Publications

Sandia National Laboratories has developed a variety of alarm communication and display systems for a broad spectrum of users. This paper will briefly describe the latest systems developed for the Department of Energy (DOE), the Department of Defense (DoD), and the Department of State (DOS) applications. Applications covered will vary from relatively small facilities to large complex sites. Ongoing system developments will also be discussed. The concluding section will summarize the practical, implementable state-of-the-art features available in new systems. 6 figs.

The mechanical behavior of microcellular open-cell foams prepared by a thermally induced phase separation process are investigated. The foams studied were prepared from isotactic polystyrene, polyacrylonitrile, and poly(4-methyl-1-pentene) (rigid foams), and polyurethane and Lycra (elastomeric foams). Their densities were in the range 0.04--0.27 g/cm3. Conventional polystyrene foams were used for comparison. The moduli and collapse stresses of these foams were measured in compression and compared with the current constitutive laws which relate mechanical properties to densities. A reinforcement technique based on the in-situ precipitation of silica was used to improve the mechanical properties. 13 refs., 4 figs., 3 tabs.

Ion implantation has been shown to produce unique improvements in the properties of a wide range of materials. This technology has been extensively used for doping of semiconductors, where the required doses and implantation depths are relatively modest and readily achieved with commercial implanters. Other applications of ion implantation currently being pursued at a commercial level include the synthesis of buried second-phase layers in Si and the improvement of metal surface properties such as hardness, friction, wear rate, and corrosion. However, these applications have been severely constrained by the costs of treating large surface areas with the high ion doses required, and by the need to produce modified layers thicker than the range of the sub-MeV ions available from presently available commercial high-flux ion implanters. It therefore seems worthwhile to consider whether pulsed ion accelerators may offer advantages for such applications by providing high ion fluxes at MeV energies. The previously reported applications of pulsed accelerators to materials modification have used sub-MeV ion energies. The purpose of this article is to being these considerations the perspective of materials scientists who use ion implantation. We comment on needed extensions in implantation capabilities while leaving to others the question of whether these needs can be met with pulsed-beam technology. Further, in order to illustrate the kinds of beneficial materials modifications that can be achieved with implantation, we provide examples from recent work at Sandia National Laboratories, where large improvements have been realized in the tribological properties and strengths of Fe and A{ell} alloys. 10 refs., 6 figs.

The natural language technique was just one of many approaches to information system design in 1987. The success of this approach convinced management of the viability of this new'' approach. A group was created to use natural language in information system specifications and designs. Two of the projects undertaken by this group will be reviewed. The first is a quality database that allows for the management of the process that certifies production capabilities for major weapon components and the second tracks command and control status of weapons. A third external project involving nuclear disarmament will also be discussed.

The United States Department of Energy (DOE) plans to use the Waste Isolation Pilot plant (WIPP) in southeastern New Mexico for disposal of transuranic wastes generated by defense programs. The DOE must first demonstrate compliance with the Environmental Protection Agency's (EPA) Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR Part 191) hereafter called the Standard. The Standard was vacated by a Federal Court of Appeals in 1987 and is undergoing revision; by agreement with the State of New Mexico the DOE will continue to evaluate repository performance with respect to the Standard as first promulgated until a new version is available. This paper reviews the results of a 1989 preliminary demonstration of the performance-assessment methodology that will be used by the WIPP project ultimately to assess compliance with the Standard. The report also describes conceptual and numerical improvements in the performance-assessment methodology made during 1990, and summarizes the progress made toward achieving the probabilistic assessment of repository performance required for regulatory compliance. 13 refs., 4 figs.

Low-density, microcellular polymer foams have numerous applications as structural supports in high-energy physics experiments, in catalysis, ion exchange, and filtration, and for a variety of biomedical uses. A versatile method to prepare such foams is by thermally-induced phase separation (TIPS) of polymer solutions. Demixed solutions can be transformed into a foam by freezing the demixed solution and removing the solvent by freeze-drying. The morphology of these foams is determined by the the thermodynamics and kinetics of phase separation. A model of both the early and late stage structure development for demixed polymer solutions will be presented. For semi-crystalline polymers, gels can be prepared by crystallizing the polymer from solution, either a homogeneous solution or a demixed solution. Foams can be prepared from these gels by the supercritical extraction of the solvent. By understanding and utilizing the phase separation behavior of polymer solutions, engineered microcellular foams can be prepared. To design the foams for any application one must be able to characterize their morphology. Results will be presented on the morphological characterization of these foams and the relationship of the morphology to their processing history. 14 refs., 12 figs.

Infrared absorption and photoluminescence have been demonstrated for InAs{sub 1-x}Sb{sub x}/InSb strained-layer superlattices (SLS's) in the 8--15 {eta}m region for As content less than 20%. This extended infrared activity is due to the type II heterojunction band offset in these SLS's. The preparation of the first MOCVD grown p-n junction diode was achieved by using dimethyltellurium as an in-type dopant. Several factors, such as background doping and dopant profiles affect the performance of this device. InSb diodes have been prepared using tetraethyltin. The resulting current-voltage characteristics are improved over those of diodes grown previously using dimethyltellurium. Doping levels of 8 {times} 10{sup 15} to 5 {times} 10{sup 18} cm{sup {minus}3} and mobilities of 6.7 {times} 10{sup 4} to 1.1 {times} 10{sup 4} cm{sup 2}/Vs have been measured for Sn doped InSb. SLS diode structures have been prepared using Sn and Cd as the dopants. Structures prepared with p-type buffer layers are more reproducible. 5 refs., 4 figs.

This paper describes the analysis of the Three Mile Island-2 (TMI-2) standard problem that was performed with MELCOR. The MELCOR computer code is being developed by Sandia National Laboratories for the Nuclear Regulatory Commission for the purpose of analyzing severe accident in nuclear power plants. The primary role of MELCOR is to provide realistic predictions of severe accident phenomena and the radiological source team. The analysis of the TMI-2 standard problem allowed for comparison of the model predictions in MELCOR to plant data and to the results of more mechanistic analyses. This exercise was, therefore valuable for verifying and assessing the models in the code. The major trends in the TMI-2 accident are reasonably well predicted with MELCOR, even with its simplified modeling. Comparison of the calculated and measured results is presented and, based on this comparison, conclusions can be drawn concerning the applicability of MELCOR to severe accident analysis. 5 refs., 10 figs., 3 tabs.

Steady state roughness of surfaces growing by molecular beam epitaxy is investigated by Monte Carlo simulations under conditions where an ion beam is also present which sputters adatoms off the surface. If the sputtering is random, it only increases the roughness. But if the sputtering probability is strongly dependent on the binding energy of an adatom within a cluster or island, the ions can have a smoothening effect. Physical arguments are given in support of the results. 8 refs., 4 figs.

The purpose of this paper is to discuss the current issues of interest in PV concentrator module reliability. Before describing in detail the reliability concerns about PV concentrator modules, it should be emphasized that, with proper design and attention to quality control, there is nothing to prevent concentrator modules from being as reliable as crystalline-silicon flat-plate modules have proven to be. Concentrator modules tested outdoors, as well as in the first-generation systems, have generally been reliable, and no degradation in cell output has been observed. Also, although they are not included in this paper, there are a few items currently of concern with the reliability of other PV module technologies that are not issues with PV concentrator technology, such as the stability of amorphous-silicon efficiencies and concerns about EVA encapsulation.

The deformation and crack initiation behavior of Ti-24Al-11Nb has been examined over a temperature range of 298 to 923 K and for strain rates from 10{sup {minus}4}/s to 10{sup 2}/s. Tests performed in compression indicate much lower strain hardening at 10{sup 2}/s than at either 10{sup {minus}1}/s or 10{sup {minus}4}/s at all temperatures. Associated with this behavior is the occurrence of non-uniform, localized deformation bands at 10{sup 2}/s. An analysis indicates that adiabatic deformation conditions predominate at 10{sup 2}/s and that these result in adiabatic softening. Furthermore, as a result of non-uniform deformation and adiabatic heating, this Ti{sub 3}-Al-based alloy is actually more resistant to strain-induced microcrack initiation at 10{sup 2}/s than at 10{sup {minus}4}/s during room temperature testing. 16 refs., 7 figs.

This paper attempts to give an elementary review of the kinematics of large deformations with a view to illustrating some of the underlying geometric concepts, and then goes on to review some basic features of elastic, hypoelastic, and rate type constitutive equations relevant to their use in numerical methods. Since some recent work has emphasized working in a rotated'' intermediate configuration, one in which the rigid body rotation has been backed out, results relating to this configuration are included, otherwise all of the results have been read off directly from Truesdell and Toupin ( ) or Truesdell and Noll ( ). Finally, results given by Nemat-Nasser ( ) are quoted which reconcile some generalizations of infinitesimal plasticity and some remarks are made relevant to the introduction of tensor internal state variables. Thermodynamic effects, although important in calculations, are omitted to emphasize kinematical effects. Because recent authors have used different names and symbols for stress and strain tensors, it has been found necessary to give a self contained if abbreviated development of the kinematics, which, however, allows a compact discussion of constitutive equations.

We report formation of several small colloidal metal catatlysts in inverted micelle (oil-continuous) systems. These materials have demonstrated catalytic activity in situ (i.e. unsupported). The range of solvents possible in this process is large, including all saturated hydrocarbons, cyclic hydrocarbons (e.g. cyclohexane) and aromatics (e.g. toluene, xylene). Three classes of micelle system were investigated, nonionic, anionic, and cationic. Nonionic types allow precise size control but in general do not act as strong stabilizing agents at high temperatures. Cationics can be chosen to provide this permanent stability, providing both charge and steric stabilization. Metal systems formed include Rh, Ni, NiB, MoO{sub 2}, Pd, Au and Ag and alloys. Selected examples are given. 4 figs.

This paper presents an analytical and numerical analysis which evaluates the core-structure heat-up and subsequent relocation of molten core materials during a NWR short-term station blackout accident with ADS. A simplified one-dimensional approach coupled with bounding arguments is first presented to establish an estimate of the temperature differences within a BWR assembly at the point when structural material first begins to melt. This analysis leads to the conclusions that the control blade will be the first structure to melt and that at this point in time, overall temperature differences across the canister-blade region will not be more than 200 K. Next, a three-dimensional heat-transfer model of the canister-blade region within the core is presented that uses a diffusion approximation for the radiation heat transfer. This is compared to the one-dimensional analysis to establish its compatibility. Finally, the extension of the three-dimensional model to include melt relocation using a porous media type approximation is described. The results of this analysis suggest that under these conditions significant amounts of material will relocate to the core plate region and refreeze, potentially forming a significant blockage. The results also indicate that a large amount of lateral spreading of the melted blade and canister material into the fuel rod regions will occur during the melt progression process. 22 refs., 18 figs., 1 tab.

Fatigue life estimates for wind turbine components can be extremely variable due to both inherently random and uncertain parameters. A structural reliability analysis is used to qualify the probability that the fatigue life will fall short of a selected target. Reliability analysis also produces measures of the relative importance of the various sources of uncertainty and the sensitivity of the reliability to each input parameter. The process of obtaining reliability estimates is briefly outlined. An example fatigue reliability calculation for a blade joint is formulated; reliability estimates, importance factors, and sensitivities are produced. Guidance in selecting distribution functions for the random variables used to model the random and uncertain parameters is also provided. 5 refs., 9 figs., 1 tab.

Photovoltaic concentrator collectors are an attractive option for utility-scale photovoltaic power plants. This paper reviews the current status of photovoltaic concentrator collector and cell development. Included in the review is a discussion of the economic motivation for concentrators, a summary of recent concentrator collector and cell development, and a description of a major new program to accelerate development and commercial introduction of concentrator collectors. 21 refs., 1 fig., 3 tabs.

Physical security specialists have been attracted to the concept of video motion detection for several years. Claimed potential advantages included additional benefit from existing video surveillance systems, automatic detection, improved performance compared to human observers, and cost effectiveness. In recent years significant advances in image processing dedicated hardware and image analysis algorithms and software have accelerated the successful application of video motion detection systems to a variety of physical security applications. Currently Sandia is developing several advanced systems that employ image processing techniques for a broader set of safeguards and security applications. TCATS (Target Cueing and Tracking System) uses a set of powerful, flexible, modular algorithms and software to alarm on purposeful target motion. Custom TCATS hardware optimized for perimeter security applications is currently being evaluated with video input. VISDTA (Video Imaging System for Detection, Tracking, and Assessment) uses some of the same TCATS algorithms and operates with a thermal imager input. In the scan mode, VISDTA detects changes in a scene from the previous image at a given scan point; in the stare mode, VISDTA detects purposeful motion similar to TCATS.

Many of the properties associated with ceramic materials such as high hardness, high dielectric constant, refractoriness, and good optical properties will play a critical role in the development of devices for new and emerging technologies. In many cases, the combination of properties that is required demands that a composite material be designed to fulfill these complex materials needs. The increasing emphasis upon composite materials design and performance necessarily focuses greater attention upon the structure and properties of interfaces in ceramic materials. One on the most important aspects of interfacial behavior is the adhesive stability. As an example, high hardness ceramic coatings for tribological applications require a high degree of interfacial adhesion with the underlying substate material. Alternatively it has been shown that fiber reinforced ceramic composites that are designed for high fracture toughness must contain weak interfaces that allow for fiber pull-out to toughen the instrinsically brittle ceramic matrix. Our ability to design ceramic interfaces for specific interfacial adhesive behavior dictates that we develop a full understanding of the factors that control the adhesive bond in these systems. We report on the use of continuum fracture mechanics techniques to identify the molecular source of adhesion between oxide surfaces and introduce a new approach to measuring interfacial adhesive forces using an Interfacial Force Microscope.

Although computational aerodynamics simulation has been taking more responsibility during recent years, wind tunnel experimentation has continued to play the major role in flight vehicle analysis and design.This role, however, is changing because of the great strides in the capability and confidence in numerical simulations. For a small, well defined, class of supersonic and hypersonic flow problems, high quality numerical solutions are now believed to represent the physics of the problem more accurately than a wind tunnel experimental can simulate the free flight conditions. An example of this is the supersonic or hypersonic, laminar, perfect gas flow over a spherically blunted cone at low angle of attack. In this paper, aerodynamic force and moment measurements and flow visualization results are presented for a reentry vehicle configuration at Mach 8. All of the results were obtained in the Sandia Mach 8 long duration, blow-down, hypersonic wind tunnel. The basic vehicle configuration is a spherically blunted cone with a slice parallel with the axis of the vehicle. Onto the slice portion of the vehicle can be attached flaps with three different deflection angles, 10, 20 and 30 deg. Flow visualization results include surface oil flow, spark Schlieren, and liquid crystal photographs. 1 ref., 7 figs.

An AlGaAs window layer is used in high-efficiency GaAs solar cells to reduce carrier recombination at the front surface. Free surfaces of III-V semiconductors have a high density of surface states that serve as recombination sites and create a depletion region at the front surface. We have performed a theoretical investigation of front-surface recombination that includes the effect of a surface space-charge layer. It was found that the surface space-charge layer can have a profound effect on front-surface recombination for thin or lightly doped window layers. 15 refs., 5 figs., 1 tab.

Transport by groundwater within the Culebra Dolomite, an aquifer above the Waste Isolation Pilot Plant (WIPP), is the most probable mechanism for long-term release of radionuclides to the accessible environment. Radionuclides could be retarded by sorption if the groundwater is exposed to sufficient amounts of fracture-lining clays. In this natural-analog study, distributions of U and trace metals have been examined to constrain the strength of clay/solute interactions within the Culebra. Uranium solid/liquid distribution ratios, calculated from U concentrations of groundwaters and consanguineous fracture-filling clays, range from {approximately}80 to 800 m{ell}/g and imply retardation factors of 60 to 500 using a fracture-flow model. Retardation factors inferred from uranium-series disequilibria and {sup 14}C ages in Culebra groundwaters alone are much lower ({approximately}10), implying that clays may contain a significant unreactive component of U. Such a possibility is corroborated by Rb/Sr ages; these imply long-term stability of the clays,with resetting occurring more than 250 Ma ago. Factor analysis and mass-balance calculations suggest, however, that Mg-rich clays are dissolving in Pleistocene-age groundwaters and/or are converting to Na-rich smectites, and that B and Li are taken up from the water by the clays. Apparently, the solution chemistry reflects gradual equilibration of clays with groundwater, but thus far the bulk of the clays remain structurally intact. Measurements of the distribution of U in the Culebra will be more meaningful if the inert and exchangeable components of the U content of the clays can be quantified. 26 refs., 3 figs., 2 tabs.

Computer simulation of low-energy ion-solid processes has greatly broadened in scope in recent years. In particular, realistic descriptions of the ion-solid and solid-solid interactions can now be utilized. The molecular dynamics technique, in which the equations of motion of the interacting atoms are numerically integrated, can now be used to characterize ion-solid interactions in a range of model material systems. Despite practical limitations of this procedure, a number of substantial results have appeared. The available results are examined to investigate the qualitative influence that chemical interactions have on low-energy ion-solid processes. 26 refs., 4 figs.

Good quality, low temperature silicon nitride and oxynitride films were deposited downstream from an electron cyclotron resonance (ECR) plasma source using SiH{sub 4} and N{sub 2} gas mixtures. The Si/N ratio and H content in the deposited films were determined using Rutherford backscattering spectrometry (RBS)and elastic recoil detection (ERD). The H concentration was minimum for films with compositions closest to that of stoichiometric Si{sub 3}N{sub 4}. The optimum conditions for producing a stoichiometric Si{sub 3}N{sub 4}were: a SiH{sub 4}/N{sub 2} flow ratio between 0.1 and 0.2, and an electrically isolated sample far from the ECR source. Infrared absorption spectra showed that as the film composition changed from N rich to Si rich the dominant bonds associated with H changed from N-H to Si-H. The addition of O{sub 2} to the background gas formed an oxynitride with a low H content similar to the stoichiometric Si{sub 3}N{sub 4} 10 refs., 4 figs., 2 tabs.

We have used a Tl-Ca-Ba-Cu-O superconducting flux flow transistor (SFFT) as an active impedance converter between Josephson and FET circuitry. The input of the flux flow device is a control line of low impedance that can be driven by a tunnel junction. The output is the signal across the SFFT which is made of a parallel array of weak links. The output impedance is typically greater than 5 {Omega} with a maximum voltage swing of over 100 mV into a 50 {Omega} system. The switching of an all-Nb junction induced a 90 mV voltage swing at the FET input and over 200 mV at the FET output. The line driver can operate anywhere between 4.2K and 85K with minor changes in speed ({plus minus}5 ps) and output level ({plus minus}10 mV). The switching time measured was about 100 ps and was fixture limited. 13 refs., 5 figs.

Archimedes is a prototype mechanical assembly system which generates and executes robot assembly programs from a CAD model input. The system addresses the unrealized potential for flexibility in robotic mechanical assembly applications by automating the programming task. Input is a solid model of the finished assembly. Parts relationships and geometric constraints are deduced from the solid model. A rule-based planner generates a generic'' assembly plan that satisfies the geometric constraints, as well as other constraints embodied in the rules. A retargetable plan compiler converts the generic plan into code specific to an application environment. Execution of the compiled plan in a workcell containing an Adept Two robot, a vision system, and other parts handling equipment will be shown on videotape.

This concept brings a condensed source of tritium into close proximity with an inorganic phosphor. That source may thus become the equivalent of many atmospheres of tritium gas pressure. If both phosphor and tritium source material are optically clear, then a lamp's brightness may be made to scale with optical path length. Proof of principle of this concept has been demonstrated and will be described. A theoretical treatment is presented for the results here and for results from aerogel experiments.

Pressurized water reactor pressure vessels operate under US Nuclear Regulatory Commission (NRC) rules and regulatory guides that are intended to maintain a low probability of vessel failure. The NRC has also addressed neutron embrittlement of pressurized water reactor pressure vessels by imposing regulations on plant operation. Plants failing to meet the operating criteria specified by these rules and regulations are required, among other things, to analytically demonstrate fitness for service in order to continue safe operation. The initial flaw size or distribution of initial vessel flaws is a key input to the required vessel integrity analyses. A fracture mechanics sensitivity study was performed to quantify the effect of the assumed flaw distribution on the predicted vessel performance under a specified pressurized thermal shock transient and to determine the critical crack size. Results of the analysis indicate that vessel performance in terms of the estimated probability of failure is very sensitive to the assumed flaw distribution. 20 refs., 3 figs., 2 tabs.

Short communication.

Inorganic zeolites show promise as an alternative to traditional tritium gas tube light sources. Greater proximity of tritium atoms and luminescing centers, as well as greater tritium loading density, have been obtained within the zeolite aluminosilicate matrix. Zeolites are in addition optically clear and radiation stable. The zeolite radioluminescence program is described. Procedures for obtaining light sources are presented and results are discussed. 12 refs., 1 fig.

The microstructure of Al ion-implanted at room temperature with 17 at. % 0 has been characterized with TEM. The alloy has extremely small (1.5--3.5 nm) oxide precipitates whose crystal structure is interpreted to be a disordered version of {gamma}-Al{sub 2}O{sub 3} having a fcc lattice of O{sup 2{minus}} ions with Al{sup 3+} ions in random interstitial sites. The small sizes can account for the exceptionally high strength of as-implanted alloys: 2500--3300 MPa. Larger precipitates are found when the alloy is annealed 1/2 hour at 550{degree}C, which is consistent with its somewhat lower strength: 800--1600 MPa. 4 figs.

Solderability of Class II environmentally exposed Ni-Sn plated Cu substrates was evaluated with 60Sn-40Pb solder. Tin thickness were 10, 50, and 150 {mu}in. The 10 {mu}in. plating gave the smallest solder meniscus rise. A general decrease in contact angle, or increase in wettability, was observed with increasing Sn plating. The environmental exposures retarded the wetting rate and increased the time to maximum wetting, particularly with only 10 {mu}in. of Sn. Although the solderability of the 50 and 150 {mu}in. surfaces were not significantly affected by the test conditions, an intermediate plating thickness of 100 {mu}in. is preferred for processing flexibility. 13 refs., 6 figs., 1 tab.

SICADS is a generic command, control and display software package which provides the capability to generate security systems which employ different hardware and system configurations, but which are controlled by the same software. SICADS was designed to avoid the task of developing new software for each site. By reusing software, expenses are reduced and software quality is increased. Tested software can be reused without modifications. Configurations of security systems vary from site to site. In many systems, a seemingly minor change in configuration has required significant software modifications. SICADS has been designed to isolate site specific information into data files so that it can be easily tailored to fit a site's requirements without changing the software. Using SICADS, it is possible to generate systems which distribute processing and control over several computers and consoles. 1 fig.

The ion-hose instability can catastrophically disrupt a classical electron beam propagating in the ion-focussed regime (IFR). Ion hose is driven by a resonant interaction between the smooth electron-betatron and ion-betatron orbits. In a classical beam phase correlations decay secularly in time c(t)/c(t{sub 0}) {approximately} (t{sub 0}/t){sup n} (0 < n {le} 2). In a stochastic electron beam the electron orbits are chaotic. Such a beam can be immune to resonant instabilities because phase correlations decay exponentially fast c(t)/c(0) {approximately} e{sup {minus}ht} thus destroying the coherence of the electron response on the growth time 1/{gamma}{sub g} if h {approximately} {gamma}{sub g}. Using the same principles we can also envision a stochastic damping cell in which electron phase correlations damp exponentially c(z)/c(0) {approximately} e{sup {minus}hz} thus centering and conditioning a beam more effectively than a classical phase-mixing cell in which c(z)/c(z{sub 0}) {approximately} (z{sub 0}/z){sup n}. A triple-Bennett'' IFR system and the analogous triple-wire'' damping cell are analyzed. The K-entrophy is introduced as a figure-of-merit for such stochastic electron beam systems. 16 refs., 7 figs.

The chemical bonding and isochronal annealing of H implanted into GaAs at 80 K has been investigated by infrared absorption measurements. Based upon the frequency shift when deuterium is substituted for H, and an equivalent band formation in InAs, assignment of a new band at 2029 cm{sup {minus}1} is made to As-H centers. Bonding of H at interstitial As of and As-vacancy pair which anneals between 150 and 250K is suggested as the structure for the defect. A previously-reported absorption band at 1834 cm{sup {minus}1} assigned to Ga-H centers in H-implanted GaAS increase in intensity when H is released from As-H centers. 15 refs., 5 figs.

Strained layer structures have received a great deal of attention due both to their possible application in electronic devices and their intrinsic interest. The study of strained layer quantum wells grown using lattice mismatched materials has been widely developed for III-V semiconductors. Strained layer quantum wells grown using II-VI materials have not been studied nearly so much as those from III-V, but they are a rapidly growing field of semiconductor research. The wide gap II-VI materials are of interest because they are generally direct gap materials. This makes them attractive for optoelectronic devices. The majority of the work on strained layer structures in the wide gap tellurium based materials has focused in two areas. The first is the inclusion of Mn to produce dilute magnetic semiconductors (DMS) strained layers and superlattices. The other area is CdTe/ZnTe quantum wells and superlattices. Some related work has been done with CdZnTe/ZnTe structures. For the CdZnTe/CdTe very little work has been done and the majority of that used very small amounts of Zn. In this paper we will present the growth and optical characterization of Cd{sub 1-x}Zn{sub x}Te/CdTe strained single quantum wells (SSQW) where the Zn concentration ranges from about 10 to 50%. 10 refs., 3 figs.

Apollo's OmniBack backup system provides a convenient and effective way of storing network backup information on 8mm tape. In addition it has a journaling facility to write extensive log files, recording the backup process in almost any degree of detail desired. The directory structure and file names used are logical and well-defined. Summary files announce the degree of success of the backup as specified in the work file. The system will run unattended under the UNIX cron command, allowing the backup to be performed during the night when user demands on the network are small and most user files are free.

Agencies that are prime contractors to the Department of Energy (DOE) have developed and are currently instituting a quality initiative which applies a QML-like methodology to a complete discrete semiconductor process. Our goal is to demonstrate that improving the quality of this process is a more efficient method than screening to improve the quality of the semiconductor. The QML methodology, MIL-I-38535, is used to achieve this goal for integrated circuits. Our methods, for discrete semiconductor, applies many of the principles found in this specification to provide structured continuous improvement. Improvement in product performance reduces incoming inspection requirements, resulting in reduced cost and product lead time. This paper describes our methodology for this initiative, which consists of a certification, qualification, and monitoring (CQM) program for the complete semiconductor process. This process includes all technical and administrative activities that effect the quality of a device, beginning with circuit design and ending with the installation of the manufactured device into the electronic component assembly. For the initial application, our CQM program is being implemented on a small signal transistor. Four companies are involved in the partnership: Sandia National Laboratories, a design agency and prime contractor to the DOE; Allied-Signal Aerospace Company, Kansas City Division, a production agency and prime contractor to the DOE (for electronic component assembly); Alliance Electronics, a prime contractor and supplier (for procurement and testing); and Motorola Inc., Semiconductor Products Sector, a manufacturer. 2 refs.

The Department of Energy (DOE) is investigating the use of ductile cast iron (DCI) as a candidate material for radioactive material transportation cask construction. The investigation will include materials testing and full-scale cask testing. The major effort will focus on materials qualification and cask evaluation of the 9 meter and puncture drop test events. The test plan shall include a series of drop tests, and several core bars will be removed from the casting wall for material properties testing. Of particular interest is the evaluation of the material microstructure and fracture toughness parameters. Test instrumentation, used to define cask deceleration loads and strain during the drop tests, will be strategically placed in areas of the greatest structural interest. Part of the testing will include placement of an induced flaw. At the conclusion of the cask drop tests, the induced flaw(s) will be sectioned from the cask body for metallurgical examination. All test results will be documented in the safety analysis report for packaging for submission to the US Nuclear Regulatory Commission (NRC). The goal of this program is a certificate of compliance for DCI from the NRC to transport high-level radioactive materials. The acceptance of DCI within the USA cask design community will offer an alternative to present-day materials for cask construction, and its entry has the potential of providing significant cost-savings.

A three generation family of CMOS silicon test chips for packaging diagnostics has been developed. These Assembly Test Chips (ATC) contain sensors that measure a number of variables associated with assembled IC degradation, including the degree of IC corrosion, handling damage, ESD threat, ppm, moisture, mechanical stress, mobile ion density, bond pad cratering, and high speed logic degradation. The ATC family are intended to give manufacturing feedback in four ways: direct feedback in evaluation of an Assembly Manufacturing Line in an objective, non-intrusive way; before and after comparisons on an assembly production line when an individual process, material, or piece of equipment has been changed; resident lifetime monitor for system package aging and ongoing reliability projection and thermal, mechanical, dc electrical, and high frequency mock-up evaluation of packaging (including multichip) schemes. 14 refs., 6 figs., 2 tabs.

Infrared reflectance and transmittance measurements between 500 and 1800 cm{sup {minus}1} were obtained on boron carbides with between 10 and 20 atomic percent carbon. Measurements on both boron and carbon isotopically enriched samples indicate that all prominent modes involve boron motion, and that all but a mode near 950 cm{sup {minus}1} involve carbon motion. Since the spectrum remains qualitatively unaltered as a function of carbon concentration, its prominent features must have a common structural origin. 5 refs., 4 figs., 2 tabs.

The thermal neutron absorption cross sections of geologic materials are of first-order importance to the interpretation of pulsed neutron porosity logs and of second-order importance to the interpretation of steady-state porosity logs using dual detectors. Even in the latter case, uncertainties in log response can be excessive whenever formations are encountered that possess absorption properties appreciably greater than the limestones used in most tool calibrations. These effects are of importance to logging operations directed at geothermal applications where formation vary from igneous to sedimentary and which may contain solution-deposited minerals with very large cross-section values. Most measurements of cross-section values for geologic materials have been made for hydrocarbon production applications. Hence, the specimen materials are sedimentary and clean in the sense that they are not altered by geothermal fluids. This investigation was undertaken to measure cross-section values from a sequence of igneous materials obtained from a single hole drilled in an active hydrothermal system. 3 refs., 1 fig.

An automatic optical track identification/counting system has been developed for counting the total number of fission tracks on a fused quartz solid state track recorder. The system is capable of analyzing up to twenty recorders a day with an operator input of less than two hours. The uncertainty introduced by the counting system is about one percent. 6 refs., 2 figs.

A new runaway electron suppression paddle was designed with the PTA code package to reduce the runaway electron population in the Advanced Toroidal Facility (ATF), Oak Ridge National Laboratory. The PTA code package is a unique application of PATRAN, the Integrated TIGER Series, and ABAQUS for modeling high energy electron impact on magnetic fusion components and materials. By its nature, ATF is susceptible to runaway electron formation and confinement resulting in the production of a high level of hard x-rays near the machine. Four previous stainless steel paddles proved effective in reducing the runaway electron population; however, electrons above 15 MeV have still been observed. Melting and bending were observed in each of the previous paddles, reducing their effectiveness. Scoping experiments are under way to further characterize the runaway electrons in ATF. Data from these experiments will provide insight into runaway electron damage mechanisms. Proposals for the insertion of a new paddle in ATF are being considered. These analyses add to the knowledge of runaway electron damage and will aid in the design of future components to withstand runaway electron discharges in all magnetic fusion devices, including tokamaks. 8 refs., 3 figs., 1 tab.

System tuning often occurs in response to observed changes in key performance indicators. But, how do we determine if a change is significant Our indicators are random variables. They display a natural'' variation. This presentation reviews techniques that may provide a great deal of assistance in determining the significance of a change -- and more importantly -- when and what to tune. The techniques were developed by Dr. William Shewhart at Bell Labs and refined by internationally known quality specialist W. Edwards Deming. Although founded on statistical theory, the techniques are easy to use, require no formal statistical training, and may help you

The US Department of Energy National Photovoltaics Program considers the photovoltaic (PV) concentrator technology as a viable entity, likely to penetrate the utility market in the foreseeable future. To achieve this, it has launched the National Photovoltaic Concentrator Initiative under the management of Sandia National Laboratories. The objective of this program is to encourage PV concentrator system design and manufacture, with a view to bringing the energy cost to $0.12/kWh in the next four years and to $0.06/kWh by the year 2000. To achieve these goals, the systems have to perform reliably for 20 to 30 years. This necessitates a stringent quality assurance/quality control (QA/QC) program in all phases of PV concentrator design, production, and installation. In order to assist the PV industry in this effort a project was initiated to provide a generic QA/QC guide, capable of being adapted by any PV concentrator industry to prepare its individual QA/QC plan. The draft plan of the guide was prepared and circulated to various government laboratories and industries involved in PV concentrator work. Their input is now being incorporated into a final document, which will serve as an industry standard. 1 ref., 1 fig.

The design-basis, defense-related, transuranic (TRU) waste to be emplaced in the Waste Isolation Pilot Plant (WIPP) could, if sufficient H{sub 2}O and nutrients were present, produce as much as 1,500 moles of gas per drum of waste. Gas production could pressurize the repository to 150 atm (lithostatic pressure) and perhaps higher. Anoxic corrosion of Fe and Fe-base alloys and microbial degradation of cellulosics are the processes of greatest concern, but radiolysis of brine could also be important. The proposed backfill additives CaCO{sub 3}, CaO, CuSO{sub 4}, KOH, and NaOH may remove or prevent the production of some of the expected gases. Because of the heterogeneous nature of design-basis waste, the Eh and pH of any brine present in WIPP disposal rooms could vary significantly over short distances after reacting with the waste. The WIPP Project is investigating the consequences of gas production and considering engineered alternatives, including reprocessing the waste, to reduce gas production rates or potentials. Reprocessing would also reduce the range of Eh and pH expected for the repository. 12 refs.

More than 20 years ago, a philosophy was developed for the design and analysis of hardware systems to ensure that they would perform in a predictably safe manner, even in severe abnormal environments. This philosophy has been scrutinized and tested during the intervening years, and has proved successful in practice. A requirement guiding the development of the philosophy was that the resulting design must be simple enough to be amenable to analysis. The inherent simplicity is a safety attribute, because complex analyses, such as those represented by fault trees containing hundreds of branches, are extremely susceptible to error. There are many examples where such errors led analysts to believe systems were safe when they were not, with disastrous consequences. The purpose of this workshop problem is to determine whether the principles developed to ensure hardware safety are applicable in any way to safety-critical software systems. It is possible that hardware associations with software will need to be considered, but whether or not this is true is left as an aspect of the investigation. In order to put the ground rules in perspective, it will be necessary to establish some framework.

We present here the SMILE modification of the RADLAC II accelerator which enabled us to produce high quality 12--14 MV, 100 kA beams. It consists of replacing the 40-kA 4-MV beam injector, magnetic vacuum transport and accelerating gaps by a long cathode shank which adds up the voltages of the 8 pulse forming lines. The beam now is produced at the end of the accelerator and is free of all the possible instabilities associated with accelerating gaps and magnetic vacuum transport. Annular beams with {beta}{perpendicular} {le} 0.1 and radius r{sub b} {le} 2 cm are routinely obtained and extracted from a small magnetically immersed foilless electron diode. Results of the experimental evaluation are presented and compared with design parameters and numerical simulation predictions. 6 refs., 7 figs., 1 tab.

A diode employing a thermionic cathode has produced 80 A beams at 200 kV for at least 6 {mu}s. Moreover, the diode operates at rates as high as 1 Hz. EGUN simulations of the experimental geometry agree with the experiments. Finally, simulation of a proposed diode geometry predicts a 1 kA, 500 kV beam.

An algorithm is presented or rendering scalar field data which reduces rendering times by as much as two orders of magnitude over traditional full resolution image. Less than full resolution sampling of the scalar field is performed using a fast ray tracing method. The sampling grid points are output as a set of screen based gouraud shaded polygons which are rendered in hardware by a graphics workstation. A gradient based variable resolution algorithm is presented which further improves rendering speed. Several examples are presented. 16 refs., 8 figs., 2 tabs.

Efficient conversion of radioactive decay to electrical power has been the goal of a number of past research efforts. One of these was the Elgin-Kidde nuclear battery. In this concept promethium-147 was used as a beta source which was then mixed with a phosphor to produce a radioluminescent (RL) source of light. The light source was coupled to silicon photovoltaic converters to create electricity. This photoelectric approach is being revisited using tritium based solid state compounds and advanced gas concepts to produce RL light sources being disclosed at this conference. Efficient conversion of the RL light energy to electrical energy imposes certain requirements on the semiconductor converter. These requirements will be discussed. Projections of power source electrical and physical characteristics will be presented based on reasonable design parameter assumptions. The words Power Supply'' usually evoke a vision of a rotating machine or chemical battery. However, today's technology is making increasing use of photonics, where information and even power can be moved through optical fibers. Brighter volumetric RL light sources open a whole new range of photonics-based applications, while solid state tritiated compounds provide the foundation for improved mechanical adaptability and safety. 4 refs., 6 figs., 1 tab.

We describe the development of the first all-organic, opitcally clear, radioluminescent (RL) light. Although gas-phase RL lights have been known for many years, a number of advantages accrue to solid state devices. These include greater ruggedness and ease of brightness scale-up. In our systems, tritium is covalently bound to an organic getter, which is dissolved in an organic monomer, along with appropriate scintillating dyes. The entire system cures by monomer polymerization due to the radiation field, resulting in a clear, glowing solid plastic block. We outline here the design considerations employed in producing these materials. 12 refs., 1 fig.

This paper describes MIDAS, the Mobile Intrusion Detection and Assessment System. MIDAS is a security system that can be quickly deployed to provide wide area coverage for a mobile asset. MIDAS uses two passive infrared imaging sensors, one for intruder detection and one for assessment. Detected targets are tracked while assessment cameras are directed to view the intruder location for operator observation and assessment. The dual sensor design allows simultaneous detection, assessment, and tracking. Control and status information is provided to an operator using a color graphics terminal, touch panel driven menus, and a joystick for control of the assessment sensor pan and tilt. 1 ref., 5 figs.

The initial reactions that occur during liquefaction can have significant impacts on process yields and downstream process conditions. Reactions that result in compounds with low molecular weights and decreased boiling points are beneficial, whereas retrogressive reactions, which yield higher molecular weight compounds that are refractory to further processing, give lower yields of desired products. The objectives of this research are to determine the process conditions that give rise to retrogressive reactions during preconversion processing and to identify methods for minimizing the occurrence of these reactions. Initial studies have been performed using dibenzyl ether as a compound to model ether linkages in coal. Results show that retrogressive reactions can occur at temperatures as low as 180{degree}C. The presence of a good hydrogenation catalyst and a hydrogen donor was found to minimize retrogressive reactions, whereas the presence of mineral matter, primarily clay minerals, and ZnCl{sub 2}, enhanced the reactions. 8 refs., 3 figs.

Under the sponsorship of the United States Nuclear Regulatory Commission (NRC), Sandia National Laboratories is conducting several research programs with the common goal of developing a complete methodology for the prediction of the ultimate pressure capacity, at elevated temperatures, of light water reactor (LWR) containment systems. These programs are collectively known as the Containment Integrity Programs. This paper will provide a brief overview of these programs. As a part of the Containment Integrity Programs, a series of scale model containment test have been conducted at Sandia including a 1:8-scale steel model and a 1:6 scale reinforced concrete model. The model were pneumatically pressurized up to point of functional failure; that is, the point at which the containment was no longer effective in preventing significant leakage past its pressure boundary. Also, a 1:10-scale prestressed concrete model has been hydrostatically tested in the United Kingdom under a cooperative agreement with the NRC and others. Because the containment pressure boundary consists of numerous mechanical and electrical penetrations, several independent test programs of typical penetrations have also been performed to determine their leakage behavior when subjected to severe accident conditions. Completed containment penetration research programs include testing of typical compression seals and gaskets, inflatable seals, a personal air lock and electrical penetration assemblies (EPAs). Also, an investigation of leakage due to ovalization of penetration sleeves has been conducted as a part of the scale model test. Currently, testing of the unseating equipment hatch of the 1:6-scale containment model is under way. 23 refs., 3 figs., 2 tabs.

The CONTAIN code is a system-level analysis tool developed for the USNRC, and is intended for best-estimate prediction of conditions which might occur in the containment building of a nuclear power plant during a severe accident. A key feature of the code is that it models the containment phenomena in an integrated manner. In particular, the CONTAIN code models some of the complex ways that thermal hydraulics and aerosol phenomena interact with each other. The Light Water Reactor Aerosol Containment Experiment (LACE) progarm is a program to aid researchers in their understanding of thermal hydraulic and aerosol behavior within containments. The purpose of this paper is to report on best-estimate LA-4 post-test calculations that have been completed with the most recent version of the CONTAIN code, version 1.11. An analysis of experimental data and review of the blind post-test CONTAIN calculations is used to justify a re-calculation of the experiment and to establish a best-estimate calculation. The best-estimate calculation shows that reasonably good agreement between thermal hydraulic predictions and data can be obtained with the current CONTAIN models by varying experimental parameters within their uncertainties. Furthermore, with the recently added solubility model for hygroscopic aerosols, the best-estimate calculation gives aerosol behavior that is in good agreement with aerosol data. 10 refs., 16 figs.

Sandia National Laboratories is in the process of upgrading the Central Computing Network, which is a large heterogeneous network providing scientific computing, file storage, output services, and remote access to network resources. The migration from the present HYPERchannel-50 technology to HYPERchannel-100 is currently in progress and plans to migrate to the Fiber Distributed Data Interface (FDDI) token ring architecture are being considered. A migration from a variety of proprietary protocols to a primarily TCP/IP environment is also in progress. In order to test the feasibility of the Network Systems Corporation FDDI technology platform, two test rings have been constructed. Ring A' consists of nine dual attached Data Exchange Units (DXUs) and ring B' consists of two dual attached DXUs. The rings are linked together using N715 DXUs. Other DXU models (with associated host computers where applicable) include N130s, an N220, N400s, and FE640 IP routers. Test data on fault isolation and recovery mechanisms, performance, IP routing (within and between rings), and monitor capabilities will be presented. Interoperability' data based on tests between DXUs and Sun FDDI workstations will also be presented. 14 figs.

Experiments at Sandia National Laboratories have studied the operation of the linear-induction accelerators, HELIA and Hermes 3, in positive polarity. These experiments have provided a unique opportunity to explore the consequences of multiple-cathode electron emission in magnetically insulated transmission lines. An examination of the total energy-canonical momentum distribution of the electrons explains the features of the magnetically insulated flow exhibited by these systems. Simple analysis based on the basic concept of pressure balance, in conjunction with particle-in-cell numerical simulations, shows how the line voltage is related to the anode and cathode currents. Two flow designations are introduced that can apply to multiple-cathode magnetically insulated transmission lines: full-gap flow (FGF), and locally emitted flow (LEF). 16 refs., 15 figs.

An extensive optical fiber (o.f.) cable plant has been constructed in the Central Computing Facility (CCF) of Sandia National Labs to support the NSC DX platform with the Fiber Distributed Data Interface (FDDI) network. The cable plant was designed to optimize flexibility, maintainability, expandability, performance, and capacity. More than 2km of fiber cable and over 3400 connectors were installed. Each component of the cable system was carefully evaluated in order to meet the design requirements and conform to standards. A detailed statement of work (SOW) was generated to assure proper implementation of the design by a qualified contractor. Following the installation of the o.f. cable plant, a heterogenous, production network was built to utilize the benefits of the new media and interfaces.

The optimized C{sub 2v} geometry of ortho-carborane, 1,2-C{sub 2}B{sub 10}H{sub 12}, is determined from Hartree-Fock calculations. For this geometry, a carbon atom is substituted for a boron atom at one of the 4 inequivalent boron sites and the ground-state unrestricted Hartree-Fock eigenvalues and molecular orbitals are found. One thus obtains the valence structure of the B(1s) core-excited molecule according to the Z + 1 approximation. The eigenvalue of the highest occupied molecular orbital is then subtracted from the experimental B(1s) ionization energy of the same site in ortho-carborane. This determines the excitation energy of the most tightly bound exciton for that site. Three of the sites yield nearly identical excitation energies of 191.9 eV; the fourth site yields an excitation energy of 190.9 eV. 8 refs., 1 fig., 2 tabs.

A large area surface source of Lithium plasma for use as an ion source in the PBFA-2 ion beam diode is described. BOLVAPS produces a 1--2 mm thick layer of Li vapor with a density approaching 1 {times} 10{sup 17} cm{sup {minus}3} by rapid ohmic heating of a thin film laminate, one layer of which contains Li. The principal design issues of the vapor source being built for use on the PBFA-2 accelerator are described. LIBORS uses 670.8 nm laser light to efficiently ionize the Li vapor. The results of small-scale Physics tests and full-scale component development are summarized. 13 refs., 6 figs.

An applied B-field ion diode has been operated at 21 TW on PBFA 2 to study beam generation and transport physics. The radial focusing 15-cm-radius diode utilized a pair of magnet coils in disc cathode structures to produce an axial B-field to minimize electron loss in the 16 mm anode-cathode gaps. The diode was different than used in the past with the cathodes 20% closer together and the B-field increased to 3.3 T at the midplane. The 2.5 MA beam originated from a 5-cm-tall ion emitting region and was transported toward the axis in a 12.5-cm-radius gas cell with 2-{mu}m-thick mylar window and a 5-Torr-argon gas fill. A surface flash-over plasma created by electron loss on wax-filled grooves in the anode produced a beam with comparable currents of proton and carbon ions. The experimental results include the spatial uniformity and time dependence of proton and carbon beam emission from the anode and the divergence and focusability of both beams. 10 refs., 13 figs.

Anomalous dispersion (the decrease in refractive index which is associated with absorption) can be used to produce a phase-matched condition for second harmonic generation. This process also gives rise to large increases in the useful second order hyperpolarizability. A new, soluble NLO dye with exceptionally low absorption near 400 nm has been used for anomalous dispersion phase-matching studies in thin films.

The weldability of alloys based on Ni{sub 3}Al and Fe{sub 3}Al is discussed. Both of these ordered alloy systems may experience problems associated with welding. In the case of Ni{sub 3}Al alloys, limited hot ductility contributes to heat-affected zone cracking. Fe{sub 3}Al alloys experience similar difficulties in zone cracking. Fe{sub 3}Al alloys experience similar difficulties in welding due to excessive grain embrittlement due to the presence of water vapor. Advances in both alloying and substructural refinement to improve the weldability are reviewed. 18 refs., 10 figs.

Methods of preparing non-agglomerated powders for three systems -- yttria, titania, and yttria-stabilized zirconia -- are reviewed. The non-agglomerated nature of these powders should make it possible to sinter them into dense ceramic bodies with nanocrystalline grain sizes. Experiments with yttria-stabilized zirconia have shown that this is indeed the case, with mean linear intercept grain sizes of 60 nm resulting from original powder particle diameters of 13 nm. This ultrafine-grained zirconia is shown, in turn, to have superplastic forming rates 34 times faster than a 0.3 {mu}m-grained commercial zirconia of the same composition. 7 refs., 9 figs.

The first commercially available GaAs 8K ROM has been designed and manufactured using GigaBit Logic's 3-level metal E/D process. The worst case clock frequency of 650 MHz has been obtained with a power dissipation of 3.5 W. The ROM is organized as 1K X 8 bits, and on-chip translation logic enables the ROM to have an effective 4K X 8 resolution when used a a sine look-up table. The ECL compatible ROM is packaged in GigaBit Logic's standard 40 pin package.

The weldability, solidification behavior, and solidification microstructures of Hastelloy{asterisk} Alloy B-2 and Hastelloy{asterisk} Alloy W have been investigated. Susceptibility to fusion zone hot-cracking was determined by autogenous Varestraint testing. High temperature phase transformations, including solidification events, were identified by differential thermal analysis (DTA). After testing, the microstructures of various specimens were examined by optical metallography, scanning electron microscopy (SEM), electron microprobe analysis, and analytical electron microscopy (AEM). Results of this study showed that Hastelloy B-2 has exceptional resistance to hot cracking, comparable to that of Hastelloy C-4 and 304 stainless steel, while Hastelloy W proved to be somewhat more susceptible to hot cracking, exhibiting behavior similar to Alloy 625. The solidification process in both Hastelloy B-2 and Hastelloy W was found to be dominated by the segregation of Mo which gives rise to the formation of terminal eutectic-like constituents. This pattern of segregation is consistent with that of previous work on other Ni--Mo--Cr alloys. The microstructural constituents associated with hot-cracking in each alloy have been identified. 13 refs., 8 figs.

The weldability of Haynes {reg sign} Alloy No. 242 {trademark}, a new alloy derived from the Ni-Mo-Cr system, was investigated. Susceptibility to fusion zone hot cracking was determined by Varestraint testing, and hot ductility was characterized by Gleeble testing. Solidification phase transformation data was recorded with differential thermal analysis (DTA). Weld microstructures were characterized with scanning electron microscopy (SEM), analytical electron microscopy (AEM), and electron probe microanalysis (EPMA). The results of this study indicate that this alloy has better hot cracking resistance than high strength nickel base superalloy 718; however, it has lower resistance than other alloys derived from the Ni-Cr-Mo ternary such as the Hastelloy alloys B2, C-4, C-22, C-276, and W. Segregation patterns in weld microstructures agree well with established information concerning this family of alloys. Prediction of solidification products with the Ni-Mo-Cr phase diagram based on a chemical equivalence was unsuccessful due to the higher carbon content of this alloy which favors the formation of M{sub 6}C. Solidification in Alloy 242 terminates with the formation of two eutectic-like constituents: (1) a M{sub 6}C/austenite eutectic, and (2) a second eutectic with austenite and an undetermined phase. This latter phase has a composition similar to the M{sub 6}C phase, but with a different crystal structure (cubic, ao = 6.6 {Angstrom}). 11 refs., 10 figs., 4 tabs.

In the Recirculating Linear Accelerator, we will inject a 10-kA to 20-kA electron beam, and then focus and guide it with an IFR plasma channel, which is created with a low energy electron beam. The REB will be transported through a closed racetrack or a spiral beam line to be re-accelerated by the ringing waveform of dielectric cavities. By adding more accelerating cavities along the beam line, high energies can be achieved. Experiments are in progress to study IFR beam transport issues. A new injector is needed for beam re- acceleration experiments. We are presently installing this new REB injector which will-provide a higher amplitude ({approximately}4 MV), longer duration ({approximately}40-ns FWHM), more rectangularly shaped({approximately}25-ns full width at 90% peak) waveform and a colder beam than were achievable with the previous 1.5-MV injector. The resultant constant beam energy can be more efficiently matched the guiding IFR plasma channel in the beam line and to the turning section magnetic fields. We are now developing new cavities that produce accelerating voltage pulses with improved waveform flatness, width, and amplitudes that do not suffer unacceptable degradation over the first four ringing periods. This effort requires network solver and electrostatic field stress analysis computer codes, and a scaled test model to compare actual waveforms to those predicted by the simulations. 10 refs., 9 figs.

Prior research has concentrated on damage at the Si--SiO{sub 2} interface caused by photoinjection of electrons into the oxide by near UV light. The damage processes involved may be similar to those responsible for degradation in the Stanford type, point contact solar cell (PCSC). 7 refs., 6 figs.

The electric field dependence of radiation-induced interface-trap formation has been reported to be different for metal-gate capacitors and polysilicon-gate capacitors and transistors. For metal-gate capacitors, interface-trap formation steadily increases with increasing positive field. On the other hand, for polysilicon-gate capacitors and transistors, interface-trap buildup peaks near fields of 1 MV/cm to 2 MV/cm and decreases with an approximate E{sup {minus}1/2} dependence at higher fields. The previously reported field dependence for interface-trap generation for Al-gate capacitors is consistent at all fields with McLean's physical explanation of the two-stage process, which depends on hydrogen ion (H {sup +}) release in the bulk of the oxide as radiation-induced holes transport to either interface via polaron hopping. Above 1 MV/cm, the field dependence of interface-trap buildup for polysilicon-gate devices is inconsistent with this model. Instead, it is similar to the field dependence for hole-trapping in SiO{sub 2}, suggesting that hole trapping may play a key role in interface-trap generation in Si-gate devices. However, recent studies of the time-dependence of interface-trap buildup have known that hole trapping cannot be the rate-limiting step in interface-trap buildup in polysilicon gate devices. Consistent with McLean's physical explanation of the two-stage process, the rate-limiting step in interface-trap formation appears to be H{sup +} transport to the Si/SiO{sub 2} interface. We will show that the electric field dependence of radiation-induced oxide- and interface-trap charge buildup for both polysilicon and metal-gate transistors follows an approximate E{sup {minus}1/2} field dependence over a wide range of electric fields when electron-hole recombination effects are included. Based on these results a hole trapping/hydrogen transport (HT){sup 2} model for interface-trap buildup is proposed.

Short communication.

The identification of unknown phases in the JCPDS-ICDD Powder Diffraction File (PDF) using diffraction data is a three-step process. First, the Search step rapidly screens the entire PDF to produce a list of candidate solutions that correspond to the unknown phase's d-spacings and chemistry. Second, the Match step examines closely every aspect of each phase in the candidate list, vs the unknown, to make the final identification. Third, the Decision step: Does the solution found make crystal-chemical-thermodynamic sense A hindrance to the identification process for electron diffraction applications is that the PDF consists of x-ray diffraction powder data. The present Elemental and Interplanar Spacing Index (EISI) book is based on the successful 1979 Max-d/Alphabetical Index rules, but with significantly enhanced capability, as it utilizes the combined NIST/Sandia/ICDD Database. The EISI is designed to be used independently as a searching tool. As a searching tool it provides a list of candidate phases for consideration as solutions to the unknown phase diffraction data. The EISI index was designed to assist the actual steps taken by an Analytical Electron Microscope (AEM) diffractionist when confronted with an unknown diffraction dataset: the assemblage and d-spacing searching of a microfile of data containing chemically correct phases. The construction of the NIST/Sandia/ICDD Database overcomes many of the disadvantages associated with searching x-ray derived databases for solutions to electron diffraction problems. 8 refs., 1 fig.

The activities involved in establishing a Computer Integrated Manufacturing (CIM) database at Sandia National Laboratories (SNL) are part of a common effort to implement a proactive data administration function across administrative and technical databases. Data administration activities include the establishment of corporate data dictionary, a corporate information model, and a library of important objects and their relationships with other objects. Processes requiring information will be identified and supported with future information systems that share administrative and technical data. The process to create databases is being established based upon accepted engineering design practices. This paper discusses the CIM database, presents the selected information modeling technique and describes the information engineering process. 9 refs.

Little work has been performed to characterize the exposure sensitivity, contrast, and tone of candidate resists for photon energies between 100--300 eV, the range in which projection soft x-ray lithography will be developed. We report here the characterization of near-edge x-ray absorption fine structure (NEXAFS) spectra, exposure sensitivity, contrast, and post-exposure processing of selected polysilane resists at photon energies close to the Si L{sub 2,3} absorption edge (100 eV). We find absorption resonance features in the NEXAFS spectra which we assign to excitation into Si--Si and Si--C {sigma}* orbitals. Using monochromatized XUV exposures on the Si--Si {sigma}* resonance at 105 eV, followed by solvent dissolution development, we have measured the exposure sensitivity curves of these resists. We find sensitivities in the range of 600--3000 mJ/cm{sup 2} and contrasts in the range from 0.5--1.4, depending on the polysilane side chain. We have also performed exposure sensitivity measurements at 92 eV, below the edge. Sensitivity decreases slightly compared to 105 eV exposures and the saturation depth and contrast both increase, as expected. We find also that exposing resist films to oxygen after XUV exposure, but before development increases the sensitivity markedly. 7 figs.

A simplified, rugged VISAR (Velocity Interferometer System for Any Reflector) system has been developed using a non-removable delay element and an essentially non-adjustable interferometer cavity. In this system, the critical interference adjustments are performed during fabrication of the cavity, freeing the user from this task. Prototype systems are easy to use and give extremely high quality results. 6 refs., 7 figs.

The High-Temperature Borehole Televiewer is a downhole instrument which provides acoustic pictures of the borehole walls that are suitable for casing inspection and fracture detection in geothermal wells. The Geothermal Drilling Organization has funded the development of a commercial tool survivable to temperatures up to 275{degree}C and pressures of 5000 psi. A real-time display on an IBM-compatible PC was included as part of the developmental effort. This paper describes the three principal components are: the mechanical section, the electronics, and the computer software and hardware. Each of these three components are described with special attention to important design changes most pertinent to a high temperature environment. The results of two field tests of the televiewer system are also described. 7 refs., 4 figs.

Early attempts at estimation of stress wave damage in blasting by use of finite element analysis met with limited success due to numerical instabilities that prevented calculations from being carried to late times after significant fragmentation had occurred. A new damage model based on microcrack growth in tension allows finite element calculations which remain stable at late times. Estimation of crater profiles for blasting experiments in granite, using laboratory properties for all parameters, demonstrate a high level of success for this damage model. However, estimated crater profiles show systematic differences from excavated crater profiles which motivate further developments of this model. 19 refs., 16 figs.

Borated stainless steel tensile testing is being conducted at Sandia National Laboratories (SNL). The goal of the test program is to provide data to support a code case inquiry to the ASME Boiler and Pressure Vessel Code, Section 3. The adoption by ASME facilitates a materials qualification for structural use in transport cask applications. The borated stainless steel being tested conforms to ASTM specification A-887, which specifies 16 grades of material as a function of boron content (0.20% to 2.25%) and fabrication technique. For transport cask basket applications, the potential advantage to using borated stainless steel arises from the fact that the structural and criticality control functions can be combined into one material. The test program at SNL involves procuring material, machining test specimens, and conducting the tensile tests. From test measurements obtained so far, general trends indicate that tensile properties (yield strength and ultimate strength) increase with boron content and are in all cases superior to the minimum required properties established in SA-240, Type 304, a typical grade of austenitic stainless steel. Therefore, in a designed basket, web thickness using borated stainless steel would be comparable to or thinner than an equivalent basket manufactured from a typical stainless steel without boron additions. 3 figs., 5 tabs.

The use of a negative coefficient of thermal expansion (CTE) mineral filler ({beta}-eucryptite) is examined as a means of reducing CTE of a bismaleimide polymer (Kerimid 601). Results show that {beta}-eucryptite is effective in lowering CTE of the polymer and of glass fabric composites with a filled matrix phase. A theoretical model is presented that effectively predicts CTE of the filled BMI but underestimates the observed results by approximately 15%. The lower predicted CTE is believed to be due to poor interfacial adhesion at the {beta}-eucryptite/bismaleimide interface. Poor interfacial adhesion is supported by ultimate tensile strength results. 27 refs., 7 figs., 3 tabs.

Diffusion-limited (heterogeneous) oxidation effects are often important for studies of polymer degradation. Such effects are common in polymers subjected to ionizing radiation at relatively high dose rate. To better understand the underlying oxidation processes and to aid in the planning of accelerated aging studies, it would be desirable to be able to monitor and quantitatively understand these effects. In this paper, we briefly review a theoretical diffusion approach which derives model profiles for oxygen surrounded sheets of material by combining oxygen permeation rates with kinetically based oxygen consumption expressions. The theory leads to a simple governing expression involving the oxygen consumption and permeation rates together with two model parameters {alpha} and {beta}. To test the theory, gamma-initiated oxidation of a sheet of commercially formulated EPDM rubber was performed under conditions which led to diffusion-limited oxidation. Profile shapes from the theoretical treatments are shown to accurately fit experimentally derived oxidation profiles. In addition, direct measurements on the same EPDM material of the oxygen consumption and permeation rates, together with values of {alpha} and {beta} derived from the fitting procedure, allow us to quantitatively confirm for the first time the governing theoretical relationship. 17 refs., 3 figs.

This paper will focus on the electronic and photochemical properties of polysilylenes, with particular emphasis on the many resemblances in the electronic properties of polysilylenes to those of the familiar {pi}-conjugated polymers. In this context, the term {sigma}-conjugation'' will appear in this paper, as it is almost universally prevalent in the field. However, the use of this term should only be interpreted to suggest a correspondence in the electronic properties with those of {pi}-conjugated materials. No direct correspondence in electronic interactions at the atomic level is implied. In fact, the theoretical underpinnings of the mechanism of electron delocalization in {sigma}-bonded systems remain incomplete, at best. The systematic name polysilylene'' will be used in place of the equivalent and widely used term polysilane.'' In this context, these terms are intended to refer to polydiorganosilylenes, i.e. silicon backbones having substituents other than hydrogen. Moreover, since, with the exception of the commercial use of the intractable polydimethylsilylene as a precursor to {beta}-Sic fibers, the overwhelming majority of the interest in the field is in soluble polysilylenes, the discussion here will be of that greatly predominant group of the materials which are fully tractable and processible. 75 refs., 4 figs., 2 tabs.

Short communication.

We have demonstrated that CI{sub 2} RIBE is a useful dry-etch technology for InSb and InAsSb/InSb Strained-Layer Superlattices (SLSs) in spite of the low vapor pressure of the In chlorides. Etching of these materials using both Cl{sub 2} Reactive-Ion-Beam Etching (RIBE) and Ar IBE resulted in extremely smooth surfaces and well controlled etch rates with CI{sub 2} RIBE accelerating the etch rate by approximately a factor of two compared to Ar IBE over the range of beam energies studied. Sloped sidewalls resulted at all tested Cl{sub 2} RIBE energies and are probably caused by sidewall passivation with In chlorides. The anisotropy and reduced etch-induced damage of Cl{sub 2} RIBE is expected to become of critical importance in the fabrication of dense arrays of long-wavelength photodetectors. 2 figs.

A sol-gel method was use to prepare bulk, closed pore, amorphous alumina-silica. Films prepared from this 47wt% Al{sub 2}O{sub 3}- SiO{sub 2} composition were examined by SAW, elipsometry and electrical measurements. The films were found to have a surface area of 1.1 cm{sup 2}/cm{sup 2}, a refractive index of 1.44 at 633 nm, and a relative permittivity of 6.2 at 200 KHz. These properties indicate potential applications as hermetic seals, barrier coatings, dielectric layers for capacitors and passivation coatings for electronic circuits.

Short communication.

We report on the rapid thermal processing (RTP) of Y-123 fibers with and without presintering to form the orthorhombic phase. We show that fibers which were originally semiconducting and tetragonal before rapid thermal processing form normal twinned orthorhombic material after processing for 2--4 seconds at > 1000{degrees}C with a 3 min. cool down in oxygen. They subsequently show {Tc} to 90K and magnetization indicative of substantial diamagnetic shielding. We present the effects of varying the RTP parameters on the morphology, phase, and superconducting properties of a number of tetragonal and orthorhombic Y-123 fibers. 2 refs., 5 figs., 1 tab.

There has long been a need for fast read nonvolatile, rad hard memories for military and space applications. Recent advances in EEPROM technology now allow this need to be met for many applications. Harris/Sandia have developed a 16k and a 256k rad hard EEPROM. The EEPROMs utilize a Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) memory transistor integrated into a 2 {mu}m, rad hard two level metal CMOS process. Both the 16k and the 256k parts have been designed to interface with the Intel 8085 or 80C51 and National 32000 series microprocessors and feature page and block clear modes. Both parts are functionally identical, and are produced by the same fabrication process. They are also pin for pin compatible with each other, except for the extra address and ground pins on the 256k. This paper describes the characteristics of this EEPROM family. 1 ref.

The concentrations of carbon dioxide, methane, sulfur dioxide, nitrous oxides and chlorofluorocarbons is increasing in the earth's atmosphere. Increased concentrations of these trace gases could lead to global warming, increased acid rain and increased UV radiation on the earth's surface; however, the actual impacts are still uncertain and are also the subject of great debate. Application of clean'' energy sources such as geothermal are obviously desirable for decreasing these effects and improving our overall general environment. This paper briefly summarizes the global environment concerns, providing a backdrop for the following papers which describe the geothermal role in future environmental considerations. 5 refs., 2 figs., 1 tab.

Many of the applications that require the unique capabilities of Photoconductive Semiconductor Switches (PCSS) demand a compact package. We have been able to demonstrate that GaAs switches operated in the high gain mode called lock-on'' meet the required electrical switching parameters of several such applications using small switch sizes. The only light source that has enough power to trigger a PCSS and is compatible with a small package is a laser diode. This paper will describe the progress that leads to the triggering of high power PCSS switches with laser diodes. Our goal is to switch up to 5 kA in a single shot mode and up to 100 MW repetitively at up to 10 kHz. These goals are feasible since the switches can be used in parallel or in series. Low light level triggering became possible after the discovery of a high electric field, high gain switching mode in GaAs (and later in InP). At electric fields below 3 kV/cm GaAs switches are activated by creation of, at most, only one conduction electron- valence hole pair per photon absorbed in the sample. This linear mode demands high laser power and, after the light is extinguished, the carriers live for only a few nanoseconds. At higher electric fields GaAs behaves as a light activated Zener diode. The laser light generates carriers as in the linear mode and the field induces gain such that the amount of light required to trigger the switch is reduced by a factor of up to 500. The gain continues until the field across the sample drops to a material dependent lock-on field. At this point the switch will carry as much current as, and for as long as, the circuit can maintain the lock-on field. The gain in the switch allows for the use of laser diodes. 8 refs., 11 figs.

Experimental laminar condensation heat transfer data is reported for fluids with Stefan number up to 3.5. The fluid is a member of a family of fluorinated fluids developed in the last decade which have been extensively used in the electronics industry for soldering, cooling, and testing applications. Experiments were performed by suddenly immersing cold copper spheres in the saturated vapor of this fluid, and heat transfer rates were calculated using the quasi-steady temperature response of the spheres. In these experiments, the difference between saturation and wall temperature varied from 0.5{degree}C to 190{degree}C. Over this range of temperature difference, the condensate properties vary significantly. For example, viscosity of the condense varies by a factor of over 50. Corrections for the temperature dependent properties of the condensate therefore were incorporated in calculating the Nusselt number based on the average heat transfer coefficient. The results are discussed in light of past experimental data theory for Stefan number less than 1. To the knowledge of the authors, this is the first reported study of condensation heat transfer for Stefan number greater that unity. 24 refs., 7 figs., 2 tabs.

A method is presented for determining the force spectral density function for a vibration test where a combination of force and acceleration is used for control. First the acceleration spectral density is established based on an envelope of the interface motion between the test item and the mounting structure (the base) in the use (field) environment. The driving point accelerance (acceleration/force) of the test item is measured at the mounting interface. The force required to drive the test item in an acceleration controlled test is then estimated. A force spectral density is then established using the estimated motion controlled force, and a derived force reduction factor. An extremal control vibration test is then performed based on which parameter (input force or input acceleration) reaches based on which parameter (input force or input acceleration) reaches its envelope first. 7 refs., 7 figs., 2 tabs.

This paper presents the results of an experimental study of the thermal stability in air and vacuum of the codeposited carbon/hydrogen layer formed in a carbon-lined fusion reactor. Results are also presented for the stability of the saturated layer formed by the implantation of energetic hydrogen ions into a graphite surface. For both films, the hydrogen isotope release occurs at a much lower temperature in air than it does in a vacuum. At temperatures above 600 K, the hydrogen isotope release in air is very rapid and is emitted in a condensible form. It is speculated that isotopic exchange with the water present in air is responsible for this release. In vacuum, temperatures in excess of 1000 K are required to produce a rapid release from either film. The implications of these results to the safety of tritium in carbon-lined fusion reactors are discussed. 24 refs., 2 figs.

Laboratory deformation and permeability measurements have been made on chalk samples from Ekofisk area fields as a function of confining stress and pore pressure to determine the effective stress laws for chalk. An understanding of the effective stress law is essential to obtain correct reservoir-property data from core analysis and is critical for reservoir management studies and reservoir compaction models. A powerful statistical technique known as the response surface method has been used to analyze our laboratory data determine the form of the effective stress law for deformation and permeability. Experiments were conducted on chalk samples that had a range of porosities from 15% to 36%, because porosity is the dominant intrinsic property that effects deformation and permeability behavior of chalk. Deformation of a 36% porosity chalk was highly nonlinear, but the effective stress law was linear, with {alpha} equal to about unity. Lower-porosity samples showed linear strain behavior and a linear effective stress law with {alpha} as low as 0.74. Analysis of the effective stress law for permeability is presented only for the lowest porosity chalk sample because changes in permeability in the higher-porosity chalk samples due to increasing confining stress or pore pressure were not were large enough, to deduce meaningful effective stress relationships. 15 refs., 8 figs., 2 tabs.

In actual circuit application, MOS transistor bias is generally not constant through radiation exposure. Nevertheless, the overwhelming majority of radiation effects studies and hardness assurance testing is performed at constant bias for simplicity and practicality. In the past 15 years, however, it has been shown that oxide- and interface-trap charge buildup and annealing during switched-bias exposures can differ quantitatively and qualitatively from that observed during steady-state exposures. This has made it difficult to develop predictive models of MOS circuit response for actual use conditions, and has introduced uncertainty into hardness assurance testing of MOS circuits. In this summary, defect growth and annealing rates are compared for steady-state and switched-biased irradiations of MOS transistors. A simple method is described to predict MOS oxide-trap charge, interface-trap charge, and mobility degradation during switched-bias exposures from steady-state ( on'' and off'') irradiations. Over a wide range of switching conditions for the devices examined, this method has provided predictions typically accurate to within better than 20%. The maximum error observed to data is less than 40%. This method should allow the total-dose radiation response of MOS circuits in real-use scenarios to be modeled with improved accuracy and flexibility. 9 refs., 3 figs.

Drillhole H-16 is an exploratory test hole, 850.9 ft deep, drilled in eastern Eddy County, New Mexico, to study the hydrologic parameters of possible aquifers and how these aquifers could affect the construction and maintenance of a shaft to be located about 54 ft from the drillhole. This shaft will connect the underground working of the WIPP (Waste Isolation Pilot Plant) site to the surface. Oeophysical logs were taken to measure acoustic velocities, density, radioactivity, porosity, and formation resistivities. This report describes the data collected during the drilling of exploration drillhole H-16. 2 refs., 2 figs., 3 tabs.

Recent legislation mandated the improvement of national competitiveness as a mission of the defense programs of the US Department of Energy. As a consequence, technology transfer --- the process of transferring commercially valuable technologies developed under government sponsorship to industry for commercialization --- is becoming an important emphasis at many DOE laboratories. Technology transfer processes take many forms, and there are different perspectives on how to approach this activity. In this paper, a taxonomy of technology transfer processes at a national laboratory is presented. In addition, the focus and rationale of Sandia National Laboratories' unique new initiative called the Technology Maturation Program is discussed. This program is designed to complete one essential element of technology transfer that advanced technologies toward commercial applications to the point that industry is willing to assume the investment risk. Strategies and program plans designed to improve the effectiveness of Sandia's contribution to enhancing US industry's competitive position in world markets are also presented.

ENDF/B-VI cross sections were released to the testing community in January 1990. Work at Sandia National Laboratories, with pre-released versions of the new cross sections indicates that changes in the neutron-induced charged-particle reactions will significantly affect 14-MeV neutron dosimetry. Reactions that are important for fission reactor dosimetry were examined and most did not change significantly. 12 refs., 3 figs., 3 tabs.

We have systematically varied processing parameters to fabricate PZT 53/47 thin films. Polycrystalline PZT thin films were fabricated by spin depositing Pt coated SiO{sub 2}/Si substrates with alkoxide solutions. Our study focused on two process parameters: (1) heating rate and (2) excess Pb additions. We used rapid thermal processing techniques to vary heating rates from 3{degree}C/min to 8400{degree}C/min. Films were characterized with the following excess Pb additions: 0, 3, 5, and 10 mol %. For all process variations, films with greater perovskite content had better ferroelectric properties. Our best films were fabricated using the following process parameters: an excess Pb addition of 5 mol %, a heating rate of 8400{degree}C/min and annealing conditions of 700{degree}C for 1 min. Films fabricated using these process conditions had a remanent polarization of 0.27 C/m{sup 2} and a coercive field of 3.4 MV/m. 12 refs., 4 figs.

Lost circulation is the phenomenon where circulating drilling fluid is lost to fractures or pores in the rock formation rather than returning to the surface through the wellbore annulus. In geothermal drilling, lost circulation can be a serious problem that contributes greatly to the cost of the average geothermal well. A DOE-sponsored program is underway at Sandia National Laboratories to develop new technology for solving lost circulation problems. The Lost Circulation Technology Development Program currently consists of twelve projects in three areas: technology to plug porous and minor-fracture loss zones; technology to plug major-fracture loss zones; and technology to characterize loss zones. This paper describes the program and highlights recent progress. 12 refs., 10 figs.

The effects of total-dose irradiation on PbO-ZrO{sub 2}-TiO{sub 2} ferroelectric capacitors have been studied in detail. It is shown that significant total-dose degradation of ferroelectrics can occur at dose levels greater than 1 Mrad(Si). 6 refs., 5 figs.

PIC's (Power Integrated Circuits) are becoming increasingly important because they allow integration of high-voltage and high-current power transistors, precision linear control circuitry, and low-voltage logic gates on the same monolithic chip. Integration of power and control functions provide benefits in reduced weight and size, enhanced reliability, and lower costs over conventional designs using these same components packaged separately. However, commercial PIC technologies, including AT T's commercial BCDMOS technology, are susceptible to failure in radiation environments. The relative lack of radiation hardness of the AT T BCDMOS technology was previously reported at this conference. Radiation hardening of PIC technologies is significantly more difficult than for other IC technologies, primarily because of the integration of many different types of devices into the technology. To facilitate integration, different devices share processing sequences. Thus, no one device can be optimized independently of the remaining devices. Since each device has its own distinct radiation response, this adds another set of constraints on the optimization of the overall technology from the point of view of device performance and radiation response. The high-voltage requirements further complicates efforts to harden a PIC technology. Modifying one device to optimize one aspect of its performance can severely impact all the other devices in the technology. 4 refs., 5 figs.

The objective of this work is the development of numerical models of rock fragmentation by blasting that can be applied to oil shale recovery. Specifically, these models should be used to improve mining efficiency, evaluate alternative mining strategies and provide a basis for evaluating the blast design for in situ retort construction. 11 refs., 7 figs.

Studies of falling-ball rheometry in concentrated suspensions, embodying a combination of analysis experiment, and numerical simulation, are discussed. Experiments involve tracking small balls falling slowly through otherwise quiescent suspensions of neutrally buoyant particles. A theory has been developed relating the average ball velocity to the macroscopic suspension viscosity, and, for dilute suspensions, agreement is obtained with Einstein's sheared suspension viscosity. Detailed trajectories of the balls, obtained either with new experimental techniques or by numerical simulation, are statistically interpreted in terms of the mean settling velocity and the dispersion about that mean. We show that falling-ball rheometry, using small balls relative to the suspended particles, can be a means of measuring the macroscopic zero-shear viscosity without disturbing the original microstructure significantly; therefore, falling-ball rheometry can be a powerful tool to study the effects of microstructure on the macroscopic properties of suspensions. 25 refs.

Joining ceramics to metals requires solutions to both scientific and practical engineering problems. Scientific issues include understanding the fundamental nature of adhesion at metal-ceramic interfaces, predicting interfacial reactions, and understanding the relation between chemical bonding and mechanical stresses at the interface on the atomic level. Engineering a specific ceramic-metal joint requires finding the optimum among what may be inherently incompatible properties. The following review briefly outlines some of the different methods for joining ceramics. Following that, some fundamental aspects of ceramic joining are presented. The paper concludes with examples of ceramic bonding in several engineering ceramic systems.

The assumptions, approximations, and uncertainty in the 1-MeV equivalent silicon damage methodology are reviewed. A new silicon displacement kerma function, based on ENDF/B-VI cross sections, is presented and its shape is experimentally confirmed. The issue of an associated 1-MeV equivalent reference kerma value is discussed. 19 refs., 4 figs.

By recirculating a relativistic electron beam (REB) in phase with a repeating accelerating voltage, it is possible to construct compact, efficient, high voltage gradient, linear induction accelerators (LIA). Concerns about energy spreads due to degradation of our 1.1-MV, 34-ns duration accelerating activity repeating pulse shapes have resulted in our improving the 24-switch trigger system for the ET-2 cavity, and identifying critical factors in the cavity design that affect the pulse shape. We summarize the improvements (completed and proposed) for the existing ET-2 cavity pulsed power and the status of our design analysis and modelling for the new four-pass accelerating cavities that could produce a 20-MeV REB for RLA. 14 refs., 24 figs.

Long term reliability of solder joints in thick film Au hybrid microcircuits require either minimization of the solid state growth of intermetallics or verification that if present, they do not compromise component performance. Intermetallic compounds such as AuIn{sub 2} or AuSn{sub 4} arise from the solid state reaction between Au thick films and 50Pb--50In or 63Sn--37Pb solder alloys, respectively; they are undesirable due to their brittle mechanical behavior caused by lack of a sufficient number of independent slip systems for plastic deformation. In addition, they may alter the resistivity of a circuit and thereby alter electronic performance. This paper will present a brief overview of the Au thick film inks/solder alloy systems whose intermetallic growth kinetics have been characterized at SNL, Albuquerque for hybrid microcircuit electronic applications. 6 refs., 3 figs., 2 tabs.

Examination of the durability of zirconia-coated rigid disks in various environments reveals a sensitivity to the presence of water vapor during sliding. Vacuum and dry air yield contact durabilities of 300 to 400 m, while in 50% relative humidity air the contact life increases to about 20 km. The durability of amorphous carbon-coated disks was also found to be more sensitive to the presence of moisture than to oxygen. The dominant factors affecting wear are believed to be oxidation of metallic debris and interaction of the overcoat layer with water vapor. Tests with ferrite read/write sliders on carbon-coated disks suggest that the pin-on-disc test is a valid simulation of the tribological behavior of this system. Carbon film thickness measurements indicate that the carbon film remains intact without appreciable thinning until the point of failure. 25 refs., 12 figs., 1 tab.

A method is presented for smoothing and differentiating noisy data given on a rectangular grid. The method makes use of a one-dimensional smoothing algorithm to construct the solution to an associated two-dimensional problem. Smoothing parameter selection is automated using a technique that does not require prior knowledge of the amount of noise in the data. Numerical examples are provided demonstrating the application of the method. 4 refs., 8 figs., 2 tabs.

Drillhole H-12 was drilled where hydraulic data were needed to better establish flow characteristics existing south-southeast of the WIPP site. The fluid-bearing zones of interest are the Magenta and Culebra dolomite units of the Rustler Formation. Dissolution of halite in the Rustler Formation has occurred in the uppermost member, but has not yet begun in the lower halite-bearing members. Cuttings and cores were taken at selected intervals and geophysical logs were run over the entire depth of the hole. 3 refs., 2 figs., 3 tabs.

Research has shown that long-term hourly insolation data are necessary to properly size stand-alone photovoltaic systems. Even if these data are available, their direct use requires extensive computing capabilities and is not practical on a routine basis. This paper describes a three-step model that generates realistic long-term hourly insolations from average monthly insolations. The model executes rapidly on a personal computer and generates the hourly data needed to properly size stand-alone systems. The approach used to develop this model was unique in that system performance predictions rather than statistical properties were used to verify that the synthetic data were representative of actual data. Results of verification tests show that array sizes resulting from the synthetic data are within 6% of the array sizes resulting from actual hourly data for any system with at least two days of energy storage. 5 figs., 4 tabs.

Sandia designed, built, and tested prototypes of a new photovoltaic concentrator module, the Sandia Baseline Module 3 (SBM3). The SBM3 is intended to be a high-efficiency module that can be readily adapted for commercial production. It consists of a 2 by 12 parquet of lenses arranged with 24 cells in an aluminum housing. The geometric concentration ratio is 185. The cells were made at the University of New South Wales and employ prismatic covers designed by ENTECH. The module features a new concept in cell assemblies in that the cells are soldered directly to a copper heat spreader, eliminating the expensive ceramic wafer and heat sink that have been used in previous designs. Electrical isolation was accomplished by anodizing the electrophoretically coating the aluminum housing. Lessons learned during construction and testing of the SBM3 are presented, along with the outdoor performance characteristics of prototype modules and results from qualification testing. 7 refs., 11 figs.

The Sandia Sorption Data Management System (SSDMS II) stores and retrieves trace element sorption data. The data management system has potential applications in performance assessment studies of transuranic high- and low-level, and toxic waste sites. The current version stores information describing the degree of sorption, the compositions of rocks and solutions used in the sorption experiment, and the experimental procedures. This User's Manual describes SSDMS II data searches, creation of new data files, and the merging of new with existing data base files. These extended data bases can be used to examine relationships among experimental variables, mineralogy of the substrate, water composition, and sorption ratios. Examples of using SSDMS II with a data base of radionuclide sorption data are given. 3 figs., 13 tabs.

Under the sponsorship of the US Department of Energy Office of Defense Programs, Sandia National Laboratories' Transportation Technology Center has developed computerized software to assist state and local governments in determining highway routing alternatives for radioactive materials. The techniques have a still wider application in analyzing route alternatives for all hazardous materials transport activities. The specific techniques discussed in this presentation are the latest update of the StateGEN/StateNET model structure and routing algorithm which contains the codified US Department of Transportation (DOT) Guidelines for Highway Route Controlled Quantity shipments of radioactive materials. 6 refs.

The 1/f noise of MOS transistors has been measured as a function of total ionizing dose and postirradiation biased annealing time. Comparison to oxide and interface trapped-charge buildup and annealing is discussed. 13 refs., 3 figs.

Significant improvements in CMOSIC quality, reliability, and fabrication yield can be readily achieved in the 1990s by appropriate implementation of tests for quiescent power supply current (I{sub DDQ}). As part of an overall quality management program, I{sub DDQ} testing incorporated with design for testability and modified conventional logic response testing enables 100% stuck-at fault coverage, quality improvement goals of defective levels less than 100 PPM, and reliability greater than 0.999 for 30 years. 9 refs., 2 figs., 1 tab.

Gravitational forces have been found to be an important factor in defining the particle collection efficiency curve of inertial impactors for large particles. In general it was found that if the parameter {cflx G} = gW/V{sub 0}{sup 2} (g is the gravitational acceleration, W is the nozzle diameter and V{sub 0} is the average fluid velocity at the nozzle throat) in greater than 10{sup {minus}3}, the efficiency curve would shift to lower particle sizes. No effect could be seen for lower values of {cflx G}. 1 ref., 1 fig., 1 tab.

X-ray microanalysis by analytical electron microscopy (AEM) has proven to be a powerful tool for characterizing the spatial distribution of solute elements in materials. True compositional variations over spatial scales smaller than the actual resolution for microanalysis can be determined if the measured composition profile is deconvoluted. Explicit deconvolutions of such data, via conventional techniques such as Fourier transforms, are not possible due to statistical noise in AEM microanalytical data. Hence, the method of choice is to accomplish the deconvolution via iterative convolutions. In this method, a function describing the assumed true composition profile, calculated by physically permissible thermodynamic and kinetic modeling is convoluted with the x-ray generation function and the result compared to the measured composition profile. If the measured and calculated profiles agree within experimental error, it is assumed that the true compositional profile has been determined. If the measured and calculated composition profiles are in disagreement, the assumptions in the physical model are adjusted and the convolution process repeated. To employ this procedure it is necessary to calculate the x-ray generation function explicitly. While a variety of procedures are available for calculating this function, the most accurate procedure is to use Monte Carlo modeling of electron scattering. 9 refs., 1 fig.

TNF-doped Mylar is a new radiation-hard dielectric that has recently been qualified as a viable substitute for Mylar in capacitors. The advantage of TNF-doped Mylar is that it satisfies both the nuclear safety and radiation hardness requirements of weapons. Mylar is not radiation-hard. Aging and compatibility studies were carried out to insure that (1) TNF does not diffuse from the film during fabrication of the capacitor or during storage; and (2) there are no compatibility problems with aluminum foil (the conductor) or Fluorinert (the secondary dielectric). Losses of TNF were barely detectable during the vacuum bakes used in fabricating capacitors or during accelerated aging tests carried out below T{sub g} (70C) over a two year period in air. In other accelerated tests, no compatibility problems were detected with aluminum or Fluorinert. TNF-doped Mylar is now being used in the MC-4109 capacitor that was called out for use in SRAM II. We anticipate no age-related or compatibility-related problems with TNF-doped Mylar.

The equilibrium swelling of a number of elastomeric seals, commonly used in weapon components, was determined after they were exposed to a saturated solvent environment. The dimensional stability of these elastomers in the solvents varied considerably. Reasons for this are discussed and a method by which one may estimate the degree of swelling that these elastomers will undergo in a solvent environment is presented. 5 refs.

This paper surveys a few of the current issues in sol-gel reaction kinetics. Many times seemingly modest changes in reactants or reaction conditions can lead to substantial differences in the overall reaction rates and pathways. For example, qualitative features of the reaction kinetics can depend on catalyst concentration. At very high acid-catalyst concentrations, reverse are significant for TMOS sol-gels, while for moderate acid-catalyst concentrations, reverse reactions are substantially reduced. The reaction kinetics are substantially reduced. The reaction kinetics of two similar tetraalkoxysilanes: tetramethoxysilane (TMOS) and tetraethoxysilane (TEOS), can be markedly different under identical reaction conditions. Under acid-catalyzed reaction conditions, a TMOS sol-gel undergoes both water-and alcohol-producing condensation reactions while a TEOS sol-gel undergoes only water-producing condensation. The early time hydrolysis and condensation reactions of a TMOS sol-gel are statistical in nature and can be quantitatively described by a few simple reaction rate constants while the reaction behavior of a TEOS sol-gel is markedly nonstatistical. A comprehensive theory of sol-gel kinetics must address diverse experimental findings. 9 refs., 3 figs., 1 tab.

The performance of battery charge controllers and their effects on the system are a critical concern for stand-alone photovoltaic systems with battery storage. Many types of charge controllers are being marketed today, and designers need to understand more about their performance and compatibility with different kinds of batteries and systems. This paper describes the evaluations and selected interim test results from eight different models of small (approx. 10 amps) charge controllers. They are being subjected to a comprehensive test program including thorough electrical characterizations at selected temperatures, photovoltaic inputs and load levels. After electrical characterizations, the charge controllers are divided into concurrent evaluation paths. One path consists of side-by-side operational systems tests in which the charge controllers are installed in identical stand-alone PV systems. The other path consists of continuous environmental and electrical cycling in which the controllers are subjected to programmed electrical inputs, temperatures, and relative humidities. Recharacterizations of all controllers are addition, selected custom tests are performed on identical models to determine response to transients, installation issues and system compatibilities. The data presented here include measured electrical characteristics of the controllers, temperature effects, operational performance, and interface measurements at the array, battery and load. 8 refs., 9 figs., 4 tabs.

In the testing of active microwave components, a common test procedure is to evaluate a device's performance when subjected to an all-phase, constant-standing-wave-ratio (APCS) load pull. Such a test specification is useful in verifying a device's stability and mismatch performance. Typically, APCS pulls are tediously performed by hand, with manually operated tuners. However, with the advent of mechanical, computer-controlled tuners, it is how possible to automate this procedure. At Sandia, the goal was to integrate an APCS pull capability into a multi-test, single-connection tester. (The single-connection concept implies that many test, such as network analysis, spectral analysis, and noise figure measurements can be made from a one-time, device-to-tester connection). Consequently, the slide-screw tuner was the obvious choice due to its removable probe capability. Hence, it became necessary to develop a custom algorithm capable of utilizing the tuner in an impedance-finding mode. The general concept used in implementing this capability was to empirically characterize the tuner over and acceptable range of tuner positions, and then use this characterization to intelligently predict the tuner positions needed to present the desired impedance. 4 figs.

Conductor development is one of the major long term goals in high temperature superconductor research. In this paper we report on two promising processing technologies that have been utilized to produce superconducting HTS conductors. First, melt spun YBa{sub 2}Cu{sub 3}O{sub 7} fibers rapid thermal processed for 1--8 sec at 950 to 1075{degree}C have {Tc}'s to 92 K, J{sub c}'s to 1100 A/cm{sup 2} and the orthorhombic twinned morphology typical for high quality YBa{sub 2}Cu{sub 3}O{sub 7}. A processing matrix of time, temperature and composition for these fibers shows that slightly CuO-rich starting compositions give the best results. Second, silver tube encapsulated wires of Bi{sub 1.7}Pb{sub 0.3}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} have been made by extrusion, wire drawing and cold rolling. The resulting tapes show orientation of the crystallites, zero resistance up to 100K and improved magnetic hysteresis above 50 K. The combination of mechanical reprocessing and extended thermal anneals near 850{degree}C appears to significantly improve these materials. 13 refs., 7 figs.

This paper discusses the ability of an adaptive line enhancer (ALE) driven by the least-mean-squares (LMS) algorithm to track the frequency of a chirping signal in broadband noise. The dynamic behavior of the weights is described and a weight tracking error bound is derived in terms in chirp rate. Frequency tracking and weight behavior are illustrated in examples. 6 refs., 7 figs.

Microfabricated series-arrays of Josephson junctions have been developed which are capable of producing quantized voltage levels over a wide voltage range. These arrays have been used in a calibration system since February 10, 1987 to maintain the US Legal Volt at the National Institute of Standards and Technology (NIST, formerly NBS). A similar system within the Primary Standards Laboratory (which is operated for the Department of Energy, Albuquerque Operations Office by Sandia National Laboratories (SNL)) has been in operation since July, 1989. Measurements of the temperature dependence of the array's quantized voltage states and DC characteristics are reported here. 8 refs., 2 figs.

As computers become increasingly powerful, the constitutive models used in structural analysis codes become increasingly sophisticated. With the current generation of supercomputers, it now seems reasonable to consider incorporating relatively detailed representations of the multiaxial deformation response of engineering alloys. To aid in the development of such models and to allow measurement of their constituent parameters, we have designed a complex multiaxial deformation test system. The system to be described has been developed to perform non-proportional cycling of thin-walled metal tubes using internal/external fluid pressure and tensile/compressive axial loading. It has been added to an existing MTS 490 kN load frame with a PDP 11/34-based computer control system. Features of interest include; specimen grips, the high pressure chamber, the hydraulic intensifier and controller, and associated valving and switching. Initial software for this system has been written on the PDP 11/34 in the MTS MultiUser-BASIC language to perform simple proportional multiaxial cyclic deformation to a prescribed effective plastic strain limit.

This paper explains the newly implemented new material (NM) sampling rationale for weapon production developed by Frank W. Mueller, SNL/7266, and approved by DOE. Our experience with weapon production programs has been primarily limited to production lengths of five years or less. As more recent programs, such as the W80, are moving toward increasingly longer production phases, it has become apparent that our previous sampling rationale may have required excessive new material samples. 3 refs.

Radiation-induced interface traps in Si-gate MOS devices follow an E{sup {minus}1/2} electric field dependence for E {ge} +0.13 MV/cm when electron-hole recombination effects are included. A hybrid model involving hole trapping and hydrogen transport is suggested. 20 refs., 4 figs.

The Direct Absorption Receiver (DAR) concept was proposed in the mid-1970s as an alternative advanced receiver concept to simplify and reduce the cost of solar central receiver systems. Rather than flowing through tubes exposed to the concentrated solar flux, the heat absorbing fluid (molten nitrate salt) would flow in a thin film down a flat, nearly vertical panel and absorb the flux directly. Potential advantages of the DAR over conventional tubular designs include a substantially simplified design, improved thermal performance, increased reliability and operating life, as well as reduced capital and operating costs. However, before commercial-scale designs can be realized, a method for controlling droplet ejection from the panel must be developed. In this paper, we present a new DAR design, which has the potential to control these droplets. The design employs four flat panels that are sloped backwards 5 degrees, wind spoilers, and air curtains. A systems analysis is presented indicating that the levelized-energy cost of the quad geometry should be very similar to cylindrical geometry that was originally proposed for the DAR concept. 19 refs., 5 figs., 3 tabs.

A sodium reflux pool-boiler solar receiver has been tested on a nominal 75-kW{sub t} parabolic-dish concentrator. The purpose was to demonstrate the feasibility of reflux-receiver technology for application to Stirling-engine dish-electric systems. In this application, pool boilers (and more generally liquid-metal reflux receivers) have a number of advantages over directly-illuminated tube receivers. The advantages, to be discussed, include more uniform temperature, which results in longer lifetime and higher temperature available to the engine. 17 refs., 10 figs.

Over the next several decades, it is expected that the use of renewable energy technologies will greatly expand as these technologies mature, as the cost of conventional energy supply increases, and as the environmental impact of fossil fuel usage is better understood. A critical question is whether the impact of renewables, in terms of displaced fossil fuel use and reduced environmental effects, can be significant. Certainly, public policy will have dramatic effects on this question. Given a positive policy environment, renewables have the potential to displace a significant fraction of projected energy use within 30-40 years. For the United States, renewables could contribute as much as 25-55 exajoules of energy annually by the year 2030, or 15-35{percent} of the projected total US energy consumption. 12 refs., 6 figs.

Use of the MIT-SNL Period-Generated Minimum Time Control Laws for the automated increase of neutronic power from subcritical conditions has recently been demonstrated. The use of these laws is advantageous because they provide the speed at which a control device should be withdrawn in order to generate a specified period. Two strategies were investigated. The first was the direct use of the MIT-SNL laws for the entire transient, startup plus operation at power. The second was to add reactivity at a constant rate until criticality was achieved and then to transfer control to the MIT-SNL laws. Each was evaluated by both simulation and actual experiment under conditions of closed-loop digital control on the Annular Core Research Reactor that is operated by the Sandia National Laboratories. Both approaches were shown to be feasible. The former has the advantage that the power profile will be known during the startup. Its drawback is that an excessively high rate of reactivity change may be needed to initiate the transient. 16 refs., 9 figs.

An experimental study is described that evaluates the potential for using an acoustic borehole television technique to measure fracture dimensions in lost circulation zones encountered in geothermal drilling. A simulated wellbore was constructed of sandstone blocks with adjustable, inclined fractures, stacked in a barrel filled with water. A slim-hole televiewer was used to log the wellbore, and a computer was used to digitize and analyze the data. Televiewer signal perturbations caused by the fractures were studied to evaluate the effects of fracture thickness and signal amplification on the width of the signal perturbation in the digital record. It was found that the signal amplification is applied. Two techniques for determining the correct amplification are described. With the televiewer used in the present study, fractures thicker than 0.15 inch in a 5.1-inch wellbore can be measured to within an accuracy of 5--15%. Fractures as small as 0.031 inch can be detected but cannot be accurately and reliably measured. 1 ref., 15 figs.

We are continuing to see significant progress in the development of photovoltaic (PV) concentrator technology. New record cell and module efficiencies have been achieved, and improvements in cells, cell assemblies, and modules are increasing reliability and decreasing cost. The number of firms actively pursuing PV concentrator module technology has increased substantially in the last three years. Two new concentrator systems were installed last year, and more are likely to be installed in the near future. This paper describes the most significant developments of the last two years, including descriptions of advances in PV concentrator cell technology, module development and reliability activities, the new installations, a new Concentrator Initiative Program, and results of the latest costing study. 26 refs., 8 figs., 1 tab.

The cost goals and calculations in the Five-Year Plan for the National Photovoltaics Program assume that photovoltaic (PV) concentrator modules will have a reliable output and an operational life expectancy of 30 years.'' Although the modules in the few PV concentrator systems fielded to date have so far been reliable, they have not been in the field long enough to establish performance levels for 30 years and are not necessarily representative of newer concentrator designs. Thus, extensive testing and analysis are required to evaluate and establish the reliability of current concentrator module designs. Considerable research has been done to establish appropriate qualification tests, to understand component failure mechanisms, and to obtain reliable materials and designs. Surveys of fielded systems have been conducted and new test and analysis techniques have been developed in the process. This paper discusses the reliability of photovoltaic concentrator modules with an emphasis on the issues that are currently of most concern. 12 refs., 5 figs.

Erosion of POCO graphite by helium in PISCES-A was measured by carbon spectroscopy for a temperature range from 900{degree}-- 2000{degree}C, ion energies of 30--300 eV, ion fluxes of 1 {minus} 6 {times} 10{sup 22} m{sup {minus}2} s{sup {minus}1} and electro temperatures of 4--22 eV. Yields at low energies were higher than predicted in current models. The role of redeposition is discussed. 15 refs., 4 figs.

The In-situ Permeable Flow Sensor is a new type of implantable instrument under development at Sandia National Laboratories that uses thermal boundary layer pertubation techniques to rapidly determine the three-dimensional velocity vector of groundwater flow in soils or permeable geologic media. This sensor is based on the refinement of previous technology, the Convective Heat Flow Probe, developed for the scientific study of the flow of geothermal fluids in thermally active regions of the earth's crust. The Convective Heat Flow Probe was designed as a logging tool for use in open or uncased boreholes. The newer In-situ Permeable Flow Sensor is based on the same theoretical principles but is designed to be permanently buried at waste or cleanup sites where long term monitoring of groundwater flow is of interest. This instrument is sensitive to permeable flows as low as a few meters per year.

Simplified ATPG and fault simulation algorithms, reduced test set sizes, and increased fault coverage are achieved with I {sub DDQ} testing for stuck-at faults. In addition, I {sub DDQ} testing will detect logically redundant and multiple stuck-at faults, and improve the detection of non-stuck-at fault defects. 17 refs., 6 figs., 6 tabs.

The Department of Energy's Multiwell Experiment (MWX) is a field laboratory in the Piceance Basin of Colorado which has two overall objectives: to characterize the low permeability gas reservoirs in the Mesaverde Formation and to develop technology for their production. Different depositional environments have created distinctly different reservoirs in the Mesaverde, and MWX has addressed each of these in turn. This report presents a comprehensive summary of results from the fluvial interval which lies between 4400 ft and 6000 ft at the MWX site. The reservoirs consist of heterogeneous, amalgamated point-bar sequences which form broad meanderbelts which create irregular, but roughly tabular, reservoirs with widths of 1000--2500 ft. Separate sections of this report are background and summary; site descriptions and operations; geology; log analysis; core analysis; in situ stress; well testing, stimulation, fracture diagnostics, and reservoir evaluation in two separate sandstones; stress, fracture diagnostic, and stimulation experiments in an additional sandstone; supporting laboratory studies; and a bibliography. Additional detailed data, results, analyses, and data file references are presented as appendices which are included on microfiche. The results show that stimulation of fluvial reservoirs can be successful if proper care is taken to minimize damage to the natural fracture system. Both an accelerated leakoff phenomenon and the ability to alter the in situ stress were quantified. Overall, the fluvial interval offers the highest production potential of the three nonmarine intervals studied. 116 refs., 230 figs., 28 tabs.

This paper presents a discussion of the use of the Nijssen Information Analysis Methodology (NIAM) in the design of an experimenters database. This database is used by physicists and technicians to describe the configuration and diagnostic systems used on Sandia National Laboratories Particle Beam Fusion Accelerator II (PBFA II). The design of this database presented some unique challenges because of the large degree of flexibility required to enable timely response to changing experimental configurations. The NIAM user-oriented technique proved to be invaluable in translating experimenter's requirements into an information model and then to a normalized relational design.

The theory and practice of information engineering is being actively developed at Sandia National Laboratories. The main output of Sandia is information. Information is created, analyzed and distributed. It is the life blood of our design laboratory. The proper management of information will have a large, positive impact on staff productivity. In order to achieve the potential benefits of shared information a commonly understood approach is needed, and the approach must be implemented in a CASE (Computer-Aided Software Engineering) tool that spans the entire life cycle of information. The commonly understood approach used at Sandia is natural language. More specifically, it is a structured subset of English. Users and system developers communicate requirements and commitments that they both understand. The approach is based upon NIAM (Nijssen's Information Analysis Methodology). In the last three years four NIAM training classes have been given at Sandia. The classes were all at the introductory level, with the latest class last October having an additional seminar highlighting successful projects. The continued growth in applications using NIAM requires an advanced class. The class will develop an information model for the Ultimate CASE Tool.'' This paper presents the requirements that have been established for the Ultimate CASE Tool'' and presents initial models. 4 refs., 1 tab.

Sandia National Laboratories joined with two other laboratories, Los Alamos National Laboratory and Naval Research Laboratory, to study and implement a highly parallelized tracker/correlator algorithm. Significant progress was made at Sandia on a specific algorithm and code. This report summarizes the accomplishments by Sandia during FY '89 on this project. 12 refs., 4 figs., 2 tabs.

This paper and a companion paper show the traditional limits on amplitude and frequency that can be generated in a laboratory test on a vibration exciter can be substantially extended. This is accomplished by attaching a device to the shaker that permits controlled metal to metal impacts that generate high frequency, high acceleration environment on a test surface. A companion paper (Reference 1) shows that a sinusoidal or random shaker input can be used to generate a random vibration environment on the test surface. This paper derives the three response components that occur on the test surface due to an impact on the bottom surface and the base driven response from the shaker input. These response components are used to generate impulse response functions and frequency response functions which are used in the companion paper to derive power spectral density functions for the overall response. 9 refs., 8 figs.

High average power magnetic pulse compression systems are now being considered for use in several applications such as the High Power Radiation Source (HiPoRS) project. Such systems will require high reliability magnetic switches (saturable inductors) that are very efficient and have long lifetimes. One of the weakest components in magnetic switches is their interlaminar insulation. Considerations related to dielectric breakdown, thermal management of compact designs, and economical approaches for achieving these needs must be addressed. Various dielectric insulation and coating materials have been applied to Metglas foil in an attempt to solve the complex technical and practical problems associated with large magnetic switch structures. This work reports various needs, studies, results, and proposals in selecting and evaluating continuous coating approaches for magnetic foil. Techniques such as electrophoretic polymer deposition and surface chemical oxidation are discussed. We also propose continuous photofabrication processes for applying dielectric ribs or spacers to the foil which permit circulation of dielectric liquids for cooling during repetitive operation. 10 refs., 8 figs., 11 tabs.

This paper and a companion paper show that the traditional limits on amplitude and frequency that can be generated in a laboratory test on a vibration exciter can be substantially extended. This is accomplished by attaching a device to the shaker that permits controlled metal to metal impacts that generate a high acceleration, high frequency environment on a test surface. A companion paper derives some of the mechanical relations for the system. This paper shows that a sinusoidal shaker input can be used to excite deterministic chaotic dynamics of the system yielding a random vibration environment on the test surface, or a random motion of the shaker can be used to generate a random vibration environment on the test surface. Numerical examples are presented to show the kind of environments that can be generated in this system. 9 refs., 9 figs.

Charged-particle simulations in three dimensions are now performed routinely in the Pulsed Power Sciences Directorate at Sandia with the QUICKSILVER suite of codes. QUICKSILVER is a multitasked, finite-difference, three-dimensional, fully relativistic, electromagnetic, particle-in-cell code developed at Sandia. It is targeted for use on current and near-term supercomputers, such as the Cray X-MP/416, which are characterized by large, shared central memories and multiple processors. QUICKSILVER has already been used to simulate ion diodes, magnetically insulated transmission lines, microwave devices, and electron beam propagation. QUICKSILVER is actually a suite of codes; in addition to the main simulation code there are several support codes. The problem geometry is generated with a preprocessor and the simulation results are examined with one or more postprocessors. The MERCURY preprocessor assists the user in defining the mesh, boundary conditions, and other input parameters. The FLASH and AVS postprocessors are used to examine a wide variety of simulation output, including 3D rendering of particle positions, conductor surfaces, and scalar and vector quantities. The PLOTPFF postprocessor displays 2D slices and 1D pencils derived from 3D scalar and vector quantities. Additionally, time histories of various simulation quantities can be examined and manipulated with the IDR postprocessor. This paper describes the suite in detail. 9 refs., 4 figs.

We report the first experiments evaluating the beam generation by the new 4-MV RLA injector. Beams of 15 to 27 kA current were produced and successfully transported up to the first post-accelerating cavity (ET-2), 1.3 m downstream. The beam radius was measured with an x-ray pin-hole camera and found to be equal to 5 mm. We selected an apertured ion-focused foilless diode among the various available diode options. It is the simplest and easiest to operate and can be adjusted to provide variable beam impedance loads. Experimental results will be presented and compared with numerical simulations.

For many years, the protection and control of classified documents has been a concern of administrative and management personnel. Recent thefts of documents has increased this concern and has led to high level committee investigations into improved classified document protection techniques. Better methods must be found to improve classified document protection and control systems. From preliminary investigations, it was determined that there is not one technique or method that alone would provide adequate protection of classified documents. Instead, a systematic approach that would utilize several components must be used. These components would limit the unauthorized access to classified documents, improve the accountability of documents, increase the protection of documents during transfers, protest classified documents against unauthorized reproduction, protect classified documents against unauthorized removal from a security area, and verify that documents that have been flagged for destruction are actually physically destroyed. This study investigates several techniques that could be implemented in each of these six areas. 8 refs.

This is a brief report about a Sandia National Laboratory facility which can provide high-thermal flux for simulation of nuclear thermal flash, measurements of the effects of aerodynamic heating on radar transmission, etc

This paper summarizes a cost-benefit assessment of the seismic design of the waste-handling facilities associated with the prospective high-level waste repository at Yucca Mountain, Nevada. It provides a very brief description of the methodology used and the costs and benefits of varying design levels for vibratory ground motions and surface fault displacements for structures, components, and equipment that are important to safety in the waste-handling facilities. 3 refs., 7 figs.

The problem of radiative heat transfer through a gray, emitting, absorbing, and scattering medium with uniform optical properties is reduced to one without scattering through two techniques. One uses scaling laws, and the other uses a self-consistent effective gas temperature. The scaling laws are derived via the P1 approximation to the radiative transfer equation and can be applied to multidimensional problems with nonisothermal media. The effective temperature method is presently restricted to isotropic scattering and isothermal media. Both methods are evaluated in the current study as a function of scattering albedo, wall emissivity, and optical thickness for two different geometries, and two sets of wall and gas temperatures. The effects of scattering anisotropy are also assessed for the P1 method.

Unsteady Surface Element (USE) methods are applied to a model of a thermocouple wire attached to a thin disk. Green's functions are used to develop the integral equations for the wire and the disk. The model can be used to evaluate transient and steady state responses for many types of heat flux measurement devices including thin skin calorimeters and circular foil (Gardon) heat flux gages. The model can accommodate either surface or volumetric heating of the disk. The boundary condition at the outer radius of the disk can be either insulated or constant temperature. Effect on the errors of geometrical and thermal factors can be assessed. Examples are given.

The problem of determining the mechanical states inside wound capacitor rolls is addressed through the application of two dimensional, linear elasticity. Allowances are made for heterogeneous wound construction of the capacitor, orthotropic material behavior of the capacitor constituents, and arbitrary winding tension. A key element in the formulation is the derivation of material properties for a wound, orthotropic layer which is equivalent in behavior to a stack of dissimilar plies such as are actually wound on the capacitor simultaneously during one turn of the mandrel. The dissimilar plies are necessary by virtue of the conductor and dielectric materials which must be present in a capacitor. The derivation of predictive equations is based on winding the equivalent layer on an appropriate mandrel, followed by a recovery of the individual ply responses.

The determination of the fully plastic response and pressure limit of high pressure containment structures is of considerable importance in design. The plastic-strain response during and following autofrettage operations, in comparison with the limiting strain condition, is of special interest. This paper presents the results of an analysis method for thick wall, high pressure, cylinders where the effective plastic strain distribution through the thickness is the material response variable of primary interest. The limiting value of this effective plastic strain depends on the level of tensile-stress triaxiality which also varies through the thickness. This strain-to-failure criterion is used to predict the complete pressure versus strain response and the maximum pressure for test cylinders. A simple method of effective-stress versus effective plastic strain is employed. This model is quantified by data taken from uniaxial, tension, true-stress-strain curves and from the fracture zone of the tensile specimen. A sample calculation is included.

The linear induction accelerator RADLAC II (Radial Line Accelerator II) is being upgraded to produce a 20-MeV, 40-kA, annular electron beam. Prior to the upgrade, RADLAC II produced a 15-MeV, 15-kA electron beam. Modifications to the pulsed power, injector, and magnetic transport have resulted in a faster-rising flat-topped voltage pulse. A high-quality, 40-kA, 2.0-cm-diameter beam with a low perpendicular thermal velocity has been produced from the injector. The high-quality beam has been accelerated through two accelerating gaps. The final four accelerating stages are being added to RADLAC II, and transport experiments through the full accelerator are beginning. Simulations show that the beam quality will be maintained through the entire accelerator.

Experimental and theoretical work have demonstrated that a proper injector design results in the generation of very-high-brightness beams in a field-immersed foilless diode source which is suitable for use on RADLAC II (a high-current linear induction accelerator for electrons). Time-resolved characterization of the high-brightness immersed diode source was achieved using a time-gated, 2-D X-ray imaging technique. The experiments were performed on the 4-MeV IBEX accelerator and produced currents exceeding 40 kA in a 6-mm-radius, thin annular beam with a measured thermal transverse velocity of 0.1c. For currents of 30 kA, even brighter beams with β2+ = 0.07 were obtained. At lower currents, beams as small as 2 mm in radius were produced with a smaller cathode tip. In all cases, the measured parameters were consistent with 2-D, PIC (particle-in-cell) simulations.

A test method involving simultaneous imposition of temperature cycles and strain on discrete solder joints in a shear orientation is presented. The stress, microstructure, and number of cycles to failure were monitored. Cycles to failure were determined by a continuous electrical detection method. Sodler joints with composition 60Sn-40Pb and 40Sn-40In-20Pb were tested using the method at 20% shear strain. The 60Sn-40Pb alloy had a shorter fatigue lifetime than did 40Sn-40In-20Pb. This is attributed to heterogenous coarsening that concentrates strain in a small area of the 60Sn-40Pb microstructure. In contrast the 40Sn-40In-20Pb microstructure becomes refined. The heterogeneous coarsening also results in cyclic softening in 60Sn-40Pb, which was not observed in 40Sn-40In-20Pb. Failures initiated within the coarsened band in 60Sn-40Pb at Sn-Sn grain boundaries or phase boundaries. In contrast, failures initiated at the surface of 40Sn-40In-20Pb joints and propagated through both phases of the microstructure.

Three different ion beam transport schemes (achromatic lens, wire-guided transport, and Z-discharge channel) for the light ion beam driver for the Laboratory Microfusion Facility (LMF) are examined analytically. For each case the phase space acceptance area is investigated, including the effects of angular momentum. It is shown that, in real diode/transport configurations, there will be some angular momentum (i.e., φ0 ≠ 0) created, e.g., by combinations of diode microdivergence, beam steering errors, foil scattering, and gas scattering. Both the ballistic/lens case and the channel case can accept φ0 = 0 beams if they can be made, and can also tolerate certain amounts of φ0 ≠ 0. On the other hand, the wire case requires φ0 ≠ 0 in a carefully prepared manner. It is concluded that, in regard to angular momentum, the baseline ballistic case is the most accepting transport scheme. The channel transport scheme is less accepting. The wire transport scheme is the least accepting because it requires a tailored nonzero φ0 distribution to be fully accepted.

The nominal 1000-MJ yield of a Laboratory Microfusion Facility (LMF) pellet requires at least a 1.5-m-radius target chamber to contain the blast. A geometry has been identified that uses an annular ion beam with a center plug, has a total transport length of 4 m, and allows no direct line of sight from the target blast to the ion diode. An analytic model for an achromatic, two-lens system that is capable of transporting a 30-MV, 1-MA Li ion beam over this distance has been developed. The system uses both self-Bθ and solenoidal magnetic lenses. The beam microdivergence requirement is minimized by locating the final solenoidal lens at the target chamber wall. In the present work, the analytic model was verified by PIC (particle-in-cell) transport calculations. A realistic coil system has been designed to supply the required 2-T solenoidal fields. Simulations show that a lithium beam can be transported over the 4-m distance with better than 70% energy and power efficiency, delivering roughly 1 MJ/beam to the target if a 6-mrad microdivergence is achieved at the diode.

The FALCON (Fission Activated Laser CONcept) reactor-pumped laser program at Sandia National Laboratories is examining the feasibility of high-power systems pumped directly by the energy from a nuclear reactor. In this concept we use the highly energetic fission fragments from neutron induced fission to excite a large volume laser medium. This technology has the potential to scale to extremely large optical power outputs in a primarily self-powered device. A laser system of this type could also be relatively compact and capable of long run times without refueling.

The semiconductor product engineers job requires knowledge and expertise related to many different subjects. This report provides guidance for newcomers to product engineering and is a consise reference for all others involved in product engineering. Subjects addressed are Customer/Supplier interactions, component development sequence, production schedule support, component characterization, product specifications, test equipment requirements, product qualification, characterization and development reports, preferred parts list, standard packaging, and finally, classification and security considerations. This guide is intended to help standardize and simplify the component development sequence presently used in the semiconductor product engineering department. 3 figs., 2 tabs.

The Waste Isolation Pilot Plant (WIPP), located in southeastern New Mexico, is a research and development facility to demonstrate safe disposal of defense-generated transuranic waste. Performance assessment comprises scenario development and screening and probability assignment; consequence analysis; sensitivity and uncertainty analysis; and comparison with a standard. This report examines events and processes that might give rise to scenarios for the long-term release of waste from the WIPP and begins to screen and assign probabilities to them. The events and processes retained here will be used to develop scenarios during the WIPP performance assessment; the consequences of scenarios that survive screening will be calculated and compared with the standard. 84 refs., 4 figs., 3 tabs.

Coherent phase transformation occurs under conditions of stress wave loading and there are indications that transformation is dependent on the nonhydrostatic state of stress in the body. Studies under static loading show transformation proceeds at lower confining pressure when combined with shearing stress and similar effects appear to occur under stress-wave loading. Nonlinearities in the stress-strain behavior due to the transformation strain lead to complicated wave propagation, including wave separation and rarefaction shock waves. In the present study a thermodynamic theory of the combined elastic and phase transformtion deformation is developed which incorporates the interrelation of pressure and shear effects. The theory is focused on wave propagation in solids and is compared with earlier experimental work on Oakhall limestone. A thermodynamic Gibbs potential is derived for the material and a phase equilibrium relation identified, which constrains the volume and shape change through the transformation. The theory is extended to account for the effect of microstructural heterogeneities on the transformation process which has been observed experimentally.

This report describes a demonstration of the performance assessment methodology for the Waste Isolation Pilot Plant (WIPP) to be used in assessing compliance with the Environmental Protection Agency. This demonstration incorporates development and screening of potentially disruptive scenarios. A preliminary analysis of the WIPP disposal system's response to human intrusion scenarios produces preliminary complementary cumulative distribution functions (CCDFs) used to assess the compliance of the WIPP with the Containment Requirements of the Standard. The conceptual model of the disposal system consists of geologic, hydrologic, and disposal system subsystems along with the physical and chemical processes associated with these subsystems. Parameter values defining the systems contain uncertainties and modeling approximations of such a disposal system contributes to those uncertainties. The WIPP compliance assessment methodology consists of a system of techniques and computer codes that estimate releases of radionuclides from the disposal system, incorporating analysis of the parameter uncertainties in the estimates. Demonstration CCDFs are presented, but are not yet credible enough to judge the probability of compliance of the WIPP with the EPA Standard. 60 refs., 75 figs., 30 tabs.

The structural response of plasma armature railguns to the electromagnetic load imposed during operation has a significant effect on performance. The railgun support structure must minimize bore deformation; thus stiffness and strength are important design parameters. The step by step evolution of the design toward a structure which will tolerate operation with 500 to 700 kA rail currents is presented. The design effort started with the traditional rail/insulator core structure contained within a V-block which provides a preload. Non-linear dynamic analyses together with model tests were used to assess the effects of changes in geometry, materials, and preload on the railgun structural performance. 39 figs., 5 tabs.

The ignition of reactive powders by a semiconductor bridge (SCB) is analyzed by applying a multiphase flow model based upon the theory of mixtures. The hot plasma produced by the SCB permeates the cold granular explosive, deposits its latent heat upon fusing to the grains, therby heating the explosive granular surfaces to energy states required for self-sustained reaction. This mechanism is predicted to heat the granular explosive in a region local to the SCB to temperatures well above those required for thermal ignition. The analysis demonstates that this mechanism explains the prompt ignition of explosives using SCB's as opposed to the conductively controlled heating of conventional bridgewires. 16 refs., 14 figs., 1 tab.

AEROPLT is an interactive, user-friendly, general purpose plot code for plotting tabular data from multiple files. This DISSPLA-based code is convenient and easy to use while permitting great flexibility for users who want to customize their plots. A series of questions leads the user through the program and permits a return to specific portions of the code for plot refinement. Multidevice capability permits the user to plot on the terminal, write to a file for hardcopy plots, or do both simultaneously. An easily modified Setup File is used to store the terminal and hardcopy type codes, plot and text dimensions, and default plot specifications. Parameters for individual plots are written to a Restart File which can easily be edited to change subsequent plots. Additional capabilities are: color plots; a convenient method (similar to TEX) to implement all DISSPLA fonts, character sets, and math alphabets; superscripts, subscripts, underline, and italicize; and plots of the results of mathematical functions of the input data. 12 figs., 21 tabs.

Potentially hazardous test activities have historically been a part of Sandia National Labs mission to design, develop, and test new weapons systems. These test activities include high speed air drops for parachute development, sled tests for component and system level studies, multiple stage rocket experiments, and artillery firings of various projectiles. Due to the nature of Sandia's test programs, the risk associated with these activities can never be totally eliminated. However, a consistent set of policies should be available to provide guidance into the level of risk that is acceptable in these areas. This report presents a general set of guidelines for addressing safety issues related to rocket flight operations at Sandia National Laboratories. Even though the majority of this report deals primarily with rocket flight safety, these same principles could be applied to other hazardous test activities. The basic concepts of risk analysis have a wide range of applications into many of Sandia's current operations. 14 refs., 1 tab.

In this report, we examine two global energy consumption scenarios and corresponding nonenergy scenarios to determine how each will contribute to the greenhouse effect and global warming. A steady emissions trend scenario assumes only modest energy conservation and little change in the world's energy consumption patterns and nonenergy emissions. A reduced emissions trend scenario assumes significant conservation, switching from a more carbon-intensive energy source mix to a less intensive mix, and reducing nonenergy emissions. Based on the difference between the two scenarios' results, our conclusions are that it is possible to reduce global warming by over 50% using a combination of conservation and efficiency improvements, increased use of nuclear, geothermal, and solar/renewable energy sources, and reduced nonenergy emissions. 34 refs.

This report summarizes the results and conclusions generated by the US Nuclear Regulatory Commission sponsored Fire Protection Research Program at Sandia National Laboratories. Efforts conducted from the programs inception in 1975 through 1987 are discussed. The individual efforts are discussed within a framework based on specific areas of investigation. Early efforts are presented in the context of investigations of specific regulatory concerns. Later efforts are presented within the context of an integrated investigation of fire safety issues. This integrated approach considers the fire safety issue in terms of (1) source fire characterization, (2) detection and suppression system effectiveness, (3) room effects, (4) equipment response, and (5) room-to-room fire effects. The report provides a complete bibliography of reports and journal articles generated as a result of these efforts with a cross-reference listing of major reports to specific efforts. 98 refs., 23 figs., 20 tabs.

Gas holdup data for oleci acid at 291 K and for 1018 steel at 1823 K has been taken for nitrogen sparging gas. The liquid levels have been measured using a real time x-ray technique. The data have been compared to correlations from the literature to assess the appropriate correlations for use in calculating gas holdup for molten core debris in reactor accident calculations. A suitable correlation has been determined as well as coefficients for use in a drift flux model. The correlation is in the form {alpha} = 0.128 M{sup -0.0207} jg*{sup 0.584} where {alpha} is holdup, M is the Morton Number and jg* is the dimensionless gas flux through the liquid. 19 refs., 9 figs., 9 tabs.

A method to determine the dynamic shape factor of an aerosol from cascade impactor and TSI Aerodynamic Particle Sizer (APS) distribution measurements is presented and demonstrated. The response of the APS to nonspherical, porous particles is derived after the fashion of Wang and John (1987). This method does not require microscopy or chemical analytical techniques and as such is an improvement over previous methods. 37 refs., 13 figs., 1 tab.

SAVI (Systematic Analysis of Vulnerability to Intrusion) is a PC-based software package for modeling and analyzing physical protection systems. SAVI implements several features that make it a unique product. First, the user interface for site modeling and data entry is simple and flexible. Second, the SAVI model analyzes all adversary paths to the target location and, if selected, all exit paths from the target location. Third, a reference catalog and database are included that define the protection elements and safeguards components, and give detection and delay performance values for the components. Finally, SAVI's results are output in graphic form and include recommendations for upgrade.

This paper discusses the following topics: theoretical predictions of valence and conduction band offsets in III-V semiconductors; reflectance modulation of a semiconductor superlattice optical mirror; magnetoquantum oscillations of the phonon-drag thermoelectric power in quantum wells; correlation between photoluminescence line shape and device performance of p-channel strained-layer materials; control of threading dislocations in heteroepitaxial structures; improved growth of CdTe on GaAs by patterning; role of structure threading dislocations in relaxation of highly strained single-quantum-well structures; InAlAs growth optimization using reflection mass spectrometry; nonvolatile charge storage in III-V heterostructures; optically triggered thyristor switches; InAsSb strained-layer superlattice infrared detectors with high detectivities; resonant periodic gain surface-emitting semiconductor lasers; performance advantages of strained-quantum-well lasers in AlGaAs/InGaAs; optical integrated circuit for phased-array radar antenna control; and deposition and novel device fabrication from Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub y} thin films.

This report contains important information on the internationally mandated changes in the unit of the Volt and Ohm which will come into force on January 1, 1990; on how the Primary Standards Laboratory will respond to these changes, and recommendations on how the Contractor Standards Laboratories should respond to these changes. It also contains information about the new Josephson Voltage Standard that is now in operation at the Primary Standards Laboratory, and how the use of this standard will change the way that the Volt is disseminated to the Contractor Standards Laboratories. 1 fig.

EPSILON-2 is a general parallel computer architecture that combines the fine grain parallelism of dataflow computing with the sequential efficiency common to von Neumann computing. Instruction level synchronization, single cycle context switches, and RISC-like sequential efficiency are all supported in EPSILON-2. The general parallel computing model of EPSILON-2 is described, followed by a description of the processing element architecture. A sample code is presented in detail, and the progress of the physical implementation discussed. 11 refs., 14 figs.

In the radiation-hardened, optically triggered thyristor development being carried out jointly by Organizations 1141 and 2531, a theoretical model was needed to assist in designing the devices. This model had to accurately predict thyristor performance (e.g., breakover voltage and holding current) for different fabrication and experimental parameters such as doping, layer thickness, temperature, and incident optical intensity. This report describes a mode we are currently developing that is based on treating a p-n-p-n thyristor as coupled p-n-p and n-p-n transistors. This approach has the advantages of providing tractability of the physics that govern thyristor behavior without requiring extensive numerical computations. When benchmarked by a more rigorous (and, consequently, computationally more complicated) treatment, our model should provide accurate and fast screening of a wide range of thyristor configurations. Section 2 describes the general thyristor configuration we wish to investigate. The derivation of the basic equations for our thyristor model is presented in Sections 3. These equations depends on the saturation currents and multiplication factors at each p-n junction, and on the current gains of p-n-p and n-p-n transistors.

The High Temperature Borehole Televiewer is a downhole instrument which provides acoustic pictures of the borehole walls that are suitable for casing inspection and fracture detection in geothermal wells. The Geothermal Drilling Organization has funded the development of a commercial tool survivable to temperatures of 275{degree}C and pressures of 5000 psi. A real-time display on an IBM-compatible PC was included as part of the development effort. This report contains a User Manual which describes the operation of this software. The software is designed in a menu format allowing the user to change many of the parameters which control both the acquisition and the display of the Televiewer data. An internal data acquisition card digitizes the waveform from the tool at a rate of 100,000 samples per second. The data from the tool, both the range or arrival time and the amplitude of the return signal, are displayed in color on the CRT screen of the computer during the logging operation. This data may be stored on the hard disk for later display and analysis. The software incorporates many features which aid in the setup of the tool for proper operation. These features include displaying and storing the captured waveform data to check the voltage and time windows selected by the user. 17 refs., 28 figs., 15 tabs.

Multi-dimensional radiative transfer in combined mode heat transfer problems was investigated with emphasis on the analysis and characterization of a free-falling particle cloud, direct absorption solar central receiver. A model was developed to calculate the relevant distributions in the curtain while a concentrated solar beam is impinging on the front face of the medium. The discrete ordinated approximation was applied to allow the spectral equation of transfer (EOT) to be modeled as a PDE. Model verification tests were conducted to determine the accuracy of the model. One- and two-dimensional results showed that the discrete ordinates model provides satisfactory estimates of the radiant intensity, the heat flux and the temperature distributions for ordinate sets above S{sub 4} (12-flux approximation) for both the black and gray cases. 75 refs., 69 figs., 13 tabs.

This report describes the results of tests conducted on three different designs of full-size electrical penetration assemblies (EPAs) that are used in the containment buildings of nuclear power plants. The objective of the tests was to evaluate the behavior of the EPAs under simulated severe accident conditions using steam at elevated temperature and pressure. Leakage, temperature, and cable insulation resistance were monitored throughout the tests. Nuclear-qualified EPAs were produced from D. G. O'Brien, Westinghouse, and Conax. Severe-accident-sequence analysis was used to generate the severe accident conditions (SAC) for a large dry pressurized-water reactor (PWR), a boiling-water reactor (BWR) Mark I drywell, and a BWR Mark III wetwell. Based on a survey conducted by Sandia, each EPA was matched with the severe accident conditions for a specific reactor type. This included the type of containment that a particular EPA design was used in most frequently. Thus, the D. G. O'Brien EPA was chosen for the PWR SAC test, the Westinghouse was chosen for the Mark III test, and the Conax was chosen for the Mark I test. The EPAs were radiation and thermal aged to simulate the effects of a 40-year service life and loss-of-coolant accident (LOCA) before the SAC tests were conducted. The design, test preparations, conduct of the severe accident test, experimental results, posttest observations, and conclusions about the integrity and electrical performance of each EPA tested in this program are described in this report. In general, the leak integrity of the EPAs tested in this program was not compromised by severe accident loads. However, there was significant degradation in the insulation resistance of the cables, which could affect the electrical performance of equipment and devices inside containment at some point during the progression of a severe accident. 10 refs., 165 figs., 16 tabs.

The Primary Standards Laboratory (PSL) operates a system-wide primary standards and calibration metrology program for the US Department of Energy, Albuquerque Operations Office (DOE/AL). The PSL mission is to develop and maintain primary standards; to calibrate electrical, physical, and radiation reference standards for member laboratories (DOE/AL integrated contractors); to conduct technical surveys and audits of these laboratories; and to recommend and implement system-wide improvements. This report summarizes activities of the PSL for the first half of 1989 and provides information pertinent to the operation of the DOE/AL Standards and Calibration Program. Specific areas covered include development projects, calibration and special measurements, surveys and audits, and significant events. Appendixes cover certifications and reports, commercial calibration laboratories, PSL memoranda, National Bureau of Standards (NBS)/National Institute of Standards and Technology (NIST) test numbers, and a DOE standards and calibration memorandum.

The connector selection program is a database application that allows engineers to locate information about connectors that meet their requirements. This document describes the design and implementation of the database, the data input application, and the user interface. Nijssen's Information Analysis Methodology (NIAM) was used to characterize the connector data requirements which yielded the database design. This design was transformed into database record structures that were implemented in the relational database management software ORACLE. After the database was in place, data input screens were created to capture the connector data, analyze it, and place it in the proper database record structures. Finally, a user interface was designed and developed that displays or prints the information contained in the database, associated drawings, and documentation related to the program and its data.

Proto II is a nominal 8 terawatt pulsed accelerator which is available for x-ray effects testing. The purpose of this guide is to serve as a basic source of information for prospective users of Proto II. Enclosed is a discussion of the design and operation of the accelerator and a summary of x-ray environmental data. The guide also contains a description of experimental support facilities, data acquisition and analysis systems and general information for users. 4 refs., 22 figs., 5 tabs.

Sandia National Laboratories, under the sponsorship of the United States Nuclear Regulatory Commission, is currently developing test validated methods to predict the pressure capacity of light water reactor containment buildings when subjected to postulated severe accident conditions. These conditions are well beyond the design basis. Scale model tests of steel and reinforced concrete containments have been conducted as well as tests of typical containment penetrations. As a part of this effort, a series of tests was recently conducted to determine the leakage behavior of inflatable seals. These seals are used to prevent leakage around personnel and escape lock doors of some containments. The results of the inflatable seals tests are the subject of this report. Inflatable seals were tested at both room temperature and at elevated temperatures representative of postulated severe accident conditions. Both aged (radiation and thermal) and unaged seals were included in the test program. The internal seal pressure at the beginning of each test was varied to cover the range of seal pressures actually used in containments. For each seal pressure level, the external (containment) pressure was increased until significant leakage past the seals was observed. Parameters that were monitored and recorded during the tests were the internal seal pressure, chamber pressure, leakage past the seals, and temperature of the test chamber and fixture to which the seals were attached. 8 refs., 34 figs., 7 tabs.

An exact solution is derived for one-dimensional radionuclide transport under time-varying fluid-flow conditions including radioactive decay but with the approximation that all radionuclides have identical retardation factors. The solution is used to obtain exact expressions for the cumulative radionuclide mass transported past a fixed point in space over a given time period, and to assess the effects of a periodic perturbation and a step change on the fluid-flow velocity and dispersion coefficient. 14 refs., 3 figs., 3 tabs.

Sandia National Laboratories, in conjunction with the Department of Energy Computer Integrated Manufacturing Program, supports the use of the Department of Energy Data Exchange Format (DOEDEF) subset of IGES (the Initial Graphics Exchange Specification) for exchanges of mechanical product definition data between dissimilar computer aided systems of various types. The background for this position is described here.

This report summarizes about 1260 tests performed on small threaded fasteners (equal to or less than 1/4 inch in diameter and designated as 1/4-20 UNC, {number sign}4-40 UNC, {number sign}2-56 UNC, and 1.0 UNM). Tests determined the tensile strengths of the screws, the lengths of engagement needed to develop the full tensile strengths when the screws were engaged in 6061-T6 Aluminum, Hiperco 50, and 303 Stainless Steel, and whether relationships existed between the tensile strengths and Knoop Micro-Hardness measurements taken on the threaded ends of the screws. 17 figs., 13 tabs.

We studied the sintering behavior of high field chem-prep ZnO varistors using dilatometry and determined how sintering conditions influence the varistor's electrical properties. The dilatometric results indicated that 95% theoretical densities could be obtained with a soak time of only 0.5 hour above 752{degree}C, using a 3{degree}C/min ramp rate; greater shrinkage did not occur for soak temperatures above 752{degree}C. A variety of soak times and temperatures was found to be capable of producing varistors with acceptable electrical properties. The variation in the switching field, E{sub s} (at a current density of 10 A/cm{sup 2}), with soak temperature was found to be significantly less for short soak times than for the standard 16 hour soak time. Annealing sintered pellets at 700{degree}C for 4 hours raised the nonlinearity coefficients by {approximately}25% and decreased E{sub s} by {approximately}10%. This uniform decrease in E{sub s} led to a further reduction in the slope of E{sub s} vs soak temperature for values of E{sub s} in the specified range of interest. Further testing of more samples, of samples from different powder batches, and of samples annealed at various temperatures needs to be performed to verify these results. 19 refs., 10 figs., 1 tab.

A 1:6-scale model of a reinforced concrete containment building was pressurized incrementally to failure at a remote site at Sandia National Laboratories. The response of the model was recorded with more than 1000 channels of data (primarily strain and displacement measurements) at 37 discrete pressure levels. The primary objective of this test was to generate data that could be used to validate methods for predicting the performance of containment buildings subject to loads beyond their design basis. Extensive analyses were conducted before the test to predict the behavior of the model. Ten organizations in Europe and the US conducted independent analyses of the model and contributed to a report on the pretest predictions. Predictions included structural response at certain predetermined locations in the model as well as capacity and failure mode. This report discusses comparisons between the pretest predictions and the experimental results. Posttest evaluations that were conducted to provide additional insight into the model behavior are also described. The significance of the analysis and testing of the 1:6-scale model to performance evaluations of actual containments subject to beyond design basis loads is also discussed. 70 refs., 428 figs., 24 tabs.

In this report we describe the development of an unconventional fabrication process using traditional printed-circuit-board materials for assembly into a geophysical electrical simulator. This simulator serves as a bench top geophysical electrical simulation facility for studying and validating dc and very-low-frequency geophysical responses of interest in geologic formations. Soft copper sheet was laminated to glass/epoxy prepreg, without the use of brown oxide coating or any other adhesion promoter, to form a triangle of compound curvature. These triangles were instrumented by the Advanced Process Technology Division and were then assembled into the final hemisphere by the Organic Materials Division. The back side of the hemisphere assembly was encapsulated in polyurethane foam to provide a rigid structure. 1 ref., 10 figs.

A series of shock-loading experiments on an energetic propellant and its simulant was conducted on a light-gas gun. The purpose of this work was to characterize the shock sensitivity of WAK-2, which is a composite-modified, double-based, booster-rocket propellant and its simulant UGS. The initial objectives were to obtain Hugoniot data, to investigate the pressure threshold at which a reaction occurs, and to measure spall threshold at various impact velocities. The Hugoniot data obtained for the propellant fits the Hugoniot curve provided by the manufacturer of the propellant. A Hugoniot curve developed for the simulant was found to match that of the propellant. The initial density, {rho}{sub 0}, initial bulk sound velocity, C{sub 0}, and constant S values for the energetic propellant WAK-2 and its simulant UGS were 1.85 g/cm{sup 3}, 2.2 mm/{mu}s and 2.66, respectively. The ignition threshold pressure of the WAK-2 was found to be in the range of 3 kbar. A violent reaction was observed for a sample impacted at a pressure of 22 kbar. In spall tests, impact pressures in the range of 1.1 to 3.1 kbar were applied to the propellant/simulant. The propellant exhibited spall strengths {approximately}0.33 kbar, with its simulant being somewhat weaker, {approximately}0.22 kbar. Scanning electron microscopy and electron microprobe analysis were used to characterize the microstructures of the materials and to determine the details of the spall events. 20 refs., 19 figs., 9 tabs.

CEPXS is a multigroup-Legendre cross-section generating code. The multigroup-Legendre cross sections produced by CEPXS enable coupled electron-photon transport calculations to be performed with the one-dimensional discrete ordinates code, ONEDANT. We recommend that the 1989 version of ONEDANT that contains linear-discontinuous spatial differencing and S2 synthetic acceleration be used for such calculations. CEPXS/ONEDANT effectively solves the Boltzmann-CSD transport equation for electrons and the Boltzmann transport equation for photons over the energy range from 100 MeV to 1.0 keV. The continuous slowing-down approximation is used for those electron interactions that result in small-energy losses. The extended transport correction is applied to the forward-peaked elastic scattering cross section for electrons. A standard multigroup-Legendre treatment is used for the other coupled electron-photon cross sections. CEPXS extracts electron cross-section information from the DATAPAC data set and photon cross-section information from Biggs-Lighthill data. The model that is used for ionization/relaxation in CEPXS is essentially the same as that employed in ITS. 43 refs., 8 figs.

Simple mixture rules are used to calculate input parameters for an analytic equation of state package (ANEOS) to model saturated limestone as a homogeneous material. This method is used to determine changes in material parameters as the volume fraction of water in the rock changes. Hugoniots determined from these are compared with experimental and theoretical Hugoniots for saturated limestone samples with various porosity levels. Ground shock calculations are also performed to model a deeply buried 500 kiloton explosion in saturated limestone containing various amounts of water. 37 refs., 29 figs.

The Data Retention Chassis (DRC) is a data acquisition component based on the Motorola 68000 microprocessor. The purpose of the DRC is to download the correct set-up parameters into sixteen Tektronix 7912 digitizers, to verify that the digitizers retain their settings, and (once the digitizers have triggered) to load that data into the DRC battery back-up CMOS memory. The DRC also has a circuit built into it called the COMMAND LINK. With the help of the TA698 Alternate Common Equipment (ACE), the user employs this link to communicate interactively with the digitizers and the DRC. Another circuit built into the DRC is the data stream multiplexer (DSM) for high-speed data transfers.

A boundary layer theory for the flow of power-law fluids in a converging planar channel has been developed. This theory suggests a Reynolds number for such flows, and following numerical integration, a boundary layer thickness. This boundary layer thickness has been used in the generation of a finite element mesh for the finite element code FIDAP. FIDAP was then used to simulate the flow of power-law fluids through a converging channel. Comparison of the analytic and finite element results shows the two to be in very good agreement in regions where entrance and exit effects (not considered in the boundary layer theory) can be neglected. 6 refs., 8 figs., 1 tab.

Sandia National Laboratories, Albuquerque, has been designated as Lead Center for the Exploratory Battery Technology Development and Testing Project, which is sponsored by the US Department of Energy's Office of Energy Storage and Distribution. In this capacity, Sandia is responsible for the engineering development of advanced rechargeable batteries for both mobile and stationary energy storage applications. This report details the technical achievements realized in pursuit of the Lead Center's goals during calendar year 1988.

To provide the assurance that a newly developed system meets customer requirements, certification testing of the system must be performed. The MIVS Program Plan required the generation of a Certification Test Plan, detailing the necessary steps required to certify the performance, reliability and quality of the MIVS. This report explains the results of the multi-element environmental testing, of the safety tests performed on the units, and the mechanical shock and random vibrations tests. 3 figs.

The Modular Integrated Video System (MIVS) was developed to provide a replacement surveillance system for the IAEA's Twin Minolta Film Camera System. This task was sponsored by the Department of Energy (DOE) and the US Program for Technical Assistance to IAEA Safeguards (POTAS). This is the final report describing the development, testing, and production of the MIVS. It begins with the generation of a Program Plan identifying the principal steps necessary for the development of a highly reliable, quality surveillance system. Among these steps were the generation of the functional specifications and the certification test plan. These documents describe prototype development and demonstration, Class III production, environmental testing, reliability testing, field commissioning, and commercial manufacturer selection. Data accumulated from the various steps of the Program Plan are presented in this final report. 10 figs.