation systems, architectural surety, environmental programs, and information systems.

An exploratory study was conducted under the Architectural Surety Program to examine the possibility of modifying fracture of glass in the shock-wave environment associated with terrorist bombings. The intent was to explore strategies to reduce the number and severity of injuries resulting from those attacks. The study consisted of a series of three experiments at the Energetic Materials Research and Testing Center (EMRTC) of the New Mexico Institute of Mining and Technology at Socorro, NM, in which annealed and tempered glass sheets were exposed to blast waves at several different levels of overpressure and specific impulse. A preliminary assessment of the response of tempered glass to the blast environment suggested that inducing early failure would result in lowering fragment velocity as well as reducing the loading from the window to the structure. To test that possibility, two different and novel procedures (indentation flaws and spot annealing) were used to reduce the failure strength of the tempered glass while maintaining its ability to fracture into small cube-shaped fragments. Each experiment involved a comparison of the performance of four sheets of glass with different treatments.

SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. Previously, the SPH algorithm has been subjected to detailed testing and analysis to determine the feasibility of using the coupled finite-element/SPH code PRONTO/SPH for the analysis of various types of underwater explosion problems involving fluid-structure and shock-structure interactions. Here, SPH and Eulerian simulations are used to study the details of underwater bubble collapse, particularly the formation of re-entrant jets during collapse, and the loads generated on nearby structures by the jet and the complete collapse of the bubble. Jet formation is shown to be due simply to the asymmetry caused by nearby structures which disrupt the symmetry of the collapse. However, the load generated by the jet is a minor precursor to the major loads which occur at the time of complete collapse of the bubble.

This paper discusses thermal analysis in support of probabilistic risk assessment (PRA) to predict the heating of cargoes shipped in vehicles like the Safe Secure Trailer. Fire environments contribute very significantly to the risk associated with ground transport of special nuclear materials. The tradeoff between thermal model complexity and the affordable number of scenarios used to represent the hazard space is discussed as it impacts PRA. The relevant heat transfer mechanisms are discussed along with the applicability of methods from the literature for analysis of these mechanisms. Many of the subject`s real problems remain too complex for affordable and rigorous analysis. Available models are generally restricted to idealizations that are quickly obviated by real effects. Approximate treatment methods, striving to produce conservative, realistic estimates are also discussed.

The suitability of modified thermal-battery technology for use as a potential power source for geothermal borehole applications is under investigation. As a first step, the discharge processes that take place in LiSi/LiBr-KBr-LiF/FeS{sub 2} thermal cells were studied at temperatures of 350 C and 400 C using pelletized cells with immobilized electrolyte. Incorporation of a reference electrode allowed the relative contribution of each electrode to the overall cell polarization to be determined. The results of single-cell tests are presented, along with preliminary data for cells based on a lower-melting CsBr-LiBr-KBr eutectic salt.

An array of chemically-sensitive field-effect transistors (CHEMFETs) that measure both work function and bulk resistance changes in thin films was used to detect volatile organic compounds. Carbon black/organic polymer composite films were deposited onto the CHEMFETs using an automated microdispensing method.

The Waste Isolation Pilot Plant (WIPP) is a planned geologic repository for permanent disposal of transuranic waste generated by US government defense programs. Located near Carlsbad in southeastern New Mexico, the facility`s disposal regions are mined from the bedded salt of the Salado Formation at a depth of approximately 652 m. Four shafts service the operational needs of the facility for air intake, exhaust, waste handling and salt handling. These shafts range in diameter from 3.5 to 6.1 m and extend from the ground surface to the repository. During repository closure, following an operational life of approximately 50 years, these shafts will be sealed in accordance with an acceptable design. Under contract to the US Department of Energy (DOE), the Repository Isolation Systems Department (RISD) of Sandia National Laboratories has developed a design for the WIPP shaft sealing system. This design has been reviewed by the US Environmental Protection Agency (EPA) as part of the 1996 WIPP Compliance Certification Application (CCA). An effective shaft sealing system for the WIPP will limit liquid and gas flows, and permanently prevent the migration of radiological or other hazardous constituents through the sealed shafts from repository to accessible environment. Because of these performance objectives, a significant effort has been directed toward evaluation of the seal design. Whereas RISD (1996) provides a comprehensive discussion, this paper focuses on only one aspect of the evaluation effort, namely a full shaft, fluid flow model.

The `public outcomes` from research universities are educated students and research that extends the frontiers of knowledge. Measures of these `public outcomes` are inadequate to permit either research or education consumers to select research universities based on quantitative performance data. Research universities annually spend over $20 billion on research; 60% of these funds are provided by Federal sources. Federal funding for university research has recently grown at an annual rate near 6% during a time period when other performers of Federal research have experienced real funding cuts. Ten universities receive about 25% of the Federal funds spent on university research. Numerous studies of US research universities are reporting storm clouds. Concerns include balancing research and teaching, the narrow focus of engineering education, college costs, continuing education, and public funding of foreign student education. The absence of research on the `public outcomes` from university research results in opinion, politics, and mythology forming the basis of too many decisions. Therefore, the authors recommend studies of other nations` research universities, studies of various economic models of university research, analysis of the peer review process and how well it identifies the most capable research practitioners and at what cost, and studies of research university ownership of intellectual property that can lead to increased `public outcomes` from publicly-funded research performed by research universities. They advocate two practices that could increase the `public outcomes` from university research. These are the development of science roadmaps that link science research to `public outcomes` and `public outcome` metrics. Changes in the university research culture and expanded use of the Internet could also lead to increased `public outcomes`. They recommend the use of tax incentives to encourage companies to develop research partnerships with research universities.

Vapor diffusion in porous media in the presence of its own liquid may be enhanced due to pore-scale processes, such as condensation and evaporation across isolated liquid islands. Webb and Ho (1997) developed a mechanistic pore-scale model of these processes under steady-state conditions in which condensation and evaporation on the liquid island were equal. The vapor diffusion rate was significantly enhanced by these liquid island processes by up to an order of magnitude compared to a dry porous media. However, vapor transport by diffusion is often complicated by transient effects, such as in drying applications, in which net evaporation of liquid may further augment the vapor flux from diffusion. The influence of transient effects on the enhancement factors for vapor diffusion is evaluated in this paper. In addition, the effect of vapor pressure lowering on the enhancement factor and on porescale vapor fluxes is shown.

The magnetically controlled plasma opening switch (MCPOS) is an advanced plasma opening switch that utilizes magnetic fields to improve operation. Magnetic fields always dominate terawatt, pulsed power plasma opening switches. For that reason, the MCPOS uses controlled applied magnetic fields with magnitude comparable to the self-magnetic field of the storage inductor. One applied field holds the plasma in place while energy accumulates in the storage inductor, then another applied field pushes the plasma away from the cathode to allow energy to flow downstream. Over a ten month period, an MCPOS was designed, built, and tested on DECADE Module 2 at Physics International. The peak drive current was 1.8 MA in 250 ns. The output parameters were up to 1 MA into an electron beam load. The radiation temporal pulse width averaged 60 nanoseconds full-width at half-maximum. The peak load voltage ranged from one to two megavolts. The experiments demonstrated efficient power flow through a long, low-impedance magnetically insulated transmission line between the magnetically controlled plasma opening switch and the load.

Economic and other factors accompanying developments in physics, mathematics and particularly in computer technology are shifting a substantial portion of the experimental resources associated with large scale engineering projects from physical testing to modeling and simulation. In the process, the priorities of selecting meaningful and informative tests and simulations to perform are also changing. This paper describes issues related to experimental design and how the goals and priorities of the experimental design for these problems are changing to accommodate the this shift in experimentation. Issues, priorities and new methods of approach are discussed.

The exposure of ATG graphite sample to DIII-D divertor plasma was provided by the DiMES (Divertor Material Evaluation System) mechanism. The graphite sample arranged to receive the parallel heat flux on a small region of the surface was exposed to 600ms of outer strike point plasma. The sample was constructed to collect the eroded material directed downward into a trapping zone onto s Si disk collector. The average heat flux onto the graphite sample during the exposure was about 200W/cm{sup 2}, and the parallel heat flux was about 10 KW/cm{sup 2}. After the exposure the graphite sample and Si collector disk were analyzed using SEM, NRA, RBS, Auger spectroscopy. IR and Raman spectroscopy. The thermal desorption was studied also. The deposited coating on graphite sample is amorphous carbon layer. Just upstream of the high heat flux zone the redeposition layer has a globular structure. The deposition layer on Si disk is composed also from carbon but has a diamond-like structure. The areal density of C and D in the deposited layer on Si disk varied in poloidal and toroidal directions. The maximum D/C areal density ratio is about 0.23, maximum carbon density is about 3.8 {times} 10{sup 18}cm{sup {minus}2}, maximum D area density is about 3 {times} 10{sup 17}cm{sup 2}. The thermal desorption spectrum had a peak at 1,250K.

Recent observations have indicated that lithium pellet injection wall conditioning plays an important role in achieving the enhanced supershot regime in TFTR. However, little is understood about the behavior of lithium-coated limiter walls, interacting with edge plasmas. In the final campaign of TFTR, a cylindrical carbon fiber composite probe was inserted into the boundary plasma region and exposed to ohmically-heated deuterium discharges with lithium pellet injection. The ion-drift side probe surface exhibits a sign of codeposition of lithium, carbon, oxygen, and deuterium, whereas the electron side essentially indicates high-temperature erosion. It is found that lithium is incorporated in these codeposits in the form of oxide at the concentration of a few percent. In the electron side, lithium has been found to penetrate deeply into the probe material, presumably via rapid diffusion through interplane spaces in the graphite crystalline. Though it is not conclusive, materials mixing in the carbon and lithium system appears to be a key process in successful lithium wall conditioning.

The advanced networking department at Sandia National Laboratories has used the annual Supercomputing conference sponsored by the IEEE and ACM for the past several years as a forum to demonstrate and focus communication and networking developments. At SC `97, Sandia National Laboratories (SNL), Los Alamos National Laboratory (LANL), and Lawrence Livermore National Laboratory (LLNL) combined their SC `97 activities within a single research booth under the Advance Strategic Computing Initiative (ASCI) banner. For the second year in a row, Sandia provided the network design and coordinated the networking activities within the booth. At SC `97, Sandia elected to demonstrate the capability of the Computation Plant, the visualization of scientific data, scalable ATM encryption, and ATM video and telephony capabilities. At SC `97, LLNL demonstrated an application, called RIPTIDE, that also required significant networking resources. The RIPTIDE application had computational visualization and steering capabilities. This paper documents those accomplishments, discusses the details of their implementation, and describes how these demonstrations support Sandia`s overall strategies in ATM networking.

The SAMPLL (Simplified Analytical Model of Penetration with Lateral Loading) computer code was originally developed in 1984 to realistically yet economically predict penetrator/target interactions. Since the code`s inception, its use has spread throughout the conventional and nuclear penetrating weapons community. During the penetrator/target interaction, the resistance of the material being penetrated imparts both lateral and axial loads on the penetrator. These loads cause changes to the penetrator`s motion (kinematics). SAMPLL uses empirically based algorithms, formulated from an extensive experimental data base, to replicate the loads the penetrator experiences during penetration. The lateral loads resulting from angle of attack and trajectory angle of the penetrator are explicitly treated in SAMPLL. The loads are summed and the kinematics calculated at each time step. SAMPLL has been continually improved, and the current version, Version 6.0, can handle cratering and spall effects, multiple target layers, penetrator damage/failure, and complex penetrator shapes. Version 6 uses the latest empirical penetration equations, and also automatically adjusts the penetrability index for certain target layers to account for layer thickness and confinement. This report describes the SAMPLL code, including assumptions and limitations, and includes a user`s guide.

Sandia National Laboratories designed the H1616 container for transport of Type B quantities of radioactive materials. During the most recent recertification cycle, questions were raised concerning the ability of drum type containers with locking rings to survive the hypothetical accident sequence when the puncture test was oriented to specifically attack the locking ring. A series of tests has been performed that conclusively demonstrates that the specially designed locking ring on the H1616 performs adequately in this environment.

Recent K-shell scaling experiments on the 20 MA Z accelerator at Sandia National Laboratories have shown that large diameter (40 and 55 mm) arrays can be imploded with 80 to 210 wires of titanium or stainless steel. These implosions have produced up to 150 kJ of > 4.5 keV x-rays and 65 kJ of > 6.0 keV x-rays in 7 to 18 ns FWHM pulses. This is a major advance in plasma radiation source (PRS) capability since there is presently limited test capability above 3 keV. In fact, Z produces more > 4.5 keV x-rays than previous aboveground simulators produced at 1.5 keV. Z also produces some 200 kJ of x-rays between 1 and 3 keV in a continuous spectrum for these loads. The measured spectra and yields are consistent with 1-dimensional MHD calculations performed by NRL. Thermoelastic calorimeters, PVDF gauges, and optical impulse gauges have been successfully fielded with these sources.

Sandia National Labs has been investigating the use of rigid polyurethane foam (RPF) for military use, particularly for mine protection for the past two years. Results of explosive experiments and mine/foam interaction experiments are presented. The RPF has proved to be effective in absorbing direct shock from explosives. Quantitative data are presented. As reported elsewhere, it has proved effective in reducing the signature of vehicles passing over anti-tank (AT) mines to prevent the mine from firing. This paper presents the results of experiments done to understand the interaction of RPF with anti-craft (AC) mines during foam formation in shallow water in a scaled surf environment.

We describe use of AlAsSb/AlGaAsSb lattice matched to InP for distributed Bragg reflectors. These structures are integral to several surface normal devices, in particular vertical cavity surface emitting lasers. The high refractive index ratio of these materials allows formation of a highly reflective mirror with relatively few mirror pairs. As a result, we have been able to show for the first time the 77K CW operation of an optically pumped, monolithic, all-epitaxial vertical cavity laser, emitting at 1.56 {mu}m.

Sandia National Laboratories performs systems analysis of high risk, high consequence systems. In particular, Sandia is responsible for the engineering of nuclear weapons, exclusive of the explosive physics package. In meeting this responsibility, Sandia has developed fundamental approaches to safety and a process for evaluating safety based on modeling and simulation. These approaches provide confidence in the safety of our nuclear weapons. Similar concepts may be applied to improve the safety of other high consequence systems.

Further improvements to the Waveform Correlation Event Detection System (WCEDS) developed by Sandia Laboratory have made it possible to test the system on the accepted Comprehensive Test Ban Treaty (CTBT) seismic monitoring network. For our test interval we selected a 24-hour period from December 1996, and chose to use the Reviewed Event Bulletin (REB) produced by the Prototype International Data Center (PIDC) as ground truth for evaluating the results. The network is heterogeneous, consisting of array and three-component sites, and as a result requires more flexible waveform processing algorithms than were available in the first version of the system. For simplicity and superior performance, we opted to use the spatial coherency algorithm of Wagner and Owens (1996) for both types of sites. Preliminary tests indicated that the existing version of WCEDS, which ignored directional information, could not achieve satisfactory detection or location performance for many of the smaller events in the REB, particularly those in the south Pacific where the network coverage is unusually sparse. To achieve an acceptable level of performance, we made modifications to include directional consistency checks for the correlations, making the regions of high correlation much less ambiguous. These checks require the production of continuous azimuth and slowness streams for each station, which is accomplished by means of FK processing for the arrays and power polarization processing for the three-component sites. In addition, we added the capability to use multiple frequency-banded data streams for each site to increase sensitivity to phases whose frequency content changes as a function of distance.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams (inspectors) and Inspected Parties (hosts). Traditional training techniques include lectures, table-top inspections, and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT is used for training both inspectors and hosts to conduct a hypothetical challenge inspection under the Chemical Weapons Convention (CWC). The training covers the entire sequence of events in the challenge inspection regime, from initial notification of an inspection through post-inspection activities. The primary emphasis of the training tool is on conducting the inspection itself, and in particular, implementing the concept of managed access. (Managed access is a technique used to assure the inspectors that the facility is in compliance with the CWC, while at the same time protecting sensitive information unrelated to the CWC.) Information for all of the activities is located in the electronic {open_quotes}Exercise Manual.{close_quotes} In addition, interactive menus are used to negotiate access to each room and to alternate information during the simulated inspection. ACE-IT also demonstrates how various inspection provisions impact compliance determination and the protection of sensitive information.

In this user`s guide, details for running BREAKUP are discussed. BREAKUP allows the widely used overset grid method to be run in a parallel computer environment to achieve faster run times for computational field simulations over complex geometries. The overset grid method permits complex geometries to be divided into separate components. Each component is then gridded independently. The grids are computationally rejoined in a solver via interpolation coefficients used for grid-to-grid communications of boundary data. Overset grids have been in widespread use for many years on serial computers, and several well-known Navier-Stokes flow solvers have been extensively developed and validated to support their use. One drawback of serial overset grid methods has been the extensive compute time required to update flow solutions one grid at a time. Parallelizing the overset grid method overcomes this limitation by updating each grid or subgrid simultaneously. BREAKUP prepares overset grids for parallel processing by subdividing each overset grid into statically load-balanced subgrids. Two-dimensional examples with sample solutions, and three-dimensional examples, are presented.

This report documents the RADTRAD computer code developed for the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Reactor Regulation (NRR) to estimate transport and removal of radionuclides and dose at selected receptors. The document includes a users` guide to the code, a description of the technical basis for the code, the quality assurance and code acceptance testing documentation, and a programmers` guide. The RADTRAD code can be used to estimate the containment release using either the NRC TID-14844 or NUREG-1465 source terms and assumptions, or a user-specified table. In addition, the code can account for a reduction in the quantity of radioactive material due to containment sprays, natural deposition, filters, and other natural and engineered safety features. The RADTRAD code uses a combination of tables and/or numerical models of source term reduction phenomena to determine the time-dependent dose at user-specified locations for a given accident scenario. The code system also provides the inventory, decay chain, and dose conversion factor tables needed for the dose calculation. The RADTRAD code can be used to assess occupational radiation exposures, typically in the control room; to estimate site boundary doses; and to estimate dose attenuation due to modification of a facility or accident sequence.

Design metaphors play an important role in the development of many software projects. However, the influence of metaphors on project functionality, design methodology and the interactions among members of the development team is not well understood. This paper seeks insights into these issues by examining the experiences of a design team in building a system under the influence of a particularly strong design metaphor.

One important application of mobile robots is searching a geographical region to locate the origin of a specific sensible phenomenon. Mapping mine fields, extraterrestrial and undersea exploration, the location of chemical and biological weapons, and the location of explosive devices are just a few potential applications. Teams of robotic bloodhounds have a simple common goal; to converge on the location of the source phenomenon, confirm its intensity, and to remain aggregated around it until directed to take some other action. In cases where human intervention through teleoperation is not possible, the robot team must be deployed in a territory without supervision, requiring an autonomous decentralized coordination strategy. This paper presents the alpha beta coordination strategy, a family of collective search algorithms that are based on dynamic partitioning of the robotic team into two complementary social roles according to a sensor based status measure. Robots in the alpha role are risk takers, motivated to improve their status by exploring new regions of the search space. Robots in the beta role are motivated to improve but are conservative, and tend to remain aggregated and stationary until the alpha robots have identified better regions of the search space. Roles are determined dynamically by each member of the team based on the status of the individual robot relative to the current state of the collective. Partitioning the robot team into alpha and beta roles results in a balance between exploration and exploitation, and can yield collective energy savings and improved resistance to sensor noise and defectors. Alpha robots waste energy exploring new territory, and are more sensitive to the effects of ambient noise and to defectors reporting inflated status. Beta robots conserve energy by moving in a direct path to regions of confirmed high status.

A summary of recent advances in cryogenic-aerosol-based wafer-processing technology for semiconductor wafer cleaning is presented. An argon/nitrogen cryogenic-aerosol-based tool has been developed and optimized for removal of particulate contaminants. The development of the tool involved a combination of theoretical (modeling) and experimental efforts aimed at understanding the mechanisms of aerosol formation and the relation between aerosol characteristics and particle-removal ability. It is observed that the highest cleaning efficiencies are achieved, in general, when the cryogenic aerosol is generated by the explosive atomization of an initially liquid jet of the cryogenic mixture.

Proton implantation into the buried oxide of Si/SiO{sub 2}/Si structures does not introduce mobile protons. The cross section for capture of radiation-induced electrons by mobile protons is two orders of magnitude smaller than for electron capture by trapped holes. The data provide new insights into the atomic mechanisms governing the generation and radiation tolerance of mobile protons in SiO{sub 2}. This can lead to improved techniques for production and radiation hardening of radiation tolerant memory devices.

A sensor system simulation has been developed which aids in the evaluation of a proposed fast framing staring sensor as it will perform in its operational environment. Beginning with a high resolution input image, a sequence of frames at the target sensor resolution are produced using the assumed platform motion and the contribution of various noise sources as input data. The resulting frame sequence can then be used to help define system requirements, to aid algorithm development, and to predict system performance. In order to assess the performance of a sensor system, the radiance measured by the system is modeled using a variety of scenarios. For performance prediction, the modeling effort is directed toward providing the ability to determine the minimum Noise Equivalent Target (NET) intensities for each band of the sensor system. The NET is calculated at the entrance pupil of the instrument in such a way that the results can be applied to a variety of point source targets and collection conditions. The intent is to facilitate further study within the user community as new mission areas and/or targets of interest develop that are not addressed explicitly during sensor conceptual design.

The 91.84Sn-3.33Ag-4.83Bi and 96.5Sn-3.5Ag Pb-free solders were evaluated for surface mount circuit board interconnects. The 63Sn-37Pb solder provided the baseline data. All three solders exhibited suitable manufacturability per a defect analyses of circuit board test vehicles. Thermal cycling had no significant effect on the 91.84Sn-3.33Ag-4.83Bi solder joints. Some degradation in the form of grain boundary sliding was observed in 96.5Sn-3.5Ag and 63Sn-37Pb solder joints. The quality of the solder joint microstructures showed a slight degree of degradation under thermal shock exposure for all of the solders tested. Trends in the solder joint shear strengths could be traced to the presence of Pd in the solder, the source of which was the Pd/Ni finish on the circuit board conductor features. The higher, intrinsic strengths of the Pb-free solders encouraged the failure path to be located in proximity to the solder/substrate interface where Pd combined with Sn to form brittle PdSn{sub 4} particles, resulting in reduced shear strengths.

The telecommunications sector plays a pivotal role in the system of increasingly connected and interdependent networks that make up national infrastructure. An assessment of the probable structure and function of the bit-moving industry in the twenty-first century must include issues associated with the surety of telecommunications. The term surety, as used here, means confidence in the acceptable behavior of a system in both intended and unintended circumstances. This paper outlines various engineering approaches to surety in systems, generally, and in the telecommunications infrastructure, specifically. It uses the experience and expectations of the telecommunications system of the US as an example of the global challenges. The paper examines the principal factors underlying the change to more distributed systems in this sector, assesses surety issues associated with these changes, and suggests several possible strategies for mitigation. It also studies the ramifications of what could happen if this sector became a target for those seeking to compromise a nation`s security and economic well being. Experts in this area generally agree that the U. S. telecommunications sector will eventually respond in a way that meets market demands for surety. Questions remain open, however, about confidence in the telecommunications sector and the nation`s infrastructure during unintended circumstances--such as those posed by information warfare or by cascading software failures. Resolution of these questions is complicated by the lack of clear accountability of the private and the public sectors for the surety of telecommunications.

The research focuses on the measurement of the nanomechanical properties associated with the interphase region of a polymer matrix fiber composite with a nanometer resolution in chemically characterized model composites. The Interfacial Force Microscope (IFM) is employed to measure, with nanometer resolution, the mechanical properties of the interphase region of epoxy/glass fiber composites. The chemistry of the interphase is altered by the adsorption on to the fiber surface a coupling agent, 3-aminopropyltrimethoxy silane ({gamma}-APS) which is known to covalently bond to the glass fiber surface and the epoxy resin. Recent work utilizing FT-IR fiber optic evanescent wave spectroscopy provides a method for the characterization of the interphase chemistry. This technique has been used to investigate the interphase chemistry of epoxy/amine curing agent/amine-terminated organosilane coupling agent/silica optical fiber model composites. This body of work has shown that a substantial fraction of the amine of the organosilane-coupling agent does not participate in a reaction with the epoxy resin. This evidence suggests an interphase that will have mechanical properties significantly different than the bulk epoxy/amine matrix. Previous research has shown that drastic changes occur in the coupling agent chemistry, interphase chemistry, and composite mechanical properties as the amount of adsorbed coupling agent is varied over the industrially relevant range used in this work. A commercially available epoxy resin, EPON 828, and aliphatic amine-curing agent, EPI-CURE 3283, make up the polymer matrix in this study. The reinforcement is silica optical or E-glass fibers.

This report describes a 5 year, $10 million Sandia/Industry project to develop an advanced borehole seismic source for use in oil and gas exploration and production. The development Team included Sandia, Chevron, Amoco, Conoco, Exxon, Raytheon, Pelton, and GRI. The seismic source that was developed is a vertically oriented, axial point force, swept frequency, clamped, reaction-mass vibrator design. It was based on an early Chevron prototype, but the new tool incorporates a number of improvements which make it far superior to the original prototype. The system consists of surface control electronics, a special heavy duty fiber optic wireline and draw works, a cablehead, hydraulic motor/pump module, electronics module, clamp, and axial vibrator module. The tool has a peak output of 7,000 lbs force and a useful frequency range of 5 to 800 Hz. It can operate in fluid filled wells with 5.5-inch or larger casing to depths of 20,000 ft and operating temperatures of 170 C. The tool includes fiber optic telemetry, force and phase control, provisions to add seismic receiver arrays below the source for single well imaging, and provisions for adding other vibrator modules to the tool in the future. The project yielded four important deliverables: a complete advanced borehole seismic source system with all associated field equipment; field demonstration surveys funded by industry showing the utility of the system; industrial sources for all of the hardware; and a new service company set up by their industrial partner to provide commercial surveys.

The use of a fracture mechanics based design for the radioactive material transport (RAM) packagings has been the subject of extensive research for more than a decade. Sandia National Laboratories (SNL) has played an important role in the research and development of the application of this technology. Ductile iron has been internationally accepted as an exemplary material for the demonstration of a fracture mechanics based method of RAM packaging design and therefore is the subject of a large portion of the research discussed in this report. SNL`s extensive research and development program, funded primarily by the U. S. Department of Energy`s Office of Transportation, Energy Management and Analytical Services (EM-76) and in an auxiliary capacity, the office of Civilian Radioactive Waste Management, is summarized in this document along with a summary of the research conducted at other institutions throughout the world. In addition to the research and development work, code and standards development and regulatory positions are also discussed.

Construction of a prestressed concrete containment vessel (PCCV) model is underway as part of a cooperative containment research program at Sandia National Laboratories. The work is co-sponsored by the Nuclear Power Engineering Corporation (NUPEC) of Japan and US Nuclear Regulatory Commission (NRC). Preliminary analyses of the Sandia 1:4 Scale PCCV Model have determined axisymmetric global behavior and have estimated the potential for failure in several areas, including the wall-base juncture and near penetrations. Though the liner tearing failure mode has been emphasized, the assumption of a liner tearing failure mode is largely based on experience with reinforced concrete containments. For the PCCV, the potential for shear failure at or near the liner tearing pressure may be considerable and requires detailed investigation. This paper examines the behavior of the PCCV in the region most susceptible to a radial shear failure, the wall-basemat juncture region. Prediction of shear failure in concrete structures is a difficult goal, both experimentally and analytically. As a structure begins to deform under an applied system of forces that produce shear, other deformation modes such as bending and tension/compression begin to influence the response. Analytically, difficulties lie in characterizing the decrease in shear stiffness and shear stress and in predicting the associated transfer of stress to reinforcement as cracks become wider and more extensive. This paper examines existing methods for representing concrete shear response and existing criteria for predicting shear failure, and it discusses application of these methods and criteria to the study of the 1:4 scale PCCV.

Federal laboratories have successfully filled many roles for the public; however, as the 21st Century nears it is time to rethink and reevaluate how Federal laboratories can better support the public and identify new roles for this class of publicly-owned institutions. The productivity of the Federal laboratory system can be increased by making use of public outcome metrics, by benchmarking laboratories, by deploying innovative new governance models, by partnerships of Federal laboratories with universities and companies, and by accelerating the transition of federal laboratories and the agencies that own them into learning organizations. The authors must learn how government-owned laboratories in other countries serve their public. Taiwan`s government laboratory, Industrial Technology Research Institute, has been particularly successful in promoting economic growth. It is time to stop operating Federal laboratories as monopoly institutions; therefore, competition between Federal laboratories must be promoted. Additionally, Federal laboratories capable of addressing emerging 21st century public problems must be identified and given the challenge of serving the public in innovative new ways. Increased investment in case studies of particular programs at Federal laboratories and research on the public utility of a system of Federal laboratories could lead to increased productivity of laboratories. Elimination of risk-averse Federal laboratory and agency bureaucracies would also have dramatic impact on the productivity of the Federal laboratory system. Appropriately used, the US Federal laboratory system offers the US an innovative advantage over other nations.

Radionuclide transport experiments were carried out using intact cores obtained from the Culebra member of the Rustler Formation inside the Waste Isolation Pilot Plant, Air Intake Shaft. Twenty-seven separate tests are reported here and include experiments with {sup 3}H, {sup 22}Na, {sup 241}Am, {sup 239}Np, {sup 228}Th, {sup 232}U and {sup 241}Pu, and two brine types, AIS and ERDA 6. The {sup 3}H was bound as water and provides a measure of advection, dispersion, and water self-diffusion. The other tracers were injected as dissolved ions at concentrations below solubility limits, except for americium. The objective of the intact rock column flow experiments is to demonstrate and quantify transport retardation coefficients, (R) for the actinides Pu, Am, U, Th and Np, in intact core samples of the Culebra Dolomite. The measured R values are used to estimate partition coefficients, (kd) for the solute species. Those kd values may be compared to values obtained from empirical and mechanistic adsorption batch experiments, to provide predictions of actinide retardation in the Culebra. Three parameters that may influence actinide R values were varied in the experiments; core, brine and flow rate. Testing five separate core samples from four different core borings provided an indication of sample variability. While most testing was performed with Culebra brine, limited tests were carried out with a Salado brine to evaluate the effect of intrusion of those lower waters. Varying flow rate provided an indication of rate dependent solute interactions such as sorption kinetics.

Wind-energy researchers at the National Wind Technology Center (NWTC), representing Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL), are developing a new, light-weight, modular data acquisition unit capable of acquiring long-term, continuous time-series data from small and/or dynamic wind-turbine rotors. The unit utilizes commercial data acquisition hardware, spread-spectrum radio modems, and Global Positioning System receivers, and a custom-built programmable logic device. A prototype of the system is now operational, and initial field deployment is expected this summer. This paper describes the major subsystems comprising the unit, summarizes the current status of the system, and presents the current plans for near-term development of hardware and software.

Electronic sensing circuitry and micro electro mechanical sense elements can be integrated to produce inertial instruments for applications unheard of a few years ago. This paper will describe the Sandia M3EMS fabrication process, inertial instruments that have been fabricated, and the results of initial characterization tests of micro-machined accelerometers.

Micromachining technologies enable the development of low-cost devices capable of sensing motion in a reliable and accurate manner. The development of various surface micromachined accelerometers and gyroscopes to sense motion is an ongoing activity at Sandia National Laboratories. In addition, Sandia has developed a fabrication process for integrating both the micromechanical structures and microelectronics circuitry of Micro-Electro-Mechanical Systems (MEMS) on the same chip. This integrated surface micromachining process provides substantial performance and reliability advantages in the development of MEMS accelerometers and gyros. A Sandia MEMS team developed a single-axis, micromachined silicon accelerometer capable of surviving and measuring very high accelerations, up to 50,000 times the acceleration due to gravity or 50 k-G (actually measured to 46,000 G). The Sandia integrated surface micromachining process was selected for fabrication of the sensor due to the extreme measurement sensitivity potential associated with integrated microelectronics. Measurement electronics capable of measuring at to Farad (10{sup {minus}18} Farad) changes in capacitance were required due to the very small accelerometer proof mass (< 200 {times} 10{sup {minus}9} gram) used in this surface micromachining process. The small proof mass corresponded to small sensor deflections which in turn required very sensitive electronics to enable accurate acceleration measurement over a range of 1 to 50 k-G. A prototype sensor, based on a suspended plate mass configuration, was developed and the details of the design, modeling, and validation of the device will be presented in this paper. The device was analyzed using both conventional lumped parameter modeling techniques and finite element analysis tools. The device was tested and performed well over its design range.