The electronics industry has relied heavily upon the use of soldering for both package construction and circuit assembly. The solder attachment of devices onto printed circuit boards and ceramic microcircuits has supported the high volume manufacturing processes responsible for low cost, high quality consumer products and military hardware. Defects incurred during the manufacturing process are minimized by the proper selection of solder alloys, substrate materials and process parameters. Prototyping efforts are then used to evaluate the manufacturability of the chosen material systems. Once manufacturing feasibility has been established, service reliability of the final product is evaluated through accelerated testing procedures.
To deliver high bandwidth, a ubiquitous inter-/intra-building cable plant consisting of single mode and multimode fiber as well as twisted pair copper is required. The selection of the ``glue`` to transport and interconnect distributed LANs with central facility resources over a pervasive cable plant is the focus of this paper. A description of the traditional problems that must be overcome to provide very high bandwidth beyond the narrow confines of a computer center is given. The applicability of Asynchronous Transfer Mode (ATM) switching (interconnection) and Synchronous Optical NETwork (SONET) (transport) for high bandwidth delivery is described using the environment and requirements of Sandia National Laboratories. Other methods for distributing high data rates are compared and contrasted. Sandia is implementing a standards based foundation utilizing a pervasive single mode fiber cable plant, SONET transport, and ATM switching to meet the goals of gigabit networking.
The intent of this report is to examine the performance of the Deployable Seismic Verification System (DSVS) developed by the Department of Energy (DOE) through its national laboratories to support monitoring of underground nuclear test treaties. A DSVS was installed at the Pinedale Seismic Research Facility (PSRF) near Boulder, Wyoming during 1991 and 1992. This includes a description of the system and the deployment site. System performance was studied by looking at four areas: system noise, seismic response, state of health (SOH) and operational capabilities.
The three papers in this report were presented at the second international workshop to feature the Waste Isolation Pilot Plant (WIPP) Materials Interface Interactions Test (MIIT). This Workshop on In Situ Tests on Radioactive Waste Forms and Engineered Barriers was held in Corsendonk, Belgium, on October 13--16, 1992, and was sponsored by the Commission of the European Communities (CEC). The Studiecentrum voor Kernenergie/Centre D`Energie Nucleaire (SCK/CEN, Belgium), and the US Department of Energy (via Savannah River) also cosponsored this workshop. Workshop participants from Belgium, France, Germany, Sweden, and the United States gathered to discuss the status, results and overviews of the MIIT program. Nine of the twenty-five total workshop papers were presented on the status and results from the WIPP MIIT program after the five-year in situ conclusion of the program. The total number of published MIIT papers is now up to almost forty. Posttest laboratory analyses are still in progress at multiple participating laboratories. The first MIIT paper in this document, by Wicks and Molecke, provides an overview of the entire test program and focuses on the waste form samples. The second paper, by Molecke and Wicks, concentrates on technical details and repository relevant observations on the in situ conduct, sampling, and termination operations of the MIIT. The third paper, by Sorensen and Molecke, presents and summarizes the available laboratory, posttest corrosion data and results for all of the candidate waste container or overpack metal specimens included in the MIIT program.
This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.
Sandia National Laboratories, New Mexico, conducts the Utility Battery Storage Systems Program, which is sponsored by the US Department of Energy`s Office of Energy Management. As a part of this program, four utility-specific systems studies were conducted to identify potential battery energy storage applications within each utility network and estimate the related benefits. This report contains the results of these systems studies.
Solid state silicon-29 nuclear magnetic resonance (NMR) spectroscopy has been used to characterize the formation of high pressure silica polymorphs and amorphous material associated with the shocked Coconino Sandstone from Meteor Crater, Arizona. Five samples of the sandstone were obtained from several locations at the crater to represent a range of shock conditions associated with the hypervelocity impact of a 30 m-diameter meteorite. The NMR spectra for these powdered materials exhibit peaks assigned to quartz, coesite, stishovite, and glass. A new resonance in two of the moderately shocked samples is also observed. This resonance has been identified as a densified form of amorphous silica with silicon in tetrahedra with one hydroxyl group. Such a phase is evidence for a shock-induced reaction between quartz and steam under high pressure conditions.
Sandia has developed an advanced operational control system approach, called Graphical Programming, to design and operate robot systems in unstructured environments. This Graphical Programming approach produces robot systems that are faster to develop and use, safer in operation, and cheaper overall than altemative teleoperation or autonomous robot control systems. This approach uses 3-D visualization and simulation software with intuitive operator interfaces for the programming and control of complex robotic systems. Supervisor software modules allow an operator to command and simulate complex tasks in a graphic preview mode and, when acceptable, command the actual robots and monitor their motions with the graphic system. Graphical Programming Supervisors maintain registration with the real world and allow the robot to perform tasks that cannot be accurately represented with models alone by using a combination of model and sensor-based control. All of these capabilities when combined result in a flexible system which is readily able to meet the demands called for in construction automation. This paper describes the Graphical Programming approach, several example control systems that use Graphical Programming, key features necessary for implementing successful Graphical Programming systems, and specific examples of applying these systems to robotic operations.
High spatial resoslution x-ray microanalysis in the analytical electron microscope (AEM) can be used to determine chemical composition on spatial scales of < 50 nm. Simple scattering models have the drawback of being incapable of treating electron scattering in inhomogeneous specimens, such as at phase interfaces or grain boundary segregation. The best method for calculating electron scattering and x-ray generation function is by Mone Carlo methods. Two examples are discussed: a phase interface in an Fe-Ni-Cr alloy, and grain boundary segregation using a 0.3 nm Cu slab in a 25 nm Al film (the slab is parallel to incident electron beam). It is concluded that high spatial resolution x-ray microanalysis can achieve near atomic resolution, but that massively parallel Monte Carlo models for electron scattering and a well characterized electron beam are needed.
Under a Cooperative Agreement between the Commission of European Communities (CEC) and the U. S. Department of Energy (DOE), the Joint Research Centre, (JRC) ISPRA, and Sandia National Laboratories (SNL) have been cooperating in the development of Containment and Surveillance equipment for a number of years. With recent technology advancements, this cooperation is expanding into the areas of Data Authentication, Safeguards Data Networks, Integrated Systems, and Image Processing. This paper will describe recently expanded efforts in connecting the Integrated Monitoring System designed by SNL to the Computer Aided Video Surveillance System designed by JRC. An SNL Modular Video Authentication System was furnished to test in the video circuitry of the Computer Aided Video Surveillance System. The two systems will remain at JRC for demonstrations, training, and future development activities.
Effective application of pan-tilt cameras in alarm assessment systems requires that the overall system design be such that any threat for which the system is designed will be within the field of view of the camera for a sufficiently long time for the assessment of the alarm to be performed. The assessment of alarms in large, unobstructed areas requires a different type of analysis than traditionally used for clear zones between fences along fixed perimeters where an intruder`s possible location is well defined. This paper presents a design methodology which integrates the threat characteristics, sensor detection pattern, system response time, and optics geometry considerations to identify all feasible locations for camera placement for effective assessment of large, unobstructed areas. The methodology also can be used to evaluate tradeoffs among these various considerations to improve candidate designs.
In this study we have developed the techniques to investigate the hydrodynamic response of high-strength ceramics by mixing these powders with copper powder, preparing compacts, and performing shock compression tests on these mixtures. Hydrodynamics properties of silicon carbide, titanium diboride, and boron carbide to 30 GPa were examined by this method, and hydrodynamic compression data for these ceramics have been determined. We have concluded, however, that the measurement method is sensitive to sample preparation and uncertainties in shock wave measurements. Application of the experimental technique is difficult and further efforts are needed.
Developments are reported in both experimental and numerical capabilities for characterizing the debris spray produced in penetration events. We have performed a series of high-velocity experiments specifically designed to examine the fragmentation of the projectile during impact. High-strength, well-characterized steel spheres (6.35 mm diameter) were launched with a two-stage light-gas gun to velocities in the range of 3 to 5 km/s. Normal impact with PMMA plates, thicknesses of 0.6 to 11 mm, applied impulsive loads of various amplitudes and durations to the steel sphere. Multiple flash radiography diagnostics and recovery techniques were used to assess size, velocity, trajectory and statistics of the impact-induced fragment debris. Damage modes to the primary target plate (plastic) and to a secondary target plate (aluminum) were also evaluated. Dynamic fragmentation theories, based on energy-balance principles, were used to evaluate local material deformation and fracture state information from CTH, a three-dimensional Eulerian solid dynamics shock wave propagation code. The local fragment characterization of the material defines a weighted fragment size distribution, and the sum of these distributions provides a composite particle size distribution for the steel sphere. The calculated axial and radial velocity changes agree well with experimental data, and the calculated fragment sizes are in qualitative agreement with the radiographic data. A secondary effort involved the experimental and computational analyses of normal and oblique copper ball impacts on steel target plates. High-resolution radiography and witness plate diagnostics provided impact motion and statistical fragment size data. CTH simulations were performed to test computational models and numerical methods.
Today`s integrated circuits are so complex that it is often necessary to have access to the layouts and schematics when performing voltage contrast, cross sectioning, light emission, mechanical probing, optical beam induced current, and even simple SEM and Optical Examination. To deal with these issues, Sandia National Laboratories is developing an advanced failure analysis laboratory networking scheme to provide computer control, layout navigation, schematic navigation, and report generation on each of the major pieces of failure analysis equipment. This concept is known as an Integrated Diagnostic Environment or IDE. An integrated diagnostic environment is an environment where failure analysis equipment is computer-controlled and linked by a high speed network. The network allows CAD databases to be shared between instruments, improving the failure analyst`s productivity on each analysis task. At Sandia, we are implementing this concept using SUN Sparcstation computers running Schlumberger`s IDE software. To date, we have incorporated our electron beam prober and light emission system into the environment. We will soon add our scanning optical microscope and focused ion beam system and eventually add our optical microscope and microprobe station into the network. There are a number of issues to consider when implementing an Integrated Diagnostic Environment; these are discussed in detail in this paper.
This paper describes the development and use of the Multi-Axis Seam racking (MAST) sensor for tracking seams or other features in real-time. Four independent, spatially-distributed electric fields are used to sense changes in the relative position of the sensor and the workpiece. The MAST sensor is very inexpensive compared with commercially available seam tracking sensors. It can be used in systems to perform cost-effective small-lot manufacturing operations in a faster, more consistent manner. The MAST sensor is used in an automated system for dispensing braze paste during a rocket nozzle fabrication process.
The ability for a communications network to realize arbitrary communications patterns can be expensive both in terms of hardware and in terms of system software. One might instead ask whether a system can be built which performs well for a given application program. In this paper we look at the question of when a set of communications patterns is suitable for fast realization on a given network. In particular we look at which patterns are realizable quickly on a mesh. Contrary to common wisdom, transpose is efficiently realizable on a mesh. However, some other important patterns such as shuffle are not.
The Milling Assistant (MA) programming system demonstrates the automated development of tool paths for Numerical Control (NC) machine tools. By integrating a Case-Based Reasoning decision processor with a commercial CAD/CAM software, intelligent tool path files for milled and point-to-point features can be created. The operational system is capable of reducing the time required to program a variety of parts and improving product quality by collecting and utilizing ``best of practice`` machining strategies.
The US Department of Energy (DOE) is sponsoring the Utility Battery Storage Systems Program at Sandia National Laboratories and its contractors. This program is specifically aimed at developing battery energy storage systems for electric utility applications commencing in the mid to late 1990s. One factory-integrated utility battery system and three battery technologies: sodium/sulfur, zinc/bromine, and lead-acid are being developed under this program. In the last few years the emphasis of this program has focused on battery system development. This emphasis has included greater interactions with utilities to define application requirements. Recent activities have identified specific applications of battery energy storage in certain utility systems and quantified the value of these applications to these utility companies. In part due to these activities, battery energy storage is no longer regarded by utilities as a load-leveling resource only, but as a multifunction, energy management resource.
The US Department of Energy is sponsoring the development of battery energy storage systems for electric utilities. An important part of this DOE program is the engineering of the battery subsystem. Because lower costs are possible and less space is required compared with conventional battery technologies, two advanced battery systems are being developed: sodium/sulfur and zinc/bromine. A brief description of the development approach being followed along with the current status of the sodium/sulfur technology is described in this paper. Of immediate relevance, a factory integrated modular sodium/sulfur system has been designed that incorporates many of the advantages of this technology. Each module (designated as NAS-P{sub AC}) combines a 600-kWh sodium/sulfur battery, a 300 kW power converter and a control system. In addition to the potential for low life-cycle cost, other specific benefits include excellent portability and an installed system-level footprint that is about 20% of an equivalent system using lead-acid batteries. The sodium/sulfur battery is designed to deliver its rated energy for 1500 cycles or 5 years of maintenance-free operation.
Sandia National Laboratories determined that the most effective method to address records management initiatives would be through a single, comprehensive facilities wide records inventory and retention schedule project. The logistic of such an undertaking (estimated at 425,000 linear feet) are demanding. The relatively short time frame required for completion and the project`s size called for sound, up front planning by Sandia and ultimately the support of an outside contractor for qualified resources to execute the plan.
Development of a high-temperature, superconducting, synchronous motor for large applications (>1000 HP) could offer significant electrical power savings for industrial users. Presently 60% of all electric power generated in the United States is converted by electric motors. A large part of two power is utilized by motors 1000 HP or larger. The use of high-temperature superconducting materials with critical temperatures above that of liquid nitrogen (77 K) in the field winding would reduce the losses in these motors significantly, and therefore, would have a definite impact on the electrical power usage in the US. These motors will be 1/3 to 1/2 the size of conventional motors of similar power and, thus, offer potential savings in materials and floor space. The cooling of the superconducting materials in the field windings of the rotor presents a unique application of cryogenic engineering. The rotational velocity results in significant radial pressure gradients that affect the flow distribution of the cryogen. The internal pressure fields can result in significant nonuniformities in the two-phase flow of the coolant. Due to the variable speed design, the flow distribution has the potential to change during operation. A multiphase-flow computer model of the cryogenic cooling is developed to calculate the boiling heat transfer and phase distribution of the nitrogen coolant in the motor. The model accounts for unequal phase velocities and nonuniform cooling requirements of the rotor. The unequal radial pressure gradients in the inlet and outlet headers result in a larger driving force for flow in the outer cooling channels. The effect of this must be accounted for in the design of the motor. Continuing improvements of the model will allow the investigation of the transient thermal issues associated with localized quenching of the superconducting components of the motor.
The deliverability of a reservoir depends primarily on its permeability, which, in many reservoirs, is controlled by a combination of natural fractures and the in situ stresses. Therefore it is important to be able to predict which parts of a basin are most likely to contain naturally fractured strata, what the characteristics of those fractures might be, and what the most likely in situ stresses are at a given location. This paper presents a set of geologic criteria that can be superimposed onto factors, such as levels of maturation and porosity development, in order to predict whether fractures are present once the likelihood of petroleum presence and reservoir development have been determined. Stress causes fracturing, but stresses are not permanent. A natural-fracture permeability pathway opened by one system of stresses may be held open by those stresses, or narrowed or even closed by changes of the stress to an oblique or normal orientation. The origin of stresses and stress anisotropies in a basin, the potential for stress to create natural fractures, and the causes of stress reorientation are examined in this paper. The appendices to this paper present specific techniques for exploiting and characterizing natural fractures, for measuring the present-day in situ stresses, and for reconstructing a computerized stress history for a basin.
By extracting and analyzing measurement (variables) data from portal metal detectors whenever possible instead of the more typical ``alarm``/``no-alarm`` (attributes or binomial) data, we can be more informed about metal detector health with fewer tests. This testing methodology discussed in this report is an alternative to the typical binomial testing and in many ways is far superior.
Varistor material is currently supplied by a single commercial source. The chem-prep varistor process was developed as a backup/replacement. With the transfer of the process to the production facility, studies were made to verify that the process is stable in manufacturing. Process variables are the precursors oxalic acid, NaOH, and ZnCl{sub 2}. Process stability was determined by comparing assay uncertainty region with precipitant/ZnCl{sub 2} compositional region meeting electrical and physical property specifications. Assay variability was assessed by conducting a round robin; standard deviations of repeated assays of the same sample was 0.1 wt% by the same labs; 0.1-0.4 wt% among laboratories. A mixture experiment was then conducted to assess the effects of the precipitants/ZnCl{sub 2} on breakdown field, nonlinearity coefficient, and bulk density. Results indicate that the chem-prep process can be stable; however the nominal target composition was on the edge of the composition region, and it was moved to the center of the large region with acceptable electrical and physical properties. Tests of unpotted component rods made from the new composition met all specifications. 8 refs, 10 figs, 10 tabs.