Publications

The thermomechanical fatigue behavior of solder joints is a critical reliability issue in electronic packaging. A need exists for a thorough metallurgical understanding of solder joints in conditions of thermal fatigue. This paper presents a method to test solder joints under conditions of thermomechanical fatigue. This method involves simultaneous imposition of temperature and strain cycles on discrete solder joints in a shear orientation. The stress, microstructure, and number of cycles to failure are monitored. Cycles to failure are determined by a continuous electrical resistance detection method. 60Sn-40Pb and 40Sn-40In-20Pb solder joints were tested using this new method at 20% shear strain. 4 refs., 7 figs.

This report provides an introduction to the capabilities of a new experimental test system recently acquired by Department 1830 and installed into the Organization 1000 bay of the microelectronics Development Laboratory, Building 858. This device - the Nano..delta..Indenter/Trademark/ - is a state of the art ultra-low load indentation hardness tester. It is a computer-controlled load and depth sensing instrument with depth resolution of 0.2 nm and load resolution of 0.3 ..mu..N. Initial testing has now been performed using this machine, verifying that it will be a unique addition to our existing mechanical test capabilities. 3 refs., 8 figs.

From the beginning of the geothermal development program, Sandia has performed and supported research into polycrystalline diamond compact (PDC) bits. These bits are attractive because they are intrinsically efficient in their cutting action (shearing, rather than crushing) and they have no moving parts (eliminating the problems of high-temperature lubricants, bearings, and seals.) This report is a summary description of the analytical and experimental work done by Sandia and our contractors. It describes analysis and laboratory tests of individual cutters and complete bits, as well as full-scale field tests of prototype and commercial bits. The report includes a bibliography of documents giving more detailed information on these topics. 26 refs.

Analyses of the final state of collapse of various types of contact-handled waste drums are required to assess of the performance of the waste storage areas in the Waste Isolation Pilot Plant. To provide data for calculations, tests must use simulated, instead of actual waste. Data on the contents of the principal categories of contact-handled transuranic waste from the Idaho National Engineering Laboratory were used to define standard compositions of simulated waste. Categories of baseline waste will be created by mixing appropriate amounts of the simulants together. Selection of materials is discussed. Methods for estimating the consolidation characteristics of simulated waste are also described. Theoretical solid densities, theoretical solid compressibilities, and initial void volumes of various waste components are estimated, and a method for estimating consolidation curves in the absence of experimental data is described. 9 refs., 14 figs., 11 tabs.

The research and development described in this document were conducted within the US Department of Energy's Solar Thermal Technology Program. The goal of the Solar Thermal Technology Program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. This bibliography cites, with a few additions, all the documents that were published by, or sponsored by, Sandia National Laboratories in support of the Department of Energy's Solar Thermal Technology Program and its Distributed Receiver Project. The timing of this updated bibliography is important because it marks the end of an era in which distributed receiver and central receiver research and development were pursued separately. At the beginning of fiscal year 1989, the Department of Energy initiated a restructured solar thermal research and development strategy. The new program is mission oriented, with core technology development activities supporting the missions. For instance, the advanced electric technology mission has an objective to organize industry, user, and government consortia that will field competitive next-generation solar thermal electric system experiments within five years--regardless of whether the systems are distributed or central receivers; and the concentrator development core activity will develop optical materials and concentrators regardless of application.

This document serves as the proceedings for the annual project review meeting held by Sandia's Photovoltaic Cell Research Division and Photovoltaic Technology Division. It contains information supplied by each organization making a presentation at the meeting, which was held 11-13 July 1989 at the Marriott Hotel in Albuquerque, NM. Information supplied by other Sandia contractor and single-page data sheets generated by the cognizant Sandia Technical Liasion for each contract are also included. Sessions were held to discuss national and international photovoltaic programs, one-sun crystalline silicon cell research, concentrator silicon cell research, concentrator III-V cell research, and concentrating collector development.

The Center for Compound Semiconductor Technology (CCST) was formed within the Solid-State Sciences Directorate at Sandia National Laboratories in 1988, as the culmination of a long-term thrust into compound semiconductor research and technology that began about ten years ago. At that time, it was realized that electronic and optoelectronic devices based on compound semiconductors would be necessary for photonic applications, and that they could provide greater radiation hardness, higher speed, and higher operating temperatures than comparable silicon devices and circuits. It was also realized that a successful program would require the development and integration of materials growth and processing capability, solid-state physics research, and device engineering. The program at Sandia grew steadily from the purchase of the first Molecular beam Epitaxy (MBE) system in 1981, and the discovery of strained-layer superlattices in 1982, to the completion of the Compound Semiconductor Research Laboratory in 1989. To more formally organize this effort, Sandia established the CCST in 1988, aided by $10M of funding from DARPA. The CCST comprises most of the compound semiconductor research and development activities in the Solid-State Sciences Directorate. Ongoing programs are funded by the DOE Office of Military Applications, DOE Basic Energy Sciences, DOE Conservation and Renewable Energy, and the Department of Defense. 15 figs.

Sealing a nuclear waste repository in partially saturated tuff presents unique challenges to assuring performance of sealing components. Design and performance of components for sealing shafts, ramps, drifts, and exploratory boreholes depend on specific features of both the repository design and the site; of particular importance is the hydrologic environment in the unsaturated zone, including the role of fracture flow. Repository design features important to sealing of a repository include the size and location of shaft and ramp accesses, excavation methods, and the underground layout features such as grade (drainage direction) and location relative to geologic structure. Uncertainties about seal components relate to the postclosure environment for the seals, the emplacement methods, the material properties, and the potential performance of the components. An approach has been developed to reduce uncertainties and to increase confidence in seal performance; it includes gathering extensive site characterization data, establishing conservative design requirements, testing seal components in laboratory and field environments, and refining designs of both the seals and the repository before seals are installed. 9 refs., 5 figs., 2 tabs.

Sandia National Laboratories: The Postwar Decade is organized into two major sections: Part 1: Heritage'' and Part 2: Nuclear Ordnance Engineer for the Nation.'' Within this general structure, the narrative connects a series of subjects, beginning with a Prologue that surveys the national and international events leading to development of the atomic bomb and establishment of the national laboratory complex under the Manhattan Engineer District.

Recent experiments on Lawrence Livermore's ATA indicate that there may be problems with the IFR (Ion Focused Regime) transport of the relativistic electron beam (REB) through the ATA accelerator. For beam currents greater than about 7-kA, the beam is observed to be inverse-tailored with the beam radius increasing from beam head to tail. This inverse-tailoring is considered unfavorable for endo- atmospheric beam propagation. An unusual feature of ATA's laser- produced IFR channel is that it has a rectangular cross-section. One possible explanation for the lack of good beam transport may be ion motion in the IFR channel which disrupts the tail of the beam. In this report an ATA-like electron beam, propagating on a laser-ionized rectangular IFR channel is simulated using the 3-D magnetostatic code BUCKSHOT. The simulations demonstrate that non-axisymmetric ion motion, similar to the ion hose instability, can produce an inverse- tailored electron beam similar to those found in the experiment. The simulation results should be relevant to upcoming TROLL experiments with a laser-ionized IFR channel, with several beam parameters similar to ATA's. 1 ref., 22 figs.

In late 1985, the International Atomic Energy Agency (IAEA) requested the US Program for Technical Assistance to IAEA Safeguards (POTAS) to provide a study which examined sealing concepts for application to spent fuel shipping casks. This request was approved, and assigned to Sandia National Laboratories (Sandia). In the course of this study, discussions were held with personnel in the International Safeguards Community who were familiar with the shipping casks used in their States. A number of shipping casks were examined, and discussions were held with two shipping cask manufacturers in the US. As a result of these efforts, it was concluded that the shipping casks provided an extremely good containment, and that many of the existing casks can be effectively sealed by applying the seal to the cask closure bolts/nuts.

A design for a photodetector quantum efficiency measurement test system is presented. The system hardware and control software are explained and the measurement theory is given. A brief discussion of the operation of the prototype is given. Finally, the article concludes with an example of a quantum efficiency measurement of a sample and a discussion of the errors involved in the measurement. 9 refs., 7 figs.

The Magma Energy Program of the US Department of Energy, Geothermal Technology Division, is planning to begin drilling a deep (6 km) exploration well in Long Valley Caldera, California, in September 1988. The location of the well is in the central part of the caldera, coincident with a large number of shallow (5-7 km) geophysical anomalies identified through many independent investigations. Results from the hole will permit the following: direct investigation of the geophysical anomalies interpreted to be magma; investigation of the patterns and conditions of deep fluid circulation and heat transport below the caldera floor; determination of the amount of collapse and subsequent resurgence of the central portion of Long Valley caldera; and determination of the intrusion history of the central plutonic complex beneath the caldera, and establishment of the relationship of intrusive to eruptive events. The hole will thus provide a stringent test of the hypothesis that magma is still present within the central plutonic complex. If the interpretation of geophysical anomalies is confirmed, the hole will provide the first observations of the environment near a large silicic magma chamber. 80 refs., 7 figs., 2 tabs.

A computer code for analyzing four-gage Anelastic Strain Recovery (ASR) data has been modified for use on a personal computer. This code fits the viscoelastic model of Warpinski and Teufel to measured ASR data, calculates the stress orientation directly, and computes stress magnitudes if sufficient input data are available. The code also calculates the stress orientation using strain-rosette equations, and its calculates stress magnitudes using Blanton's approach, assuming sufficient input data are available. The program is written in FORTRAN, compiled with Ryan-McFarland Version 2.4. Graphics use PLOT88 software by Plotworks, Inc., but the graphics software must be obtained by the user because of licensing restrictions. A version without graphics can also be run. This code is available through the National Energy Software Center (NESC), operated by Argonne National Laboratory. 5 refs., 3 figs.

The Sandia downhole seismic source produces vertically polarized shear waves of variable frequency. While the source has been successfully tested in the field, the practicality of the source for reservoir characterization has not been established. The principal question is whether sufficient power can be supplied to the source through practical means so that sufficient energy output can be maintained. Here we investigate the feasibility of several schemes to provide power to the Sandia downhole seismic source. 4 refs., 5 figs., 5 tabs.

Traditionally, pyrolysis combined with infrared, IR, detection of the decomposition products for the analysis of small (<1 mg) samples has been limited due to the size and geometry of commercially available pyrolysis chambers. To reduce the sample size requirements for pyrolysis-IR a system has been designed and built that allows various microgram sized polymer samples to be examined. The design incorporates a commercial pyrolysis system with a small chamber built from readily available parts. Minimal modifications of these components are required to build the system. The micropyrolyzer has been used to successfully identify various filled epoxy samples, such as three Epon 828 samples: 0.46 mg of alumina filled; 0.15 mg of mica filled; and 0.28 mg of glass microballoon, GMB, filled. 7 refs., 6 figs.

The fracture toughness of several ductile cast iron (DCI) alloys has been calculated according to two versions of the ASTM Standard covering the determination of J/sub Ic/. The original version (ASTM E 813-81) had previously been used to establish the relationship between ferritic DCI alloys and the graphite nodule spacing. The J/sub Ic/ values were recalculated by the methods of the revised version of the ASTM Standard (ASME 813-87), and were found to be 5 to 8% higher than those determined by the original standard. A linear regression analysis was used to reaffirm that the fracture toughness is directly related to the graphite nodule size or spacing. 6 refs., 8 figs., 3 tabs.

The lightning literature extant through the end of 1988 has been reviewed and used to develop an updated generic, or baseline, direct-strike lightning environment for nuclear weapon Stockpile-to-Target Sequence documents. The supporting rationale for recommended changes is given, along with a discussion of the interpretation of the environment for weapon nuclear safety assessment. 13 refs., 2 tabs.

An initial feasibility study has been completed on the ultrasonic welding of Tophet C (Ni-24 Fe-16 Cr) bridgewire to Hastelloy C-276 (Ni-16 Cr-15 Mo-4 W) pin material. A key feature of this work is that it employed a hybrid microcircuitry ultrasonic wire bonder. Much greater productivity can be expected from this process compared with traditional bridgewire welding methods. Three different ultrasonic tool designs were investigated. After selection of the best design, pull test data were acquired for both the 1st and 2nd weld locations in both heel and toe directions. Values up to 94% of the bridgewire tensile strength were obtained. With the equipment used both raised and flat bridgewire configurations are possible. While much work is still necessary to prove in the process for production applications, the work completed to date indicates the ultrasonic welding process merits further investigation. 6 figs.

Sandia National Laboratories (SNL), Albuquerque is located south of Albuquerque on Kirtland Air Force Base. Because radionuclides are potentially released in small quantities from its research activities, SNL, Albuquerque has a continuing environmental monitoring program which analyzes for cesium-137, tritium, uranium, alpha emitters, and beta emitters in water, soil, air, and vegetation. A total of 5.23 curies of argon-41 were released as a result of SNL, Albuquerque operations in 1988. The albuquerque population received an estimated 0.04 person-rem from airborne radioactive releases, whereas it received greater than 44,500 person-rem from naturally occurring radionuclides. A nonradioactive effluent monitoring program at SNL, Albuquerque includes groundwater, stormwater and sewage monitoring. Results indicate that the groundwater has not been impacted by the chemical waste landfill. Preliminary testing of stormwater showed that no pollutants were above minimum detectable levels. A program to investigate potential remedial action sites has been started. 47 refs., 12 figs., 19 tabs.

The Tonopah Test Range is located about 140 air miles north of Las Vegas, Nevada, and covers 624 square miles within the Nellis Air Force base Bombing and Gunnery Range. The range is used for various USDOE and USDOD program tests that are critical to national defense. Activities that affect the environment are mainly road construction, preparation of instrumentation sites, and disturbance of the terrain from weapons testing. Monitoring of the test range is done routinely by the US Environmental Protection Agency (EPA) to supplement Sandia's monitoring effort associated with Sandia test activities. EPA monitoring results for 1988 indicate that test range operations do not adversely affect the off-site environment or the public. 14 refs., 2 figs., 11 tabs.

During the period October 1988 through December 1988, a search was made for very high energy gamma rays from the direction of the Crab nebula using the atmospheric Cerenkov technique. The detector consisted of seven-fold arrays of photomultiplier tubes at the focii of two 11-meter diameter solar concentrators situated in Albuquerque, New Mexico. A DC signal was detected from the Crab nebula with a statistical significance of 5.8 sigma after the application of various cuts designed to suppress the background of hadronic showers. A search for a pulsed component failed to identify a significant signal in phase with the radio pulse from the Crab pulsar. These results with a threshold energy of 200 GeV are in substantial agreement with high energy results recently reported by the Mt. Hopkins group. 16 refs., 3 figs., 3 tabs.

A two-dimensional model of melt progression, oxidation and natural convection in reactor core debris beds has been developed. Three fields are considered in the model: vapor, melt and solid. Conservation equations are solved for the species of interest in each field. Momentum equations that are based on Darcy's law are solved for the vapor and the melt and a simplified model is used to calculate the motion of the solid as it settles downward. An energy equation is included that accounts for melting/freezing, convection, conduction, oxidation and decay heating. Key results from a sensitivity study include: (1) gas velocities increase rapidly at the onset of oxidation and subsequently decrease when the bed becomes steam-starved; (2) natural convection flows are sensitive to radial variations in the decay heat; (3) raising the pressure in the bed and the upper plenum increases the amount of steam that is available for oxidation and leads to much higher temperatures and gas velocities; (4) reducing the average particle diameter decreases the permeability and significantly lowers gas velocities; and (5) solutions are sensitive to conditions in the upper plenum and consequently, melt progression models discussed here must be coupled to a mechanistic code, such as MELPROG or SCDAP, in order to analyze specific accident sequences. 33 refs., 20 figs.

One critical issue to be addressed in the compact recirculating linac program concerns optimal beam injection into a racetrack-shaped accelerator. There are at least three candidates, axial beam injection, tangential beam injection, and laser-channel-assisted beam injection. In this report these three approaches are examined using computer simulation techniques. 3 refs., 27 figs., 2 tabs.

This report summarizes the current understanding of the expected long-term behavior of the Waste Isolation Pilot Plant (WIPP) repository and estimates long-term radionuclide doses in a series of six analyses investigating both undisturbed repository (Case I) and performance in response to a relatively high-consequence human intrusion (Case II). It is the result of an intensive effort over a short time. The US Department of Energy (DOE) decided to have Sandia National Laboratories prepare this report as a result of a meeting held January 5, 1989. The conceptual model of the expected long-term behavior of the WIPP repository used in this report was formulated in early to mid January 1989, drawing and understanding developed over the past decade. Numerical modeling of ground-water flow, radionuclide transport, and doses to humans began January 20, 1989 and was completed March 20, 1989. 332 refs., 98 figs., 69 tabs.

The particle code MAGIC and the trajectory code TRAJ were used to model diodes, gaps, and conditioning cells for several of Sandia's linear electron accelerators. In this report we summarize the main results obtained and discuss their significance. 29 refs., 50 figs., 10 tabs.

The US Department of Energy is planning to dispose of transuranic wastes at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. Sandia National Laboratories is responsible for evaluating the compliance of the WIPP with the Environmental Protection Agency's Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). This plan has been developed to present the issues that will be addressed before compliance can be evaluated. These issues examine the procedural nature of the Standard, and the technical requirements for further characterizing the behavior of the disposal system, including uncertainties, to support the compliance assessment. The plan briefly describes the activities that will be conducted prior to 1993 by Sandia to characterize the WIPP disposal system's behavior and predict its performance. 41 refs., 35 figs., 21 tabs.

Computer simulations, using the hydrocode HULL, were performed to analyze a method to discard the sabot and the effectiveness of several designs in reducing the kinetic energy of pusher plates for Davis Gun systems. This study assumed an axisymmetric impact of the pusher plate on one metal and multi-metal annual plates. Based on these simulations, a four petal sabot that is mechanically attached to the penetrator and an aluminum-steel composite target plate are recommended. 12 refs., 27 figs.

The IAEA is increasingly confronted with decisions on how to use operator designed monitoring systems. A major question in the use of such systems focuses on how they may be authenticated. This report identifies four major areas of concern for authentication of an operator designed system. Generic methods to address these areas of concern are presented. Suggestions are also given on design features an operator can incorporate when designing a system which will aid in the application of authentication techniques.

Over 4100 ft (1100 ft oriented) of Mesaverde core was taken during the drilling of the three Multiwell Experiment (MWX) wells, for study in a comprehensive core analysis program. This core traversed five separate depositional environments (shoreline/marine, coastal, paludal, fluvial, and paralic), and almost every major sand in the Mesaverde at the site was sampled. This paper summarizes MWX core analysis and describes the petrophysical properties at the MWX site; reservoir parameters, including permeabilities of naturally fractured core; and mechanical rock properties including stress-related measurements. Some correlations are made between reservoir properties and mineralogy/petrology data. Comparisons are made between the properties of lenticular and blanket sandstone morphologies existing at the site. This paper provides an overview of a complete core analysis in a low-permeability sandstone reservoir. 66 refs., 17 figs. , 9 tabs.

A very simple algorithm is presented that allows particles to be loaded or initialized in a particle simulation code. The algorithm can load particle positions or velocities according to any well- behaved density or distribution function. Sample codes are given in 1, 2, and 3 dimensions. The technique is highly efficient. 2 refs., 9 figs., 3 tabs.

Experiments were run using a PC-100 ion mobility spectrometer and TNT explosive vapor source to evaluate the adsorb-desorb characteristics of select 6.2 mm O.D. by 4.0 mm I.D. by 76.2 mm long glass preconcentrator tubes. This study was done to aid in the continuing search for an efficient preconcentrating device to be used with explosive vapor detecting instruments. These tubes were tested at various sampling rates ranging from 60 to 510 ml/min and the samples were thermally desorbed to provide the maximum output signal. Data showed the tubes with the greatest internal surface area for the explosive molecules to stick to produced the best desorption results, namely the glass wool packed tubes. Correlation between tube type and sampling flows with respect to maximum output signal proved to be significant, along with the individual tube desorption profiles. 23 figs.

Hermes III is a 20-megavolt, 15-terawatt, pulsed accelerator which is available for gamma-ray testing. The purpose of this guide is to serve as a basic source of information for prospective users of Hermes III. Included is a brief discussion of the design and operation of the accelerator and a summary of gamma-ray environmental data. The guide also contains a description of experimental support facilities, data acquisition and analysis systems and general information for users. 6 refs., 16 figs.

Characterizing the explosive dispersal of inert solid particles is of interest in a number of applications. A mixture theory approach is used to calculate the radial motion of the gas-solid mixture as it expands into an infinite atmosphere. Two initial gas-solid configurations are considered. In the first, a core of high pressure gas initially at rest is surrounded by a porous shell of the solid. The other configuration considered is a uniform mixture of solid and gas throughout the sphere. An adaptive finite element method is used to solve the set of partial differential equations for mass, momentum and energy conservation in each phase as well as the compaction equation for the time evolution of solid volume fraction. An adaptive grid scheme is used to refine the mesh to limit discretization errors. This places a fine mesh near the porosity and pressure fronts and greatly reduces the spatial resolution in areas of relatively constant pressure and volume fraction. The dispersal of the solid for the two initial configurations shows quite different behavior. For the gas core and porous shell, the solids are initially compacted to a maximum density of /approximately/80--90% in a very thin region before rapidly dispersing to a broad concentration distribution. For the homogeneous gas-solid sphere, however, there is only a slight compaction region at the leading edge of the expanding gas, and the concentration of solid decays rapidly. 25 refs., 32 figs., 5 tabs.

The purpose of this report is to provide some basic information to beginning users of Department 9140's Computer-Aided Engineering (CAE) workstations. These workstations are all Digital Equipment Corporation (DEC) color VAXstations, and they use the VAX/VMS operating system. This manual shows users how to boot the workstations, login, use the window interface, and use some basic VMS commands. It also discusses some of the CAE software available on the workstations, such as ANVIL-5000. References are given so users can get additional information. 25 refs., 27 figs.

The difficulty of detecting, locating and identifying low-magnitude seismic events has been an ongoing problem. In this note, we describe processing methods that help us to find low-magnitude seismic events. A series of algorithms with beamforming has been developed and has proven effective in helping to discover very low yield events. The beamforming technique consists of determining the array element time delays for the specific source region using previously established events. This allows us to concentrate the array to look at the specified source location. Examples of this type of analysis are provided. In the analysis of seismic data one may be in possession of other information, e.g., newspaper reports of an earthquake. Using this information to concentrate the search for an event will often identify an otherwise overlooked signal. The algorithms for this type of search are incorporated into computer software that includes capabilities for plotting, spectral and signal-to-noise estimation, direction finding, and other functions. 2 refs., 25 figs.

A new program, ELLIPSE, for the analysis of ellipsometric data is described. The program is interactive and includes on-line help, performs explicit error analysis for single-angle-of-incidence measurements, allows the input of four-zone null data, and performs least-squares analysis of multiple-angle-of-incidence data. Solutions for the transparent-film-on-substrate model are obtained using decoupled equations for film thickness and index. No initial guess is required for thickness, and the algorithm is insensitive to the initial guess for film index. This document combines the user's manual and program description for ELLIPSE, and includes several examples of its use. 11 refs.

One of the factors considered in the design of critical concrete structures is the estimation of the global elasto-plastic structural response caused by the accidental impact of an aircraft. To estimate the response of the structure, the impact force (the force versus time relationship) must be known. Previous analytical studies have derived the forcing function using the impact velocity of the aircraft and the calculated mass and strength distribution of the aircraft. This paper describes a test conducted on April 19, 1988, at an existing rocket sled facility at Sandia National Laboratories in Albuquerque, New Mexico, USA, in which an actual F-4 Phantom aircraft was impacted at a nominal velocity of 215 m/s into an essentially rigid block of concrete. This was accomplished by supporting the F-4 on four struts that were attached to the sled track by carriage shoes to direct the path of the aircraft. Propulsion was accomplished by two stages of rockets. The concrete target was 'floated' on a set of air bearings. Data acquisition consisted of measurements of the acceleration of the fuselage and engines of the F-4, and measurements of the displacement, velocity and acceleration of the concrete target. High-speed photography recorded the impact process and also permitted the determination of the impact velocity. This paper describes the test plan, method and results, while a companion paper discusses the analyses of the results. 6 refs., 11 figs.

A related function takes place in situations where an intermediate memory device may be used to store the unique signal information. In this case, ''verification patterns'' are communicated back to the source as status of the memory in which the unique signal is stored. If properly used, unique signals and verification patterns can support acceptable abnormal-environment nuclear detonation safety. If improperly used, there is danger of a false sense of complacency. In this report, the potential danger of misunderstanding the implications of abnormal environments is described. Unfortunately, a number of common normal-environment assumptions and analytical techniques are sometimes applied to abnormal environment situations. Several of these are shown to be misleading for assessing unique signal performance in abnormal environments. Misapplied approaches can encourage communication system design features that may seriously degrade nuclear detonation safety. 8 refs., 10 figs.

To analytically model soldering and welding processes it is necessary to track the deformation of a material as it changes from a solid to a liquid and then back again to a solid. Because it is the residual stress state in the solid that is of primary interest, the most suitable tools for studying this class of problems appear to be Lagrangian finite element codes that are typically used in the analysis of solids. It is possible to obtain solutions to hydrostatic fluids problems using a Lagrangian finite element code by allowing the ''fluid'' phase of the material to sustain a deviatoric stress component that is very small in magnitude relative to the hydrostatic pressure that exists in the material. The capability to model surface tension phenomena was added to the finite element code SANCHO. SANCHO is a Lagrangian finite element code that uses a dynamic relaxation scheme to solve nonlinear problems involving quasistatic loading of two-dimensional solids. SANCHO is formulated so that it properly accounts for large deformations. This report details the theory and implementation of the method used to model surface tension. With this new capability, SANCHO can be used to solve surface tension problems that are more complex than the problems that can be treated with other more tradition methods of surface tension analysis. 3 refs., 10 figs.

GEN3D is a three-dimensional mesh generation program. The three- dimensional mesh is generated by mapping a two-dimensional mesh into three dimensions according to one of four types of transformations: translating, rotating, mapping onto a spherical surface, and mapping onto a cylindrical surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, and revolving about an axis. GEN3D can be used to mesh geometries that are axisymmetric or planar, but, due to three-dimensional loading or boundary conditions, require a three-dimensional finite element mesh and analysis. More importantly, it can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two-dimensional geometries. The code GJOIN is then used to join the separate sections into a single body. GEN3D reads and writes two-dimensional and three- dimensional mesh databases in the GENESIS database format; therefore, it is compatible with the preprocessing, postprocessing,and analysis codes used by the Engineering Analysis Department at Sandia National Laboratories, Albuquerque, NM. 19 refs., 7 figs.

The LeCroy 6880 uses 32 interleaved linear CCD arrays to digitize data up to 250 MHz. Each CCD array has different offset, droop, and gain characteristics. To obtain usable data once the outputs from the CCDs are interleaved, the raw data must be ''corrected'' to account for these different characteristics. This report describes the DC corrections used on raw data to compensate for the differences in CCD characteristics. 5 refs., 12 figs.

An electron moving in the magnetic field generated by a current-carrying rod will drift in the direction defined by the rod. The motion can be characterized by two dimensionless parameters,/var epsilon/ = 2eI/mc/sup 3/..gamma beta.. and xi = (v/sub /phi///v)exp(v/sub z///var epsilon/v). The drift velocity can be computed by numerical integration for arbitrary values of /var epsilon/ and xi. Analytic solutions are derived for the limiting cases xi = 0 and /vert bar/xi/vert bar/ = xi/sub MAX/. Series solutions are derived that are accurate in the limit /vert bar/xi//var epsilon//vert bar/ << 1. A simple algorithm is developed that has an error of less than +- 0.08% for /var epsilon/ greater than or equal to 2. 14 refs., 18 figs.

This report discusses the application of finite-element methods to the solution of magnetostatic field problems. A brief description is given of the finite-element representation of the magnetostatic field. Two computer codes which solve this problem are described. The code MAGNUM is commercially available and the code ISO is a Sandia in-house product. Both codes are currently available on the Sandia CRAY. Some general remarks are presented on modeling techniques and boundary conditions. A new method for estimating solenoid magnetic forces and dynamic response is described. A suite of codes for generating various electromagnetic devices is briefly discussed. Finally, some numerical results are presented. 6 refs., 10 figs.

Sandia National Laboratories operates the Primary Standards Laboratory (PSL) for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the second half of 1988 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program. 8 refs.

The FAC-SIM factory simulation environment provides systems analysis capabilities during the natural top-down design process for industrial facilities. Models can be constructed and simulations run for coarse descriptions of facility systems and process operations. Detail can be added incrementally to the models as the design progresses. Simulations run with FAC-SIM can identify critical subsystems and determine the impacts of variations in system design and operations. The graphical and hierarchical representations of both physical objects and operations are the unique features of FAC-SIM that permit ease of top-down simulations. This paper describes the FAC-SIM environment and its use in the ongoing development of the Repository Simulation System, REPSIMS, for the analysis of surface facilities at geological repositories for radioactive waste. 13 refs., 5 figs., 5 tabs.

Nuclear deterrence, a cornerstone of US national security policy, has helped prevent global conflict for over 40 years. The DOE and DoD share responsibility for this vital part of national security. The US will continue to rely on nuclear deterrence for the foreseeable future. In the late 1950s, Sandia developed satellite-borne nuclear burst detection systems to support the treaty banning atmospheric nuclear tests. This activity has continued to expand and diversify. When the Non-Proliferation Treaty was ratified in 1970, we began to develop technologies to protect nuclear materials from falling into unauthorized hands. This program grew and now includes systems for monitoring the movement and storage of nuclear materials, detecting tampering, and transmiting sensitive data securely. In the late 1970s, negotiations to further limit underground nuclear testing were being actively pursued. In less than 18 months, we fielded the National Seismic Station, an unattended observatory for in-country monitoring of nuclear tests. In the mid-l980s, arms-control interest shifted to facility monitoring and on-site inspection. Our Technical On-site Inspection Facility is the national test bed for perimeter and portal monitoring technology and the prototype for the inspection portal that was recently installed in the USSR under the Intermediate-Range Nuclear Forces accord. The articles in the special issue of Sundiu Technology describe some of our current contributions to verification technology. This work supports the US policy to seek realistic arms control agreements while maintaining our national security.

The Department of Energy sponsored a workshop on the use of burnup credit in the criticality design of spent fuel shipping casks on February 21 and 22, 1988. Twenty-five different presentations on many related topics were conducted, including the effects of burnup credit on the design and operation of spent fuel storage pools, casks and modules, and shipping casks; analysis and physics issues related to burnup credit; regulatory issues and criticality safety; economic incentives and risks associated with burnup credit; and methods for verifying spent fuel characteristics. An abbreviated version of the DOE workshop was repeated as a special session at the November 1988 American Nuclear Society Meeting in Washington, DC. Each of the invited speakers prepared detailed papers on his or her respective topic. The individual papers have been cataloged separately.

The goals of our Basic Energy Sciences (BES) Materials Science Program at Sandia are: (1) Perform basic, forefront interdisciplinary research using the capabilities of several organizations. (2) Choose programs broadly complementary to Sandia's weapons laboratory mission, but separably identifiable. (3) Perform research in a setting which enhances technological impact because of Sandia's spectrum of basic research, applied research and development engineering. (4) Use large, capital-intensive research facilities not usually found at universities. The BES Materials Science program at Sandia Albuquerque has the central theme of Scientifically Tailored Materials. The major objective of this program is to combine Sandia's expertise and capabilities in the areas of solid state sciences, advanced atomic-level diagnostics, and materials-processing science to produce new classes of tailorable materials for the US energy industry, the electronics industry and for defense needs. Current research in this program includes ion-implantation-modified materials, physics and chemistry of ceramics, tailored surfaces for materials applications, strained-layer semiconductors, chemical vapor deposition, surface photo kinetics, organic and high-temperature superconductors, advanced growth techniques for improved semiconductor structures and boron-rich very high temperature semiconductors.

The Annual Solar Thermal Technology Research and Development Conference is being held at the Holiday Inn Crowne Plaza in Arlington, Virgina, Marh 8 and 9, 1989. This year the conference is meeting in conjunction with SOLTECH '89. SOLTECH '89 is a jointly sponsored meeting of the Solar Energy Industries Association, Interstate Solar Coordination Council, Sandia National Laboratories and the Solar Energy Research Institute. This report contains the agenda, extended abstracts and most significant visual aids used by the speakers during the Solar Thermal Technology research and development sessions. The program is divided into three sessions: Solar Electric Technology, Non-Electric Research and Development and Applications, and Concentrators.