Publications

The National Center for Advanced Information Components Manufacturing (NCAICM) was established by congressional appropriation in the FY93 Defense Appropriation Bill. The Center, located at Sandia National Laboratories in Albuquerque, NM, is funded through the Advanced Research Projects Agency (ARPA). The technical focus of NCAICM is emissive flat panel displays and associated microelectronics, specifically targeting manufacturing issues such as materials, processes, equipment, and software tools. This Center is a new avenue of collaboration between ARPA and the Department of Energy (DOE). It will help the government meet its obligation to develop dual-use capabilities for the defense and civilian sectors of the economy and provide a new method for cooperation and collaboration between the federal government and American industry. In particular, one of NCAICM`s goals is to provide industry access to the broad resource base available at three DOE Defense Programs laboratories -- Sandia National Laboratories, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory.

The use of multi-source power systems, ``hybrids,`` is one of the fastest growing, potentially significant markets for photovoltaic (PV) system technology today. Cost-effective applications today include remote facility power, remote area power supplies, remote home and village power, and power for dedicated electrical loads such as communications systems. This market sector is anticipated to be one of the most important growth opportunities for PV over the next five years. The US Department of Energy (USDOE) and Sandia National Laboratories (SNL) are currently engaged in an effort to accelerate the adoption of market-driven PV hybrid power systems and to effectively integrate PV with other energy sources. This paper provides details of this development and the ongoing hybrid activities in the United States. Hybrid systems are the primary focus of this paper.

Infrared (IR) reflection spectroscopy has been shown to be useful for making rapid and nondestructive quantitative determinations of B and P contents and film thickness for borophosphosilicate glass (BPSG) thin films on silicon monitor wafers. Preliminary data also show that similarly precise determinations can be made for BPSG films on device wafers.

A low pressure chemical vapor deposition (LPCVD) process for depositing W{sub X}B{sub (1-X)} films from WF{sub 6} and B{sub 2}H{sub 6} is described. The depositions were performed in a cold wall reactor on 6 in. Si wafers at 400C. During deposition, pressure was maintained at a fixed level in the range of 200 to 260 mTorr. Ratio of WF{sub 6}/B{sub 2}H{sub 6} was varied from 0.05 to 1.07. Carrier gas was either 100 sccm of Ar with a gas flow of 308 to 591 sccm, or 2000 sccm of Ar and 2000 sccm of H{sub 2} with the overall gas flow from 4213 to 4452 sccm. Two stable deposition regions were found separated by an unstable region that produced non-uniform films. The B-rich films produced in one of the stable deposition regions had W concentrations of 30 at.% and resistivities between 200 and 300 {mu}ohm{center_dot}cm. The W-rich films produced in the other stable deposition region had W concentrations of 80 at.% and resistivities of 100 {mu}ohm{center_dot}cm. As-deposited films had densities similar to bulk material of similar stoichiometry. Barrier properties of the films against diffusion of Cu to 700C in vacuum were measured by 4-point probe. Also, annealing was carried out to 900C in order to determine phases formed as the films crystallize. These studies indicate that W{sub X}B{sub (1-X)} films may be useful barriers in ULSI metallization applications.

A relatively high-speed I{sub DDQ} measurement circuit called QuiC-Mon is described. Depending upon IC settling times, upper measurement rates range from 50 kHz to 250 kHz at 100 nA resolution. It provides an inexpensive solution for fast, sensitive I{sub DDQ} measurements in CMOS IC wafer probe or packaged part production testing.

Sandia National Laboratories operates the Primary Standards Laboratory for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the first half of 1993 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program.

Sandia`s mission to explore technology that enhances US nuclear weapons capabilities has been the primary impetus for the development of a class of inertial measurement units not available commercially. The newest member of the family is the Ring Laser Gyro Assembly. The product of a five-year joint effort by Sandia and Honeywell`s Space and Strategic Systems Operation, the RLGA is a small, one-nautical-mile-per-hour-class inertial measurement unit that consumes only 16 watts - attributes that are important to a guidance and control capability for new or existing weapons. These same attributes led the Central Inertial Guidance Test Facility at Holloman Air Force Base to select the RLGA for their newest test instrumentation pod. The RLGA sensor assembly is composed of three Honeywell ring laser gyroscopes and three Sundstrand Data Control accelerometers that are selected from three types according to the user`s acceleration range and accuracy needs.

The objectives of this program are (1) to use and refine a basinal analysis methodology for natural fracture exploration and exploitation, and (2) to determine the important characteritics of natural fracture systems for their use in completion, stimulation and production operations. Continuing work on this project has demonstrated that natural fracture systems and their flow characteristics can be defined by a thorough study of well and outcrop data within a basin. Outcrop data provides key information on fracture sets and lithologic controls, but some fracture sets found in the outcrop may not exist at depth. Well log and core data provide the important reservoir information to obtain the correct synthesis of the fracture data. In situ stress information is then linked with the natural fracture studies to define permeability anisotropy and stimulation effectiveness. All of these elements require field data, and in the cases of logs, core, and well test data, the cooperation of an operator.

Short communication.

The magnetic and structural phase diagrams of the La{sub 2}CuO{sub 4+{delta}} system and the La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} are reviewed, with emphasis on recent results obtained from magnetic and structural neutron diffraction, thermogravimetric analysis, iodometric titration, magnetic susceptibility {chi}(T), and {sup 129}La nuclear quadrupole resonance (NQR) measurements.

The authors employ NMR and NQR spectroscopy as probes of local structure and charge environments in metallic La{sub 2}CuO{sub 4+{delta}} ({Tc} = 38 K). They discuss the effect of annealing the sample at various temperatures T{sub a} ({Tc} < T{sub a} < 300K) on the superconducting {Tc}. The dependence of {Tc} on annealing indicates that annealing allows the development of structural order which is important for {Tc}. The {sup 139}La quadrupole frequency, {nu}{sub Q} is smaller than in undoped materials. This is unexpected and may indicate a smaller charge on the apex oxygen in the doped material and thus a different distribution of charge between the La-O layer to the planes. The further, rapid decrease in {nu}{sub Q} just above {Tc} indicates that temperature dependent charge redistribution is occurring. The presence of doped holes induces a distribution of displacements of the apex oxygen off of the vertical La-Cu bond axis. These vary from zero to the value observed in lightly doped (antiferromagnetic) La{sub 2}CuO{sub 4+{delta}}. These measurements demonstrate a striking degree of inhomogeneity in the crystal structure of the La-O layer. Copper NQR spectroscopy shows that there are two distinct copper sites in the CuO{sub 2} planes and thus that either the structure or the charge distribution in the planes is inhomogeneous as well. These inhomogeneities are the intrinsic response of the crystal to doped holes; they are not the result of distortions of the lattice due to the presence of interstitial oxygen atoms.

Programs to develop solid core nuclear thermal propulsion (NTP) systems have been under way at the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA), and the Department of Energy (DOE). These programs have recognized the need for a new ground test facility to support development of NTP systems. However, the different military and civilian applications have led to different ground test facility requirements. The Department of Energy (DOE) in its role as landlord and operator of the proposed research reactor test facilities has initiated an effort to explore opportunities for a common ground test facility to meet both DoD and NASA needs. The baseline design and operating limits of the proposed DoD NTP ground test facility are described. The NASA ground test facility requirements are reviewed and their potential impact on the DoD facility baseline is discussed.

In this note the authors describe the results of some tests of the message-passing performance of the Intel Paragon. These tests have been carried out under both the Intel-supplied OSF/1 operating system with an NX library, and also under an operating system called SUNMOS (Sandia UNM Operating System). For comparison with the previous generation of Intel machines, they have also included the results on the Intel Touchstone Delta. The source code used for these tests is identical for all systems. As a result of these tests, the authors can conclude that SUNMOS demonstrates that the Intel Paragon hardware is capable of very high bandwidth communication, and that the message coprocessor on Paragon nodes can be used to give quite respectable latencies. Further tuning can be expected to yield even better performance.

This paper briefly describes an ongoing project designed to assess the uncertainty in offsite radiological consequence calculations of hypothetical accidents in commercial nuclear power plants. This project is supported jointly by the Commission of European Communities (CEC) and the US Nuclear Regulatory Commission (USNRC). Both commissions have expressed an interest in assessing the uncertainty in consequence calculations used for risk assessments and regulatory purposes.

This paper presents a prototype system developed at Sandia National Laboratories to create and verify computer-generated graphical models of remote physical environments. The goal of the system is to create an interface between an operator and a computer vision system so that graphical models can be created interactively. Virtual reality and telepresence are used to allow interaction between the operator, computer, and remote environment. A stereo view of the remote environment is produced by two CCD cameras. The cameras are mounted on a three degree-of-freedom platform which is slaved to a mechanically-tracked, stereoscopic viewing device. This gives the operator a sense of immersion in the physical environment. The stereo video is enhanced by overlaying the graphical model onto it. Overlay of the graphical model onto the stereo video allows visual verification of graphical models. Creation of a graphical model is accomplished by allowing the operator to assist the computer in modeling. The operator controls a 3-D cursor to mark objects to be modeled. The computer then automatically extracts positional and geometric information about the object and creates the graphical model.

The fields of reliability analysis and risk assessment have grown dramatically since the 1970s. There are now bodies of literature and standard practices which cover quantitative aspects of system analysis such as failure rate and repair models, fault and event tree generation, minimal cut sets, classical and Bayesian analysis of reliability, component and system testing techniques, decomposition methods, etc. In spite of the growth in the sophistication of reliability models, however, little has been done to integrate optimization models within a reliability analysis framework. That is, often reliability models focus on characterization of system structure in terms of topology and failure/availability characteristics of components. A number of approaches have been proposed to help identify the components of a system that have the largest influence on overall system reliability. While this may help rank order the components, it does not necessarily help a system design team identify which components they should improve to optimize overall reliability (it may be cheaper and more effective to focus on improving two or three components of smaller importance than one component of larger importance). In this paper, we present an optimization model that identifies the components to be improved to maximize the increase in system MTBF, subject to a fixed budget constraint. A dual formulation of the model is to minimize cost, subject to achieving a certain level of system reliability.

In the detailed phenomenological event trees used in recent Level III PRA analyses questions arise about the possible outcomes of events for which the underlying physics is not well understood and where the initial and boundary conditions are uncertain. Examples of the types of events being analyzed are: What is the containment failure mode?, Is them a large in-vessel steam explosion?, How much H{sub 2}, CO, and CO{sub 2} are produced during core-concrete interactions? The outcomes of each of these questions must be defined based on an understanding of the basic physics of the phenomena and the level of detail of the probabilistic analysis. Many of these phenomena have never occurred since severe reactor accidents are extremely rare events. The only information we have about these phenomena comes from four basic sources: general theoretical knowledge, limited experimental results a few actual events, and various models of the phenomena. All of these phenomena have significant uncertainty arising from three basic sources: level of detail, initial and boundary conditions, and lack of knowledge. Since it is not possible to conduct enough full scale tests to generate a set of ``objective`` relative frequencies, the probabilities, therefore, will have to be ``subjective`` and generated based on expert knowledge. In assessing the conditional probabilities of the various possible outcomes of an event during an accident, the expert must amalgamate his knowledge with the level of detail being used in the PRA analysis to generate a set of probabilities for the defined set of outcomes. It is often convenient for an expert to formulate his opinion in terms of expecting to see n{sub i} occurrences of outcome E{sub i} in N occurrences of event E. The order of the outcomes is typically not important because the individual trials are viewed as being independent of one another.

In many science and engineering applications, there is an interest in predicting the outputs of a process for given levels of inputs. In order to develop a model, one could run the process (or a simulation of the process) at a number of points (a point would be one run at one set of possible input values) and observe the values of the outputs at those points. There observations can be used to predict the values of the outputs for other values of the inputs. Since the outputs are a function of the inputs, we can generate a surface in the space of possible inputs and outputs. This surface is called a response surface. In some cases, collecting data needed to generate a response surface can e very expensive. Thus, in these cases, there is a powerful incentive to minimize the sample size while building better response surfaces. One such case is the semiconductor equipment manufacturing industry. Semiconductor manufacturing equipment is complex and expensive. Depending upon the type of equipment, the number of control parameters may range from 10 to 30 with perhaps 5 to 10 being important. Since a single run can cost hundreds or thousands of dollars, it is very important to have efficient methods for building response surfaces. A current approach to this problem is to do the experiment in two stages. First, a traditional design (such as fractional factorial) is used to screen variables. After deciding which variables are significant, additional runs of the experiment are conducted. The original runs and the new runs are used to build a model with the significant variables. However, the original (screening) runs are not as helpful for building the model as some other points might have been. This paper presents a point selection scheme that is more efficient than traditional designs.

This document is a compilation of various presentations from the Fourth DOE Industry/University/Lab Forum on Robotics for Environmental Restoration and Waste Management held in Albuquerque, New Mexico July 19--21, 1993. Separate abstracts were prepared for each presentation of this report.

A new version of the MACCS code (version 1.5.11.1) has been developed by Sandia National Laboratories under sponsorship of the US Nuclear Regulatory Commission. MACCS was developed to support evaluations of the off-site consequences from hypothetical severe accidents at commercial power plants. MACCS is the only current public domain code in the US that embodies all of the following modeling capabilities: (1) weather sampling using a year of recorded weather data; (2) mitigative actions such as evacuation, sheltering, relocation, decontamination, and interdiction; (3) economic costs of mitigative actions; (4) cloudshine, groundshine, and inhalation pathways as well as food and water ingestion; (5) calculation of both individual and societal doses to various organs; and (6) calculation of both acute (nonstochastic) and latent (stochastic) health effects and risks of health effects. All of the consequence measures may be fun generated in the form of a complementary cumulative distribution function (CCDF). The current version implements a revised cancer model consistent with recent reports such as BEIR V and ICRP 60. In addition, a number of error corrections and portability enhancements have been implemented. This report describes only the changes made in creating the new version. Users of the code will need to obtain the code`s original documentation, NUREG/CR-4691.

This manual describes the procedures and components necessary to produce a holographic interferogram of a flow field in the Sandia National Laboratories hypersonic wind tunnel. In contrast to classical interferometry, holographic interferometry records the amplitude and phase distribution of a lightwave passing through the flow field at some instant of time. This information can then be reconstructed outside the wind tunnel for visual analysis and digital processing, yielding precise characterizations of aerodynamic phenomena. The reconstruction and subsequent hologram image storage process is discussed, with particular attention paid to the digital image processor and the data reduction technique.

This document defines the technical requirements for a test program designed to measure time-dependent concentrations of actinide elements from contact-handled transuranic (CH TRU) waste immersed in brines similar to those found in the underground workings of the Waste Isolation Pilot Plant (WIPP). This test program wig determine the influences of TRU waste constituents on the concentrations of dissolved and suspended actinides relevant to the performance of the WIPP. These influences (which include pH, Eh, complexing agents, sorbent phases, and colloidal particles) can affect solubilities and colloidal mobilization of actinides. The test concept involves fully inundating several TRU waste types with simulated WIPP brines in sealed containers and monitoring the concentrations of actinide species in the leachate as a function of time. The results from this program will be used to test numeric models of actinide concentrations derived from laboratory studies. The model is required for WIPP performance assessment with respect to the Environmental Protection Agency`s 40 CFR Part 191B.

This report describes the requirements, designs, performance, and development histories for the T1576 power supply and the MC3935 rechargeable battery. These devices are used to power Permissive Action Link (PAL) ground controllers. The T1576 consists of a stainless steel container, one SA3553 connector, and one MC3935 battery. The MC3935 is a vented nickel/cadmium battery with 24 cells connected in series. It was designed to deliver 5.5 Amp-hours at 25{number_sign}C and the one-hour rate, with a nominal voltage of 28 V. The battery was designed to operate for 5 years or 500 full charge/discharge cycles. The power supply is expected to last indefinitely with replacement batteries and hardware.

MELCOR is a fully integrated, engineering-level computer code, being developed at Sandia National Laboratories for the USNRC, that models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRS. As part of an ongoing assessment program, the MELCOR computer code has been used to analyze several of the IET direct containment heating experiments done at 1:10 linear scale in the Surtsey test facility at Sandia and at 1:40 linear scale in the corium-water thermal interactions (CWTI) COREXIT test facility at Argonne National Laboratory. These MELCOR calculations were done as an open post-test study, with both the experimental data and CONTAIN results available to guide the selection of code input. Basecase MELCOR results are compared to test data in order to evaluate the new HPME DCH model recently added in MELCOR version 1.8.2. The effect of various user-input parameters in the HPME model, which define both the initial debris source and the subsequent debris interaction, were investigated in sensitivity studies. In addition, several other non-default input modelling changes involving other MELCOR code packages were required in our IET assessment analyses in order to reproduce the observed experiment behavior. Several calculations were done to identify whether any numeric effects exist in our DCH IET assessment analyses.

The LIFE2 computer code is a fatigue/fracture analysis code that is specialized to the analysis of wind turbine components. The numerical formulation of the code uses a series of cycle count matrices to describe the cyclic stress states imposed upon the turbine. However, many structural analysis techniques yield frequency-domain stress spectra and a large body of experimental loads (stress) data is reported in the frequency domain. To permit the analysis of this class of data, a Fourier analysis is used to transform a frequency-domain spectrum to an equivalent time series suitable for rainflow counting by other modules in the code. This paper describes the algorithms incorporated into the code and their numerical implementation. Example problems are used to illustrate typical inputs and outputs.

MELCOR is a fully integrated, engineering-level computer code being developed at Sandia National Laboratories for the USNRC, that models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRs. As a part of an ongoing assessment, program, MELCOR has been used to model the ACRR in-pile DF-4 Damaged Fuel experiment. DF-4 provided data for early phase melt progression in BWR fuel assemblies, particularly for phenomena associated with eutectic interactions in the BWR control blade and zircaloy oxidation in the canister and cladding. MELCOR provided good agreement with experimental data in the key areas of eutectic material behavior and canister and cladding oxidation. Several shortcomings associated with the MELCOR modeling of BWR geometries were found and corrected. Twenty-five sensitivity studies were performed on COR, HS and CVH parameters. These studies showed that the new MELCOR eutectics model played an important role in predicting control blade behavior. These studies revealed slight time step dependence and no machine dependencies. Comparisons made with the results from four best-estimate codes showed that MELCOR did as well as these codes in matching DF-4 experimental data.

Modern nuclear safety themes depend on excluding unwanted energy from the components required for nuclear detonation. The exclusion region barrier is designed to provide protection from extraneous energy. The barrier must remain unbreached for both normal operations and accident events. Recent advances in computational capabilities permits more accurate modeling of barrier tearing during the extreme mechanical loadings associated with accidents. This report describes a methodology which employs design of experiments strategies coupled with finite element analyses and testing to produce results suitable for inclusion in a guide to design exclusion region barriers. The general approach was to employ finite element analyses to define the effect of materials property and geometric feature parameters on a generic barrier geometry. These parametric studies were based on design of experiments strategies. Four materials properties and six geometric features were included in the parameters. Selected geometries were tested to provide verification of the analyses. Statistical analysis of the results from the finite element analyses identified the important parameters (primarily the material property, true strain-to-failure, along with certain geometric characteristics) which were used to synthesize simplified equations and graphics suitable for inclusion into a guide for designers and safety analysts.

Experiments were done to determine effect of lattice damage on solubility and transport of deuterium (D) in silicon carbide. Beta SiC samples were irradiated with energetic ions to produce lattice damage, and were then soaked in D{sub 2} gas at 1000C. Concentration of D versus depth was then measured by nuclear reaction analysis. Very near the surface (<0.5{mu}m), concentration of D was larger in irradiated than in unirradiated, but beyond 1 {mu}m the D concentrations were similar ({approximately}20{plus_minus}10 atomic ppM), even though the damage extended to 2.2 {mu}m in most of the samples. Results from this study of ion-irradiated SiC together with our previous study of tritium migration in undamaged SiC point to the conclusion that uptake of D from gas into SiC occurs by transport along grain boundaries, whereas uptake of D into lattice damage produced by ion irradiation, and release of energetically implanted D both require permeation of D within grains which is much slower.

This report presents equations and computational algorithms for analyzing reliability of several forms of redundancy in repairable and non-repairable systems. For repairable systems, active, standby, and R of N redundancy with and without repair are treated. For non-repairable systems, active, standby, and R of N redundancy are addressed. These equations can be used to calculate mean time between failures, mean time to repair, and reliability for complex systems involving redundancy.

An eXplosive CHEMical kinetics code, XCHEM, has been developed to solve the reactive diffusion equations associated with thermal ignition of energetic materials. This method-of-lines code uses stiff numerical methods and adaptive meshing to resolve relevant combustion physics. Solution accuracy is maintained between multilayered materials consisting of blends of reactive components and/or inert materials. Phase change and variable properties are included in one-dimensional slab, cylindrical and spherical geometries. Temperature-dependent thermal properties have been incorporated and the modification of thermal conductivities to include decomposition effects are estimated using solid/gas volume fractions determined by species fractions. Gas transport properties, including high pressure corrections, have also been included. Time varying temperature, heat flux, convective and thermal radiation boundary conditions, and layer to layer contact resistances have also been implemented.

This report presents a five year plan for the laboratory. This plan takes advantage of the technical strengths of the lab and its staff to address issues of concern to the nation on a scope much broader than Sandia`s original mission, while maintaining the general integrity of the laboratory. The plan proposes initiatives in a number of technologies which overlap the needs of its customers and the strengths of its staff. They include: advanced manufacturing technology; electronics; information and computational technology; transportation energy technology and infrastructure; environmental technology; energy research and technology development; biomedical systems engineering; and post-cold war defense imperatives.

This report provides the results and analyses of a detailed survey undertaken in Summer 1993 to address integrated intrusion detection alarm annunciation and entry control system issues. This survey was undertaken as a first attempt toward beginning to answer questions about integrated systems and commercial capabilities to meet or partially meet US Department of Energy (DOE) site needs.

Hanford`s underground storage tanks (USTs) pose one of the most challenging hazardous and radioactive waste problems for the Department of Energy (DOE). Numerous schemes have been proposed for removing the waste from the USTs, but the technology options for doing this are largely unproven. To help assess the options, an Independent Review Group (IRG) was established to conduct a broad review of retrieval systems and the tank waste remediation system. The IRG consisted of the authors of this report. The IRG`s Preliminary Report assessed retrieval systems for underground storage tank wastes at Hanford in 1992. Westinghouse Hanford Company (WHC) concurred with the report`s recommendation that a tool should be developed for evaluating retrieval concepts. The report recommended that this tool include (1) important considerations identified previously by the IRG, (2) a means of documenting important decisions concerning retrieval systems, and (3) a focus on evaluations and assessments for the Tank Waste Remediation System (TWRS) and the Underground Storage Tank-Integrated Demonstration (UST-ID).

This document presents the objectives, accomplishments and activity plan for the Sandia Wind Energy Technology Program. The status of the current program is summarized and the planned FY94 activities are defined. Appendices detailing the cost, performance and schedule associated with these activities are also included. Funding requirements are given for several scenarios in order to reflect the impact of funding variability on program progress.

The Sandia National Laboratories, New Mexico (SNL/NM) Site-Wide Hydrogeologic Characterization (SWHC) project has been implemented as part of the SNL/NM Environmental Restoration (ER) Program to develop the regional hydrogeologic framework and baseline for the approximately 100 mi of Kirtland Air Force Base (KAFB) and adjacent withdrawn public lands upon which SNL/NM has performed research and development activities. Additionally, the SWHC project will investigate and characterize generic hydrogeologic issues associated with the 172 ER sites owned by SNL/NM across its facilities on KAFB. As called for in the Hazardous and Solid Waste Amendments (HSWA) to the Resource Conservation and Recovery Act (RCRA) Part B permit agreement between the U.S. Environmental Protection Agency (EPA) as the permitter and the U.S. Department of Energy (DOE) and SNL/NM as the permittees, an annual report is to be prepared by the SWHC project team. This document serves two primary purposes: (1) to identify and describe the conceptual framework for the hydrogeologic system underlying SNL/NM and (2) to describe characterization activities undertaken in the preceding year that add to our understanding (reduce our uncertainties) regarding the conceptual and quantitative hydrogeologic framework. This SWHC project annual report focuses primarily on purpose 1, providing a summary description of the current {open_quotes}state of knowledge{close_quotes} of the Sandia National Laboratories/Kirtland Air Force Base (SNL/KAFB) hydrogeologic setting.

Small-polarons will only form in covalent crystals whose electronic halfbandwidths are sufficiently narrow, E{sub b} > W. The absence of small polaronic carriers in most covalent crystals presumably indicates that E{sub b} < W in these instances. However, evidence of small polarons is commonly found in disordered materials despite the estimates of E{sub b} and W not being significantly different from those of crystals. This result is ration by stating that disorder has slowed carrier motion enough to permit small-polaron formation. Recently the question of how disorder affects the stability of quasifree carriers with respect to small-polaron formation has been addressed. It is found that only modest energetic disorder is required to induce small-polaron formation. Here I first succinctly describe essential elements of this work. Second, I address the role of disorder on the adiabatic hopping motion of small polarons. Energy bands in most materials in which small-polarons are found are thought to be sufficiently wide (> a phonon energy) that the small-polaronic hopping is ``adiabatic.`` That is, the electronic carriers move between sites sufficienfly rapidly to follow the atomic motions. In this situation the small-polaron jump rates are independent of intersite separations. The magnitudes of the preexponential factors of the measured hopping mobilities typically support this view. Further support for this picture is found from experiments that determine weak dependences of the mobility on hydrostatic pressure.

The introduction of rapid prototyping machines into the marketplace promises to revolutionize the process of producing prototype parts with production-like quality. In the age of concurrent engineering and agile manufacturing, it is necessary to exploit applicable new technologies as soon as they become available. The driving force behind integrating these evolutionary processes into the design and manufacture of prototype parts is the need to reduce lead times and fabrication costs, improve efficiency, and increase flexibility without sacrificing quality. Sandia utilizes Stereolithography (SL) and Selective Laser Sintering (SLS) capabilities to support internal design and manufacturing efforts. SL is used in the design iteration process to produce proof-of-concept models, hands-on models for design reviews, fit-check models, visual aids for manufacturing, and functional parts in assemblies. SLS is used to produce wax patterns for the lost wax process of investment casting in support of an internal Sandia National Laboratories program called FASTCAST which integrates experimental and computational technologies into the investment casting process. This presentation will provide a brief overview of the SL and SLS processes and address our experiences with these technologies from the standpoints of application, accuracy, surface finish, and feature definition. Also presented will be several examples of prototype parts manufactured by the Stereolithography and Selective Laser Sintering rapid prototyping machines.

Technical advances in lead-acid battery design have created new opportunities for battery systems in telecommunications, computer backup power and vehicle propulsion power. Now the lead-acid battery has the opportunity to become a major element in the mix of technologies used by electric utilities for several power quality and energy and resource management functions within the network. Since their introduction into industrial applications, Valve Regulated Lead-Acid (VRLA) batteries have received widespread acceptance and use in critical telecommunications and computer installations, and have developed over 10 years of reliable operational history. As further enhancements in performance, reliability and manufacturing processes are made, these VRLA batteries are expanding the role of battery-based energy storage systems within utility companies portfolios. This paper discusses the rationale and process of designing, optimizing and testing VRLA batteries for specific utility application requirements.

This paper describes an approach to developing a business plan which also serves as a quality plan and quality manual. It is organized following the major categories of the Malcolm Baldrige National Quality Award. It has been applied to the Measurement Standards Program Operations at Sandia National Laboratories.

Sandia National Laboratories (SNL) is engaged actively in research to improve the ability to accurately predict the response of engineered systems to thermal and structural abnormal environments. Abnormal environments that will be addressed in this paper include: fire, impact, and puncture by probes and fragments, as well as a combination of all of the above. Historically, SNL has demonstrated the survivability of engineered systems to abnormal environments using a balanced approach between numerical simulation and testing. It is necessary to determine the response of engineered systems in two cases: (1) to satisfy regulatory specifications, and (2) to enable quantification of a probabilistic risk assessment (PRA). In a regulatory case, numerical simulation of system response is generally used to guide the system design such that the system will respond satisfactorily to the specified regulatory abnormal environment. Testing is conducted at the regulatory abnormal environment to ensure compliance.

A wide variety of space-based system components have been qualified for use through neutron irradiation testing performed at the Sandia Pulsed Reactor (SPR) Facility. The SPR Facility is the operating location for two fast burst reactors, SPR II and SPR III, which have been used to induce neutron and gamma damage in electronic components and other materials for customers in the Department of Energy, Department of Defense, NASA,, and the private sector. In addition to the pulse mode of operation, during which peak fluxes of up to lel9 n/cm{sup 2}{minus}s are achieved, the steady state mode allows for the long term irradiation of components and systems in a fast neutron environment at a flux of up to 5e11 n/cm{sup 2}{minus}s. The SPR reactors are operated in a 9.2 meter diameter exposure cell, or Kiva, suitable for the irradiation of large test articles external to the reactors. Currently, a new upgraded version of SPR Ill (SPR IIIM) is in fabrication; a unique feature of SPR IIIM is its 19 cm (usable diameter) central irradiation cavity, the largest of any US fast burst reactor. An improved cooling system permits continuous operation at power levels in excess of 20 kW{sub t}. The SPR Facility is also the operating site for a critical assembly which was used to characterize prototypic fuels in arrays appropriate for the Space Nuclear Thermal Propulsion Program. Work continues on use of the facility to design, build, and operate critical assemblies for a diverse customer base.

The present political and environmental climate may slow the inevitable direct utilization of nuclear power in space. In the meantime, there is another approach for using nuclear energy for space power. That approach is to let nuclear energy generate a laser beam in a ground-based nuclear reactor-pumped laser (RPL), and then beam the optical energy into space. Potential space applications for a ground-based RPL include (1) illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, (2) beaming power to orbital transfer vehicles, (3) providing power (from earth) to a lunar base during the long lunar night, and (4) removing space debris. FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy with Sandia National Laboratories as the lead laboratory. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 0.585, 0.703, 0.725, 1.271, 1.733, 1.792, 2.032, 2.63, 2.65, and 3.37 {mu}m with intrinsic efficiency as high as 2.5%. Frequency-doubling the 1.733{minus}{mu}m line would yield a good match for photovoltaic arrays at 0.867 {mu}m. Preliminary designs of an RPL suitable for power beaming have been completed. The MWclass laser is fairly simple in construction, self-powered, closed-cycle (no exhaust gases), and modular. This paper describes the FALCON program accomplishments and power-beaming applications.

The production, suspension and transport of fluorocarbon particulates in rf discharges have been studied using in situ laser light scattering and ex situ chemical analysis. The time evolution of the spatial distribution of suspended particles was obtained by 2-D imaging of the scattered light. The chemistry of the discharge was varied by the use of a range of pure fluorocarbon gases and mixtures with argon, oxygen and hydrogen-containing molecules. The addition of hydrogen to a fluorocarbon discharge increases the rate of formation of particles although these powders are found by FTIR to contain negligible hydrogen. Particle formation rates correlate with polymer deposition rates and are independent of apparatus history. It is proposed that this is a clear example of gas-phase rather than surface processes leading to particle nucleation and growth.

The government electronics community faces the exciting challenge of entering into new of types of partnerships with the commercial electronics industry. Past interactions have been based primarily on the needs of government. Future interactions will be based more on the needs of industry, particularly its need to be competitive in commercial products. The most successful groups will be those most adept at forming this new type of ``win-win`` partner. Fortunately, both government and industry want to make these new partnerships successful. The government is driven by the necessity of establishing a common government/commercial manufacturing base and the desire to support US competitiveness. Industry is driven by the need to partner with government to remain competitive. Unfortunately, there are no detailed guides available to help government electronics groups and their sponsors in the Administration and Congress cross this uncharted terrain. The purpose of this paper is to share some ``lessons learned`` from the experiences of a government electronics group that has been active in establishing these new types of partnerships with industry. It is our hope that by sharing these lessons we will make it easier for other government groups to work with the commercial industry.

The author proposes using the collective Thomson scattering lineshape from ion acoustic waves to measure the spatial structure of local heat transport parameters and collisionality. Ion acoustic peak height asymmetry is used in conjunction with a recently developed model describing the effects of collisional and Landau damping contributions on the low-frequency electron density fluctuation spectrum to extract the relative electron drift. The local heat flux q{sub e} (proportional to drift) and the electron thermal conductivity {kappa}{sub e}{minus}q{sub e}/{gradient}T{sub e} would be inferred from experimentally determined temperature gradients {gradient}T{sub e}. Damping of the entropy wave component at zero mode frequency is shown to be an estimate of the ion thermal conductivity {kappa}{sub i}, and its visibility is a direct measure of the ion-ion mean free path {lambda}{sub ii}.

Sandia National Laboratories (SNL) is actively engaged in research to characterize abnormal environments, and to improve our capability to accurately predict the response of engineered systems to thermal and structural events. Abnormal environments, such as impact and fire, are complex and highly nonlinear phenomena which are difficult to model by computer simulation. Validation of computer results with full scale, high fidelity test data is required. The number of possible abnormal environments and the range of initial conditions are very large. Because full-scale tests are very costly, only a minimal number have been conducted. Scale model tests are often performed to span the range of abnormal environments and initial conditions unobtainable by full-scale testing. This paper will discuss testing capabilities at SNL, issues associated with thermal and structural scaling, and issues associated with extrapolating scale model data to full-scale system response. Situated a few minutes from Albuquerque, New Mexico, are the unique test facilities of Sandia National Laboratories. The testing complex is comprised of over 40 facilities which occupy over 40 square miles. Many of the facilities have been designed and built by SNL to simulate complex problems encountered in engineering analysis and design. The facilities can provide response measurements, under closely controlled conditions, to both verify mathematical models of engineered systems and satisfy design specifications.

Over the past 40 years, Sandia National Laboratories (SNL) has been actively engaged in research to improve the ability to accurately predict the response of engineered systems to abnormal thermal and structural environments. These engineered systems contain very hazardous materials. Assessing the degree of safety/risk afforded the public and environment by these engineered systems, therefore, is of upmost importance. The ability to accurately predict the response of these systems to accidents (to abnormal environments) is required to assess the degree of safety. Before the effect of the abnormal environment on these systems can be determined, it is necessary to ascertain the nature of the environment. Ascertaining the nature of the environment, in turn, requires the ability to physically characterize and numerically simulate the abnormal environment. Historically, SNL has demonstrated the level of safety provided by these engineered systems by either of two approaches: (1) a purely regulatory approach, or (2) by a Probabilistic Risk Assessment (PRA). This paper will address the latter of the two approaches.

We have found that aluminum alloys exhibit unusual passivity when exposed to alkaline Li-salt solutions. Observed passivity is due to the formation of a polycrystalline Li{sub 2}[Al{sub 2}(OH){sub 6}]{sub 2}{center_dot}CO{sub 3}{center_dot}3H{sub 2}O film on the aluminum surface. This film is persistent in aggressive environments and provides a significant degree of corrosion protection. On this basis, we have developed a simple non-electrolytic method of forming corrosion resistant coatings in alkaline Li-salt solution. This process is procedurally similar to traditional conversion coating methods, offers desirable properties, and has a low toxic hazard. In this paper, coating methods, coating characterization, and coating properties are presented. Results from parallel test performed with a commercial chromate conversion coatings are presented for comparison.

This report discusses fourteen tests which were conducted to investigate the perforation of thin unreinforced concrete slabs. The 4340-steel projectile used in the test series is 50.8 mm in diameter, 355.6 mm in length, has a mass of 2.34 kg. and an ogive nose with caliber radius head of 3. The slabs, contained within steel culverts, are 1.52 m in diameter and consist of concrete with a nominal unconfined compressive strength of 38.2 MPa and maxima aggregate size of 9.5 mm. Slab thicknesses are 284.4, 254.0, 215.9 and 127.0 mm. Tests were conducted at impact velocities of about 313 m/s on all slab thicknesses and about 379 and 471 m/s on the 254.0-mm-thick slab. All tests were conducted at normal incidence to the slab. All tests were conducted at normal incidence to the slab. Information obtained from the tests used to determine the loading (deceleration) on the projectile during the perforation process, the velocity-displacement of the projectile as it perforated the slab, and the projectile position as damage occurred on the backface of the slab. The test projectile behaved essentially as a rigid body for all of the tests.

Sandia`s gas sensor program encompasses three separate electronic platforms: Acoustic Wave Devices, Fiber Optic Sensors and sensors based on silicon microelectronic devices. A review of most of these activities was presented recently in a article in Science under the title ``Chemical Microsensors.`` The focus of the program has been on understanding and developing the chemical sensor coatings that are necessary for using these electronic platforms as effective chemical sensors.