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.
The US Department of Energy (DOE) has supported the development of the sodium-sulfur technology since 1973. The programs have focused on progressing core aspects of the technology and completing initial battery engineering for both mobile and stationary applications. An overview of the Office of Energy Management (OEM) activities is contained in this paper. Two major development programs have been active: the first with Ford Aerospace and Communications Corporation (1975 to 1985), and the second with Chloride Silent Power Limited (1985 to 1990). With the completion this year of the qualification of a cell suitable for initial Solar Energy Systems (SES) applications, the emphasis of future DOE/OEM sodium/sulfur programs will shift to SES-battery engineering and development. The initial effort will resolve a number of issues related to the feasibility of utilizing the sodium/sulfur technology in these large-scale applications. This multi-year activity will represent the initial phase of an integrated long-term DOE-supported program to produce a commercially viable battery system.
The integrity of many mechanical assemblies and electrical components depends on small threaded fasteners. The design standards for small (less than {1/4} inch in diameter) screws made of stainless steel are not as well developed as those for larger sizes of high strength steels. The typical design approach is based on the application of static design principals. Steady state accelerations are applied to the component or assembly and sufficient screws are installed in mounting hardware for attachment to the next assembly. These design principals have been used successfully for years in a wide variety of applications. As the parts requiring small screws have continued to decrease in size, some design requirements include greater thread depths and adherence to strict interpretation of the governing thread standards. These design requirements have their origins in the lack of adequate definitions and standards for designs using small threaded fasteners. These design practices have led to significant problems in manufacturing parts with small threaded fasteners by requiring thread depths to four and more diameters of engagement while maintaining thread heights (radial engagement) of 75 percent throughout the thread interfaces. A test program was developed to address questions regarding design and manufacturing issues involving small threaded fasteners which included tensile strength, length of engagement needed to achieve the full strengths of the screws, and verification of the static design principals in dynamic conditions. This paper summarizes the initial results obtained to date from this test program and describes the work-in-progress on the dynamic tests with their related static tests. 2 refs., 4 figs., 4 tabs.
An isotropic continuum damage theory which accounts for the degradation of material strength under quasi-static loading conditions has been developed in the present investigation. The damage mechanism in this theory has been selected to be the interaction and growth of subscale cracks. The development of the theory follows closely the strain-rate dependent dynamic model advanced by the first author and his coworkers. Briefly, the cracks are activated by the maximum principal tensile strain and the density of activated cracks is described by a Weibull statistical distribution. The moduli of a cracked solid derived by Budiansky and O'Connell are then used to represent the global material degradation due to subscale cracking. Two additional material constants have been introduced in this model. These constants are determined from uniaxial tensile test data. The model has been implemented into a finite element code. Sample calculations involving the uniaxial and biaxial responses of plain concrete panels are presented to demonstrate the utility of the model. 7 refs., 2 figs.
The first in a series of multi-factor experiments designed to optimize the chemical cleaning procedure for four types of silicon material used in solar cell fabrication has been completed. The goal of this first experiment (a twenty-two factor main-effects experiment) was to determine the factors associated with chemical cleaning procedures that are most important in obtaining high excess charge-carrier recombination lifetime following a high-temperature furnace oxidation. It was determined that the factors having the strongest influence on charge-carrier lifetime were different for the four different silicon materials considered. In general, the lower the lifetime of the material, the less sensitive the material was to different chemical cleaning steps. The stability of the lifetime was also evaluated with several factors exhibiting a significant effect for high-quality silicon. Chemical cleaning procedures were identified that resulted in stable post-oxidation lifetimes greater than 2 ms for high-resistivity float-zone silicon. 3 refs., 8 figs.
Insulations are used in metallic glass ribbon cores in pulse power applications to prevent interlaminar eddy currents due to voltages induced between adjacent laminations. These interlaminar eddy currents can greatly increase the losses in cores, and, thereby, decrease the pulse permeability at high magnetization rates. This paper reports results of experiments with various insulation materials and both low and high induced anisotropy energy iron-base metallic glass ribbons. Co-wound insulation films as well as conformal insulations were investigated. Magnetic properties and voltage hold-off strengths are reported. 11 refs., 11 figs., 5 tabs.
When quartz controlled oscillators are required for use in applications demanding precision many factors will ultimately place limitations on the ability of the oscillator to remain at the desired frequency. These factors include temperature, resonator Q, pullability, radiation, output load variability, and the electronic components. This paper addresses the subject of frequency instability of oscillator circuits due to power supply voltage variations. In particular, the primary sources of this instability are described for a Pierce oscillator employing a bipolar transistor and design techniques are presented which minimize these frequency pulling effects. 4 refs., 17 figs.
The three-dimensional structural analysis of reentry vehicles presents a considerable challenge to the analyst. This is due to the mechanics of the problem as well as the incorporation of results from several disciplines into the environmental description of the problem. Separate results from aero-analyses, frequently computed in one-dimensional format must be combined into a three-dimensional format suitable for a structural finite element analysis. Features required for the analysis include the ablated thickness of the heatshield structure, as well as pressure on the vehicle and the temperature distribution through the heatshield. By combining these environments, a complete description of all factors which affect the structural performance of reentry vehicles are included into one analysis. This paper presents a method of analyzing the structural response of reentry vehicles using the complete three-dimensional environmental load description.
Reflection Mass Spectrometry (REMS) consists of a cryo-shrouded mass spectrometer which measures mass-analyzed, line-of-sight chemical fluxes from a growing wafer. It is especially useful during III/V molecular beam epitaxy (MBE) for which there are always substantial group V fluxes and often some group III fluxes leaving the wafer during growth. These fluxes depend sensitively on the instantaneous chemical reactivity of the surface. That chemical reactivity in turn depends on instantaneous alloy composition (III/III ratio), surface stoichiometry (As coverage) and temperature. In this brief summary of our work, we describe two examples of the engineering'' usefulness of REMS, involving MBE of InAlAs and InGaAs and one example of measurements of basic scientific interest. 3 figs.
A program is under way to develop liquid metal heat pipes that can transfer energy from the focal point of a parabolic solar concentrator to the heater tubes of one or more Stirling engines. To design high performance wicks for heat pipe solar receivers, it is necessary to have an accurate assessment of the wick's properties. Procedures for measuring the flow properties of wicks before and after fabrication processes take place are presented. The testing procedures provide a useful method of determining the validity of a wick design before full-scale testing is attempted.
Significant progress is continuing 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 we are likely to see more in the near future. This paper describes the most significant developments of the last two years, including descriptions of PV concentrator module development and reliability activities, advances in concentrator cell technology, the new PV concentrator array installations, a new Concentrator Initiative Program, and results of the latest costing study. 26 refs., 9 figs., 1 tab.
Chacahoula salt dome, eight miles southwest of Thibodaux, LA, could be solution mined to create caverns for storing as much as 500 million barrels (MMB) of crude oil, should the Strategic Petroleum Reserve (SPR) require additional storage volume. The salt mass geometry is confirmed by more than 50 oil wells, and also from previous exploratory drilling for sulphur. Top of salt occurs at {minus}1100 ft, and some 1300 acres exist within the {minus}2000 ft salt contour. Frasch mining of 1.35 million long tons of sulphur caused the surface to subside about one foot on the northeastern part of the dome. Creep-induced subsidence averaging {approximately}2.7 ft over 30 yrs is estimated for a 200 MMB cavern array, which would require perimeter diking to control localized perennial flooding. Earthquakes approaching intensity MM 6 have occurred nearby and are expected to recur on the order of {approximately}100 yrs but would not affect cavern stability. Additional study of brine disposal methods and hurricane surge probabilities are needed to establish design parameters and cost estimates for storage. 11 refs., 8 figs., 2 tabs.
A Nuisance Alarm Data System (NADS) was developed to gather long- term background alarm data on exterior intrusion detectors as part of their evaluation. Since nuisance alarms play an important part in the selection of intrusion detectors for use at Department of Energy (DOE) facilities, an economical and reliable way to monitor and record there alarms was needed. NADS consists of an IBM Personal Computer and printer along with other commercial units to communicate with detectors, to gather weather data and to record video for assessment. Each alarm, its assessment and the weather conditions occurring at alarm time are placed into a database that is used in the evaluation of the detector. The operating software is written in Turbo Pascal for easy maintenance and modification. A portable system, based on the NADS design, has been built and shipped to other DOE locations to do on-site alarm monitoring. This has been valuable for the comparison of different detectors in the on-site environment and for testing new detectors when the appropriate conditions do not exist or cannot be simulated at the Exterior Intrusion Detection Testbed.
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.
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.
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.
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 molten salt cavity receiver was solar tested at Sandia National Laboratories during a year-long test program. Upon completion of testing, an analysis was performed to determine the effect of thermal cycling on the receiver. The results indicate substantial fatigue damage accumulation for the receiver when the relatively short test time is considered. This paper describes the methodology used to analyze the cycling, the results, and how they affect future receiver design. The test receiver was configured as a C-shaped cavity with eight multipass heat absorption panels. The tubes were Alloy 800. The heat exchange medium was a molten nitrate salt mixture (60% sodium nitrate, 40% potassium nitrate by weight). The operating temperature range was from 288°C to 566°C.
A sodium reflux pool-boiler solar receiver has been tested on a nominal 75-kWt 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 advantages over directly illuminated tube receivers. The advantages include more uniform temperature, which results in longer lifetime and higher temperature available to the engine. The absorber was a 70° half-angle spherical segment with an 8.63 inches radius, positioned behind an 8.65 inches diameter aperture. The relatively small size of this receiver, which minimized thermal losses, fabrication costs, and sodium inventory, was possible because of its excellent internal heat transfer characteristics. Tests were run at sodium temperatures up to 800°C and receiver input power levels as high as 67 kWt. At maximum input power, the peak in the solar flux distribution on the absorber was calculated to be 73 Wt/cm2. Receiver efficiency was about 90% when the input power and sodium temperature were at their maximum values. To promote stable boiling, the receiver design included 35 equally spaced artificial cavities in the absorber wetted surface. In all tests, stable boiling was always observed. Under certain conditions during both real and simulated cloud transients, high incipient boiling superheats were observed. This behavior could be suppressed either actively by momentarily increasing the thermal load on the receiver or passively by the addition of a small amount of xenon into the boiler.
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.
Under compressive stresses, brittle polycrystalline materials fail as the result of the growth, interaction and coalesence of microcracks. To predict the deformation of damaging material, constitutive laws developed for such materials must incorporate the effects of crack size, density, orientation, and interaction.A method of incorporating the accumulation and growth of microcracks into a continuum model is to use a measure of microcrack growth and interaction defined as damage. Although a number of damage theories have been proposed, there is no generally accepted experimental technique for detecting and measuring damage. Acoustic emissions (AE) have been correlated with microcrack nucleation and growth. We propose that AE locations and density are useful measures of damage that can be correlated with calculated damage. Our approach is to use acoustic emissions (AE) and computer modeling to study the development of damage in geomaterials.
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.
Consideration is given to the problem of stabilizing a plant using a suboptimal stable compensator of fixed order. The resulting equations are a modified form of the optimal projection equations, with the separation principle not holding in either the full- or reduced-order case. An overbounding technique on the state covariance guarantees that the compensator is stable if nonnegative definite solutions exist to the design equations.
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.
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 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.
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.
American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
Priddy, T.G.
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.
American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED
O'Hern, T.J.; Rader, D.J.; Ceman, D.L.
The Phase Doppler Particle Analyzer (PDPA) is an LDV-based instrument for simultaneous measurement of single particle size and velocity. A PDPA calibration was performed using well-characterized liquid droplets in the 4 to 80 μm diameter range. Two test liquids were used: oleic acid and kerosone. A standard PDPA instrument and a fiber-optic probe PDPA system were tested. The standard instrument measurements agreed with expected droplet diameters to within the droplet generation accuracy for droplets above 15 μm diameter, and had a measurement accuracy of about 2 μm for smaller droplets.
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.
Proceedings - Electronic Components and Technology Conference
Frear, D.R.
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.
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.
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.
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.
This document evaluates the accuracy of mass properties computations from the ANVIL 5000 CAD system. Mass property results and a measure of their accuracy are given for both individual solid model components and for point-mass assembly sums. The mass properties' accuracies were determined by comparing the results obtained from ANVIL 5000 with either theoretical values or with results from another trusted software package.
The SA3124 is a silicon zener diode designated as a JANTXV1N965B-1 device manufactured by Microsemi of Scottsdale, Arizona. The devices were procured from Microsemi and tested by the Design Agency in accordance with PS319094. The SA3124 is a 15V zener diode packaged in a DO-35 cylindrical lead silicate glass package. The monolithic silicon die is sandwiched between two copper-clad Dumet plugs wth coaxial copper-clad and tin-dipped iron leads welded to them. 11 figs., 3 tabs.
The SA3274-1 and SA3274-2 are bi-directional transient voltage suppressors that have a nominal breakdown voltage of 12 Volts and 22 Volts, respectively. These devices are packaged in an axial-leaded cylindrical glass package. These devices were manufactured by and procured from Microsemi Corporation in Santa Ana, California. They were tested by the Design Agency in accordance with PS319848. 25 figs.
An approach for initiating tracks for multiple target tracking is presented. A means of using a graph to represent objects moving in a sequence of images is given. The approach for initiating tracks is based on a dynamic programming algorithm for finding the shortest path in the graph. For comparison purposes an extensive optimal solution and other practical track initiation approaches from the open literature are discussed. 7 refs., 7 figs.
A Seismic Signal Modeling software package has been implemented for the RSTN and the NORESS/ARCESS data. The key features of the software are: (1) It removes over a limited band the gain and phase effects that were introduced by the seismometer and its associated filters. This removal was accomplished by using Finite Impulse Response (FIR) filter techniques to produce a resulting signal in terms of either ground-motion velocity or displacement. (2) It combines two separate bands of data, which are sampled at different rates, into a single broadband signal. (3) It produces a time-domain plot of the signals. (4) It produces a spectral analysis of the signals, including signal-to-noise ratio and comparison of the signals. 5 refs., 22 figs., 3 tabs.
A set of 6-ft-diameter ribbon parachutes (geometric porosities of 7%, 15%, and 30%) was tested in various subsonic wind tunnels covering a range of geometric blockages from 2% to 35%. Drag, base pressure, and inflated geometry were measured under full-open, steady-flow conditions. The result drag areas and pressure coefficients were correlated with the bluff-body blockage parameter (i.e., drag area divided by tunnel cross-sectional area) according to the blockage theory of Maskell. The data show that the Maskell theory provides a simple, accurate correction for the effective increase in dynamic pressure caused by wall constraint for both single parachutes and clusters. For single parachutes, the empirically derived blockage factor K{sub M} has the value of 1.85, independent of canopy porosity. Derived values of K{sub M} for two- and three-parachute clusters are 1.35 and 1.59, respectively. Based on the photometric data, there was no deformation of the inflated shape of the single parachutes up to a geometric blockage of 22%. In the case of the three-parachute cluster, decreases in both the inflated diameter and the spacing among member parachutes were observed at a geometric blockage of 35%. 11 refs., 9 figs., 3 tabs.
Waypoint guidance is a technique used to steer an autonomous vehicle along a desired course. Waypoints are designated at intervals along that course. The guidance algorithms issue steering commands that, if followed, result in the vehicle's traveling from waypoint to waypoint. Thus, the vehicle remains on or very close to the desired trajectory. Waypoints can be specified by latitude, longitude, and altitude in geographic coordinates. The vehicle's current location can be described similarly. This is enough information to determine the direction of travel that would take the vehicle to the waypoint. The shortest route from one point on a spherical surface to another on the same surface is a great circle. A great circle lies in a plane that contains the center of the sphere. The plane also is normal to the surface of the sphere along the great circle. The earth actually is distorted slightly from spherical; it is ellipsoidal. An ellipsoidal earth model will be used in this report. Features of the great circle will be applied to effect good approximations of shortest routes to waypoints. Therefore, only the endpoints of long, straight course segments need be specified. 5 figs.
Drillstem tests, slug tests, a small-scale pumping test, and a large-scale pumping test of the Culebra Dolomite Member of the Rustler Formation were performed in 1988 at the H-11 hydropad at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. The drillstem, slug, and small-scale pumping tests were conducted in well H-11b4 to evaluate well and aquifer properties in preparation for a tracer test. The large-scale pumping test, known as the H-11 multipad test, was performed by pumping well H-11b1 in the southern part of the WIPP site at a rate of six gpm for 63 days and monitoring drawdown and recovery responses in three other wells on the H-11 hydropad and at 11 observation wells within a three-mile radius. Responses were observed in 10 of these distant wells. The H-11 multipad pumping test complemented the H-3 and WIPP-13 multipad pumping tests conducted in the central and northern portions of the WIPP site in late 1985 and early 1987, respectively. 67 refs., 124 figs., 31 tabs.
The formation of pristine silica fiber sections in an ultra high vacuum environment requires the critical control of production parameters. Glass temperature and fiber draw force must be precisely controlled to produce favorable results. Process control is achieved by automating the operation of a high power CO{sub 2} laser and the acquisition of data with a dedicated microprocessor. This combination, with the integration of ocular control through the application of digital image processing techniques, has subsequently led to a consistent and reproducible means of forming high quality pristine glass fiber test sections on the order of 25 {mu}m to 50{mu}m in diameter. Fibers formed in this manner are tested to failure (in situ) by applying loads at various rates in controlled environments. This report presents the techniques and devices used to develop this automated fabrication and testing system. 2 refs., 5 figs.
The phase gradient algorithm represents a powerful new signal processing technique with applications to aperture synthesis imaging. These include, for example, synthetic aperture radar phase correction and stellar image reconstruction. The algorithm combines redundant information present in the data to arrive at an estimate of the phase derivative. In this report, we show that the estimator is in fact a linear, minimum variance estimator of the phase derivative. 7 refs.
The quasi-static failure criteria, elastic constants, and p-wave velocities have been determined for a granite and a sandstone in which blasting experiments are being carried out by the Advanced Technology Division (6258). In addition, the dynamic strength of the granite was measured using a Kolsky bar. Both rocks show a linear increase in strength with increasing confining pressure. The dynamic strength of the granite is as much as 330% greater than the quasi-static value. The strength of the granite was also dependent on the angle between the foliation and the loading direction. There was a 20% difference in the p-wave velocity between that measured parallel to and perpendicular to the bedding in the sandstone. 4 refs., 4 figs., 5 tabs.
Blow-by is a common occurrence in two-stage light gas guns. Although the blow-by is often inconsequential, it can sometimes present a serious problem. Various projectile designs have been tried to prevent blow-by, and a successful design is described. Computer calculations which clarify the dynamic performance of the design are presented, along with a parameter variation study to indicate the sensitivity of the design to certain geometric parameters. 6 refs., 12 figs., 1 tab.
The LIFE2 computer code is a fatigue/fracture analysis code specifically designed for the analysis of wind turbine components. It is a PC-compatible Fortran code that is written in a top-down modular format. In this numerical formulation, an S-n'' fatigue analysis is used to describe the initiation, growth and coalescence of micro-cracks into macro-cracks. A linear, da/dn'' fracture analysis is used to describe the growth of a macro-crack. This paper presents the numerical formulations used to implement these analyses. 16 refs., 2 tabs.
LIFE2 is a PC-compatible computer code that analyzes the service lifetime of a WECS component. The LIFE2 code is written in Fortran and has the option of using either a fatigue analysis or a linear fracture mechanics analysis. This document contains information on what the code expects as input and what can be expected as output from the code. Also included are two example problems. 11 refs., 9 figs., 1 tab.
Thermal testing of space payloads at Sandia National Laboratories is conducted in a large cylindrical (7.0 feet in diameter) vacuum chamber with temperature controlled walls. The payload is generally attached to a baseplate with independent temperature controls. To establish well-defined boundary conditions during the tests, uniform wall temperatures are desired in the test chamber. Thermal-vacuum tests were conducted on this space simulation chamber to determine if temperature gradients existed on the chamber shroud and end-bells. Recorded temperature measurements indicated large temperature gradients on the chamber shroud and end-bells. Furthermore, it was difficult to manually control the flow of liquid to the end-bells in order to achieve equal end-bell temperatures. However, results from these tests were used in a computer program developed to predict locations on the shroud and end-balls where a thermocouple would measure the best area-weighted average temperature. These measurements provide necessary boundary temperatures that can be used in a thermal model of a satellite payload. Results were obtained for different shroud and baseplate temperature settings. 8 figs., 5 tabs.
This report summarizes the progress of the Borehole Directional Radar (BDR) System, which is a high-power, high-resolution tool that is being developed to locate lithologic layers or fractures away from a wellbore. The key to the tool's potential is its ability to accurately measure distance and direction of a lithologic discontinuity underground. The results of two field tests in 1988 are presented. The report also discusses the deficiencies of the current system, and a proposed upgrade. Finally, possible other applications of the BDR System are outlined, including (1) locating gas and oil reservoirs below a salt dome, (2) determining the integrity of underground structures (e.g., Strategic Petroleum Reserve, Nuclear Waste Repository Site), and (3) verifying underground nuclear tests. 25 refs., 14 figs.
A computer code is described which is designed to determine the fraction of time during which a given ground location is observable from one or more members of a satellite constellation in earth orbit. Ground visibility parameters are determined from the orientation and strength of an appropriate ionized cylinder (used to simulate a beam experiment) at the selected location. Satellite orbits are computed in a simplified two-body approximation computation. A variety of printed and graphical outputs is provided. 9 refs., 50 figs., 2 tabs.
An algorithm and a computer program are described for use in determining the geographic locations common between the orbit paths of two satellites or between different portions of a single satellite's orbital path. The method selected uses semi-inertial geometric constructions to determine the crossing locations. 6 refs.
The uniaxial compressive strength of air-dry and water-saturated ashfall tuff from the Nevada Test Site was measured as a function of strain rate from 10{sup {minus}6} to 10{sup 3} s{sup {minus}1}. Two different testing devices were used to achieve this wide range in rate, an electro-hydraulic, servo-controlled load frame, and a Kolsky bar. Critical strain rates of 82 s{sup {minus}1} and 22{sup {minus}1} were found for dry and saturated tuffs, respectively. Below the critical rate the strength is a weak function of strain rate and above the critical rate strength varies as the cube root of strain rate. The strengths of the dry and saturated tuff are the same above the critical rate. At slower rates, the saturated tuff is weaker at all rates and shows a slightly stronger strain-rate sensitivity. 26 refs., 5 figs.
A knowledge based computer program that assists programmers of Numerically Controlled (NC) machine tools is described. The program uses part features identified by the NC programmer at a CAD/CAM graphics display and a set of manufacturing rules to select machining parameters and produce NC part programs. An expert system determines the correct NC sequence and the machining parameters. Both milled and point-to-point features are programmed by the Milling Assistant. Examples are included to illustrate the problem domain. Extensions to the Milling Assistant are described. 11 refs.
Various models of steam explosion triggering and propagation are reviewed. An analogy is drawn between steam explosions and chemical combustion, stressing that a continuum of steam explosion intensities can exist, ranging from very weak deflagration-like phenomena to full-scale detonation-like explosions. Evidence is presented to support several hypotheses: (1) that most, if not all, reported steam explosions were not strong steady thermal detonations; (2) that unsteady, oscillatory and partial-reaction steam explosions may exist for a wide range of fragmentation times; (3) that steam explosions may have large reaction zones (or interaction regions) of the order of several meters; (4) that fragmentation times of the order of 40--200 /mu/s may be fast enough to sustain strong thermal detonations; (5) that explosion strength can increase dramatically with trigger strength; and (6) that the product of pressure and impulse may be good measure of trigger strength. New experimental data and calculations are presented to support some of these hypotheses. 84 refs., 19 figs., 1 tab.
This report presents a evaluation of ten video compression systems currently available on the market. The products are presented in a structured format for easy comparison. The features used for comparison purposes include applications, bit rates, processing delays, resolutions, color capabilities, physical size and weight, maintainability, price, and additional features. Further, unique attractions and characteristics, as well as limitations and problems, are discussed.
We at Sandia first became involved with developing energy technology when the nation initiated its push toward energy independence in the early 1970s. That involvement continues to be strong. In shaping Sandia's energy programs for the 1990s, we will build on our track record from the 70s and 80s, a record outlined in this publication. It contains reprints of three issues of Sandia's Lab News that were devoted to our non-nuclear energy programs. Together, they summarize the history, current activities, and future of Sandia's diverse energy concerns; hence my desire to see them in one volume. Written in the fall of 1988, the articles cover Sandia's extremely broad range of energy technologies -- coal, oil and gas, geothermal, solar thermal, photovoltaics, wind, rechargeable batteries, and combustion.
Thermal energy contained in magmatic systems represents a huge potential resource. In the US, useful energy contained in molten and partially-molten magma within the upper 10 km of the crust has been estimated at 50,000 to 500,000 Quads. The objective of the Magma Energy Extraction Program is to determine engineering feasibility of locating, accessing and utilizing magma as a viable energy resource. Engineering feasibility will depend on size and depth of the resource; extraction rates; and material life times. 11 refs., 29 figs., 1 tab.
The diffusion of unreactive solutes through the Culebra Dolomite was studied experimentally and theoretically. The measured diffusive flux is less than that predicted from independent knowledge of the porosity and reasonable estimates of tortuosity. This low measured flux led to a review of the relationship between solute diffusion and pore geometry in rocks and sediments. Solute transport in hypothetical pore networks, where the effect of pore geometry on the solute flux is directly calculable, is examined. A conventional interpretation of pore tortuosity, as a normalized length of diffusion through a pore, loses meaning for cases where pores intersect in networks. Some important variables affecting the tortuosity are: (1) the distribution of pore sizes (2) the distribution of pore lengths, (3) the number of pores which intersect at a node, and (4) the pore shape between nodes. Furthermore, in porous materials with a preferential distribution of pore sizes and orientation, tortuosity is a tensor. For the Culebra Dolomite, the wide range of pore sizes causes the diffusive flux to vary considerably from that predicted from conventional theory. These results indicate that diffusive fluxes from fractures into rock pores may be smaller than previously thought. 35 refs., 10 figs., 2 tabs.
We describe the relationship between constant resistive load, constant current, and constant voltage discharges of electrochemical cells using the concept of the polarization curve. This concept is demonstrated under constraints for a prismatic Li/SOCl{sub 2} laboratory cell. We show that each of these discharges yields the same information about the electrochemical couple which drives the cell. 8 figs.
LEXER is a useful tool for lexical analysis. It is designed to give an application programmer the ability to write code that will quickly parse commands to an interactive program. It is also useful in parsing character data stored in a file. This is done by lexically analyzing the input character string and placing its components and related information into arrays stored in common blocks. The code is written in FORTRAN which conforms to the ANSI Standard FORTRAN 77 in all but a few carefully documented areas. 2 refs.
Teleoperation of land vehicles was studied to investigate the effects of both spatial and temporal video resolution on the ability of the operator to effectively control the vehicle. Teleoperation extends part of a human operator's presence into remote or hazardous areas, and the predominant form of sensory feedback is that of vision. The quality of the transmitted video information has a significant effect on the operator's confidence and ability to effectively control the vehicle. Experiments were constructed to allow subjective evaluation of the lower limits of video quality necessary for degraded, yet effective, Teleoperation. Subjects were asked to teleoperate a remote vehicle under varying conditions to degraded spatial and temporal resolution, and their comments were recorded along with the video driving scenes during teleoperation. Subjective assessments and teleoperation test data suggest the possibility of reducing the required video bandwidth for teleoperation by a factor of 28:1 over normal video standards. 9 refs., 18 figs., 9 tabs.
This document is a collection of abstracts of papers prepared as part of the Sandia programs in the GeoEnergy Technology Department and other closely related research. Areas of technology represented are resource access (drilling, blasting), resource extraction (enhanced recovery) and geodiagnostics. More basic work in the Geosciences is in a separate chapter. Industry programs and Technology Transfer constitute a final section. That section also includes our geotechnical support to DOE on the Strategic Petroleum Reserve in which we work closely with the SPR site contractor. 65 refs.
The Rankine Hugoniot equation relating the conversion of momentum across a shock front and the empirical relationship for shock velocity as a function of particle velocity are used to calculate the impact pressures for selected materials. The shock velocity and particle velocities are then calculated as a function of impact pressures. The calculated data are graphically presented sets of three figures for the selected materials as follows: Impact pressure as a function of impact velocity, impact pressure as a function of particle velocity, impact pressure as a function of shock velocity. Given the projectile impact velocity and material Hugoniot information, this graphical representation of the data allows for a fast approximation of the impact pressure particle velocity, and shock velocity in the target material. 9 refs., 1 fig., 3 tabs.
Operational procedures for the Space Systems Department and Space Sensors Department are described. Departmental policies and procedures from design of systems for space applications through qualification for spaceflight are summarized. 1 fig.
This document contains a report of the work performed in the Solar Industrial Process Heat Project during the period FY 1984 to FY 1986. The work involved seventeen experiments funded by the Department of Energy. The report contains a description of each of the active experiments and a discussion of their system performance, operation, and maintenance experience during the last three years of the project. Emphasis is placed on energy production and on economic considerations. It also contains a brief statement of the status of the solar equipment for systems no longer in operation. The project was sponsored by the Systems Test and Evaluation Branch of the Division of Solar Thermal Technology, Department of Energy. 24 refs., 35 figs., 24 tabs.
A preliminary investigation of shock compression and release properties has been performed on four ceramics: silicon carbide, titanium diboride, boron carbide and zirconium dioxide. Eight planar impact experiments using thin discs of similar ceramic as impactor and target have been completed. The particle velocity history at the interface between the back of the target ceramic and a lithium fluoride window material was acquired with a laser velocity interferometer (VISAR). These wave profiles indicate that each of these materials responds in a unique way to shock loading. Peak impact stresses in these experiments range between 20 and 50 GPa, leading to pronounced permanent deformation behavior of these materials. Dynamic compression and release stress-strain behavior of the ceramics, formulated with numerical iteration methods, is compared with compressive strength properties determined from the experimental data. The current experiments provide data for these ceramic materials which can be used to evaluate computational material models in wave propagation codes. 23 refs., 25 figs., 4 tabs.
This report describes the development, fabrication, and testing of a high-g piezoelectric accelerometer that uses PVF/sub 2/ as the piezoelectric transducer. The accelerometer is designed to continuously measure accelerations up to 1000,000 g. The device is packages in a 3/8'' hex head bolt and can include a built-in hybrid buffer to provide a low-output impedance analog signal. Included in this report are fabrication procedures, mechanical drawings, and software listings for test data analysis programs. 30 refs., 21 figs.
This paper discusses the following topics: semicustom integrated circuits; radiation effects and hardness; circuit design considerations; the design cycle; fault analysis and design for test; and circuit layout.
The Strategic Petroleum Reserve (SPR) cavern fluid velocity model for natural convection uses the Modified Local Similarity (MLS) method to analyze the boundary layer behavior. In order to use the MLS approach, boundary layer velocity and temperature profiles are calculated in terms of local similarity variables based on the natural convection equations. Modifications were made to the local similarity equations enabling consideration of turbulent flow and mixed convection conditions. The details of these changes are addressed in this report. 80 refs., 43 figs., 3 tabs.
Flame acceleration and deflagration-to-detonation transition (DDT) studies have been conducted in a 19.4-cm high, 14.5-cm wide, and 2. 242-m long channel (MINIFLAME) that is a 1:12.6 scale model of the 136-m{sup 3} FLAME facility. Tests were conducted with two levels of hydrogen concentration -- 20% and 30%, with and without obstacles in the channel, and with three levels of transverse top venting -- 0%, 13%, and 50%. The flame acceleration results in MINIFLAME are qualitatively similar to those in FLAME; however, the small-scale results are more benign quantitatively. The results show that insufficient venting, 13% venting in this case, can promote flame acceleration due to turbulence produced by the flow through the vents in smooth channels. However, with obstacle-generated turbulence in the channel, 13% top venting was found to be beneficial. Flame acceleration resulting in DDT was shown to occur in as little as 35 liters of mixture. Comparison of the DDT data with obstacles in MINIFLAME and FLAME supports d/{lambda} scaling of DDT, where {lambda} is the detonation cell width of the mixture and d is the characteristic open diameter of the channel. In the MINIFLAME and FLAME tests, DDT occurred for d/{lambda} greater than approximately three. Comparison with other experiments shows that the value of d/{lambda} for DDT is not constant but depends on the obstacle type, spacing, and channel geometry. The comparison of MINIFLAME and FLAME experiments extends the use of d/{lambda} scaling to different geometries and larger scales than previous studies. Small-scale-model testing of flame acceleration and DDT with the same combustible mixture as the full-scale prototype underpredicts flame speeds, overpressures, and the possibility of DDT. 18 refs., 16 figs.
The International Thermonuclear Experimental Reactor (ITER) is a joint design and R D project involving the USA, the Soviet Union, Japan and the European Community. These international partners are working together on the design of a fusion tokamak reactor that will operate in the D-T ignition regime. This report compiles the contributions to ITER made by Sandia National Laboratories in the area of design and R D for plasma facing components, such as the first wall and divertor. The following topics are discussed: divertor fabrication issues, divertor thermal-hydraulic analysis, separatrix sweeping effects, divertor tile 2-D stress analysis, electromechanical disruption effects, runaway electron and intense energy deposition analyses, lifetime analysis and tritium retention in plasma facing materials. Material properties for pyrolytic graphite and beryllium are presented. Use of pyrolytic graphite as the plasma facing material allows for operation with thicker graphite armor at the design heat flux level of 10 MW/m/sup 2/. The design of a divertor coated with plasma sprayed beryllium is presented as an attractive alternative to pyrolytic graphite armor tiles. Finally, the Sandia research and development plan for ITER is discussed. 82 figs.
Recent technological advances in the field of electronics have made video imaging a viable substitute for the traditional Polaroid/trademark/ picture used to create photo ID credentials. New families of hardware and software products, when integrated into a system, provide an exciting and powerful toll which can be used simply to make badges or enhance an access control system. This report is designed to make the reader aware of who is currently in this business and compare their capabilities.
This document describes twelve different kinds of charts which have been designed to help manage the performance of the Engineering Information Management (EIM) computer systems at Sandia National Laboratories Albuquerque. Operational data generated by the two major software systems, Multiple Virtual Storage (MVS) and Integrated Database Management System (IDMS), are summarized to visually portray actual service levels and meaningful system performance characteristics. To demonstrate the potential utility of the resulting performance reports, summarized data in illustrative charts are evaluated from a managerial point of view. The resulting graphs can stimulate relevant analyses for modeling the impact of forecasted workloads on system service level objectives and identifying problems or trends that need the attention of system tuners. 15 figs.
An overview of the DOE nuclear weapons research, development, and testing program is given along with a description of the program objectives and the roles and responsibilities of the various involved organizations. The relationship between the DoD and DOE is described and the division of responsibilities for weapon development as well as the coordinated planning and acquisition activities are reviewed. Execution of the RD T program at the nuclear weapons laboratories is outlined. 24 refs., 3 figs.
This report describes an integrated network management tool designed to minimize the time and effort required to diagnose and resolve data communications problems at Sandia National Laboratories, Albuquerque. A workstation is utilized to consolidate several functions necessary for diagnosing these problems, thus reducing the amount of hardware required for troubleshooting. Functions include managing data PBX and PACX switches, accessing circuit database information on a VAX, and monitoring alarms. In addition to consolidating functions, enhanced capability is provided for simplifying the complex procedure of troubleshooting data PBX problems. The first two sections of this report give an introduction and overview of the network management applications and the last section provides details of operation. 17 figs.
This report covers the initial characterization of two new dc magnetron sputtering systems which were acquired for the purpose of modernizing our capability for the deposition of tantalum nitride, titanium, and palladium thin films for HMC applications. These systems were purchased to replace two old metallization systems which had been used in this application for more than a decade. Parametric studies were carried out to characterize the systems. Operating conditions were established for the deposition of tantalum nitride films in one system and for the deposition of Ti/Pd films in the other system. These conditions were shown to produce films with properties equal to or better than were being achieved with the equipment being replaced. In addition, the new equipment was found to be simpler and easier to operate than the old systems. The data obtained during the course of this characterization study are presented. 15 refs., 44 figs., 8 tabs.
Preliminary atomic Xe laser results are presented for e-beam excitation at pump rates between 40 W/cm/sup 3/ and 1 kW/cm/sup 3/ and for pump times between 50 /mu/s and 1 ms. 44 refs., 15 figs., 2 tabs.
A computer code for calculating hydraulic fracture height and width in a stressed-layer medium has been modified for easy use on a personal computer. HSTRESS allows for up to 51 layers having different thicknesses, stresses and fracture toughnesses. The code can calculate fracture height versus pressure or pressure versus fracture height, depending on the design model in which the data will be used. At any pressure/height, a width profile is calculated and an equivalent width factor and flow resistance factor are determined. This program is written in FORTRAN. Graphics use PLOT88 software by Plotworks, Inc., but the graphics software must be obtained by the user because of licensing restrictions. A version without graphics can also be run. This code is available through the National Energy Software Center (NESC), operated by Argonne National Laboratory. 14 refs., 21 figs.
With the advent of automated photographic badge making systems and automated access control systems, the need for new badge making strategies has become evident. In order to determine the suitability of the polyester/polyethylene badge packet for application to both the currently widely used Polaroid (TM) photographic process and the emerging automated photographic badge making process, Sandia National Laboratories procured samples of this type of badge packet from four different suppliers and evaluated them. The evaluation packet was designed to accommodate either process as well as an automated access control system (in this case, a system based on magnetic stripe technology). The evaluation consisted of environmental, mechanical, chemical and magnetic tests to determine reliability and durability. These tests included a flex test at /minus/20/degree/F, 76/degree/F and 125/degree/F; a washing machine test; a magnetic stripe wear test; an outdoor test; and a high magnetic field exposure test. These tests were designed to simulate conditions the badge might encounter during normal use. 5 tabs.
Prototype systems have been established which prove the concept and utility of supporting distributed access to shared Product Test Data from Sandia National Laboratories (SNL) and General Electric Neutron Devices (GEND) using existing network communications facilities. It is essential, however, that adequate control (audit and isolation) be present as intrinsic characteristics of this connectivity in the production environment. A plan has emerged to put into place a configuration which provides required network functionality, yet preserves the necessary control. This configuration supports further development of a Product Data Network containing a Distributed Data System. We anticipate a complete ''black hat'' assessment of the final plan and configuration which results from these efforts. 3 figs.
Sandia conducts impact testing for a variety of structures. In this slapdown test, one end of the cask impacts the hard concrete target, then the structure rotates so that the other end of the cask impacts the target. During an impact test, metal to metal contact may occur within the structure and produce high frequency, high amplitude shock inputs. The high frequency portion of this transient vibration has been observed to excite the accelerometer resonance even though this resonance exceeds 350 kHz. The amplitude of the resonating accelerometer response can be so large that the data are clipped and are rendered useless. If the data are not clipped, a digital filter must be applied to eliminate the undesired accelerometer resonant response. If possible, it is more desirable to prevent excitation of the accelerometer resonance, This may be accomplished by mechanically isolating the accelerometer from the high frequency excitation without degrading the transducer response in the bandwidth of interest which is usually 10 kHz or less. To achieve this desirable isolation, two mounting configurations were designed and characterized. The objective of this paper is to describe the evaluation technique and to discuss the shock isolation properties of each mounting configuration. One configuration was actually used in a field test of bomb impacting a target. 4 figs.
A number of problems have been experienced by Sandia secretaries and others in the preparation of equations. This report is a self- paced/''how-to'' manual designed to provide detailed explanations on the preparation of equations using Mass-11 and the typewriter and is suitable for either classroom training or on-the-job use.
A computer controlled servo-hydraulic mechanical test system has been configured to conduct automated fatigue crack growth testing. This provides two major benefits: it allows continuous cycling of specimens without operator attention over evenings and weekends; and complex load histories, including random loading and spectrum loading, can be applied to the specimens to simulate cyclic loading of engineering structures. The software is written in MTS Multi-User Basic to control test machine output and acquire data at predetermined intervals. Compact tension specimens are cycled according to ASTM specification E647-86. Fatigue crack growth is measured via specimen compliance during the test using a compliance/crack length calibration determined earlier by visual crack length measurements. This setup was used to measure crack growth rates in 6063 aluminum alloy for a variety of cyclic loadings, including spectrum loads. Data collected compared well with tests run manually. 13 figs.
A liquid-metal pool-boiler solar receiver has been proposed to link a paraboloidal-dish concentrator to a Stirling heat engine operating in the temperature range 700--800/degree/C. Preliminary to the construction of a full-scale receiver of this type, a bench-scale version using liquid sodium was designed, built and tested. Conclusions drawn from the test included: (1) boiling instability will occur in the full-scale receiver unless special measures are taken, (2) boiling was stabilized in the bench-scale receiver after the addition of ''artificial cavities'', but other stabilizing influences may also have been present, (3) ''hot restarts'' can under some circumstances lead to unacceptably-high incipient-boiling superheats, (4) no thermal-fatigue damage was evident after 100 hours of boiling interspersed with 24 cooldown periods, (5) 0.01-inch-diameter sheathed thermocouples used to provide an estimate of heated-wall temperature survived over 100 hours at 830/degree/C, and (6) other instrumentation and control techniques that were tested were shown to be appropriate for future full-scale receiver tests. 27 refs., 24 figs., 4 tabs.
A program has been written that allows us to predict the trace-to- trace cross-coupling on printed circuit boards for many geometries of practical interest. It combines multiconductor transmission line analysis with circuit analysis in the time domain. Multiple sections of uniform lines, of varying number and characteristics, can be interconnected by passive circuit elements. These circuit elements may represent physical components or the effects of discontinuities in the lines. These predictions were compared with measurements for simple geometries, with good agreement in both waveshape and amplitude. The major discrepancies were in the amplitudes of fast rising spikes and are probably due to the fact that the predictions did not account for the increasing attenuation at high frequencies. 10 refs., 12 figs.
This report presents preliminary analyses of the Nunnally mass launcher. The Nunnally launcher is much like ones described in US Patents 1,370,200; 1,421,435; and 1,422,427 which were issued to A.L.O. Fauchon-Villeplee in the period 1917--1922. A discussion of why a high conductivity projectile impulsively accelerated in a uniform transverse B-field does not experience a drag force, even for very large magnetic Reynolds numbers (R/sub m/ = 10/sup 2/ /minus/ 10/sup 4/) is also presented. 1 ref., 7 figs.
The thermomechanical fatigue behavior of solder joints is a critical reliability issue in electronic packaging. A need exists for a thorough metallurgical understanding of solder joints in conditions of thermal fatigue. This paper presents a method to test solder joints under conditions of thermomechanical fatigue. This method involves simultaneous imposition of temperature and strain cycles on discrete solder joints in a shear orientation. The stress, microstructure, and number of cycles to failure are monitored. Cycles to failure are determined by a continuous electrical resistance detection method. 60Sn-40Pb and 40Sn-40In-20Pb solder joints were tested using this new method at 20% shear strain. 4 refs., 7 figs.
This report provides an introduction to the capabilities of a new experimental test system recently acquired by Department 1830 and installed into the Organization 1000 bay of the microelectronics Development Laboratory, Building 858. This device - the Nano..delta..Indenter/Trademark/ - is a state of the art ultra-low load indentation hardness tester. It is a computer-controlled load and depth sensing instrument with depth resolution of 0.2 nm and load resolution of 0.3 ..mu..N. Initial testing has now been performed using this machine, verifying that it will be a unique addition to our existing mechanical test capabilities. 3 refs., 8 figs.
From the beginning of the geothermal development program, Sandia has performed and supported research into polycrystalline diamond compact (PDC) bits. These bits are attractive because they are intrinsically efficient in their cutting action (shearing, rather than crushing) and they have no moving parts (eliminating the problems of high-temperature lubricants, bearings, and seals.) This report is a summary description of the analytical and experimental work done by Sandia and our contractors. It describes analysis and laboratory tests of individual cutters and complete bits, as well as full-scale field tests of prototype and commercial bits. The report includes a bibliography of documents giving more detailed information on these topics. 26 refs.
Analyses of the final state of collapse of various types of contact-handled waste drums are required to assess of the performance of the waste storage areas in the Waste Isolation Pilot Plant. To provide data for calculations, tests must use simulated, instead of actual waste. Data on the contents of the principal categories of contact-handled transuranic waste from the Idaho National Engineering Laboratory were used to define standard compositions of simulated waste. Categories of baseline waste will be created by mixing appropriate amounts of the simulants together. Selection of materials is discussed. Methods for estimating the consolidation characteristics of simulated waste are also described. Theoretical solid densities, theoretical solid compressibilities, and initial void volumes of various waste components are estimated, and a method for estimating consolidation curves in the absence of experimental data is described. 9 refs., 14 figs., 11 tabs.
The research and development described in this document were conducted within the US Department of Energy's Solar Thermal Technology Program. The goal of the Solar Thermal Technology Program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. This bibliography cites, with a few additions, all the documents that were published by, or sponsored by, Sandia National Laboratories in support of the Department of Energy's Solar Thermal Technology Program and its Distributed Receiver Project. The timing of this updated bibliography is important because it marks the end of an era in which distributed receiver and central receiver research and development were pursued separately. At the beginning of fiscal year 1989, the Department of Energy initiated a restructured solar thermal research and development strategy. The new program is mission oriented, with core technology development activities supporting the missions. For instance, the advanced electric technology mission has an objective to organize industry, user, and government consortia that will field competitive next-generation solar thermal electric system experiments within five years--regardless of whether the systems are distributed or central receivers; and the concentrator development core activity will develop optical materials and concentrators regardless of application.
This document serves as the proceedings for the annual project review meeting held by Sandia's Photovoltaic Cell Research Division and Photovoltaic Technology Division. It contains information supplied by each organization making a presentation at the meeting, which was held 11-13 July 1989 at the Marriott Hotel in Albuquerque, NM. Information supplied by other Sandia contractor and single-page data sheets generated by the cognizant Sandia Technical Liasion for each contract are also included. Sessions were held to discuss national and international photovoltaic programs, one-sun crystalline silicon cell research, concentrator silicon cell research, concentrator III-V cell research, and concentrating collector development.
The Center for Compound Semiconductor Technology (CCST) was formed within the Solid-State Sciences Directorate at Sandia National Laboratories in 1988, as the culmination of a long-term thrust into compound semiconductor research and technology that began about ten years ago. At that time, it was realized that electronic and optoelectronic devices based on compound semiconductors would be necessary for photonic applications, and that they could provide greater radiation hardness, higher speed, and higher operating temperatures than comparable silicon devices and circuits. It was also realized that a successful program would require the development and integration of materials growth and processing capability, solid-state physics research, and device engineering. The program at Sandia grew steadily from the purchase of the first Molecular beam Epitaxy (MBE) system in 1981, and the discovery of strained-layer superlattices in 1982, to the completion of the Compound Semiconductor Research Laboratory in 1989. To more formally organize this effort, Sandia established the CCST in 1988, aided by $10M of funding from DARPA. The CCST comprises most of the compound semiconductor research and development activities in the Solid-State Sciences Directorate. Ongoing programs are funded by the DOE Office of Military Applications, DOE Basic Energy Sciences, DOE Conservation and Renewable Energy, and the Department of Defense. 15 figs.
Sealing a nuclear waste repository in partially saturated tuff presents unique challenges to assuring performance of sealing components. Design and performance of components for sealing shafts, ramps, drifts, and exploratory boreholes depend on specific features of both the repository design and the site; of particular importance is the hydrologic environment in the unsaturated zone, including the role of fracture flow. Repository design features important to sealing of a repository include the size and location of shaft and ramp accesses, excavation methods, and the underground layout features such as grade (drainage direction) and location relative to geologic structure. Uncertainties about seal components relate to the postclosure environment for the seals, the emplacement methods, the material properties, and the potential performance of the components. An approach has been developed to reduce uncertainties and to increase confidence in seal performance; it includes gathering extensive site characterization data, establishing conservative design requirements, testing seal components in laboratory and field environments, and refining designs of both the seals and the repository before seals are installed. 9 refs., 5 figs., 2 tabs.
Sandia National Laboratories: The Postwar Decade is organized into two major sections: Part 1: Heritage'' and Part 2: Nuclear Ordnance Engineer for the Nation.'' Within this general structure, the narrative connects a series of subjects, beginning with a Prologue that surveys the national and international events leading to development of the atomic bomb and establishment of the national laboratory complex under the Manhattan Engineer District.
Recent experiments on Lawrence Livermore's ATA indicate that there may be problems with the IFR (Ion Focused Regime) transport of the relativistic electron beam (REB) through the ATA accelerator. For beam currents greater than about 7-kA, the beam is observed to be inverse-tailored with the beam radius increasing from beam head to tail. This inverse-tailoring is considered unfavorable for endo- atmospheric beam propagation. An unusual feature of ATA's laser- produced IFR channel is that it has a rectangular cross-section. One possible explanation for the lack of good beam transport may be ion motion in the IFR channel which disrupts the tail of the beam. In this report an ATA-like electron beam, propagating on a laser-ionized rectangular IFR channel is simulated using the 3-D magnetostatic code BUCKSHOT. The simulations demonstrate that non-axisymmetric ion motion, similar to the ion hose instability, can produce an inverse- tailored electron beam similar to those found in the experiment. The simulation results should be relevant to upcoming TROLL experiments with a laser-ionized IFR channel, with several beam parameters similar to ATA's. 1 ref., 22 figs.
In late 1985, the International Atomic Energy Agency (IAEA) requested the US Program for Technical Assistance to IAEA Safeguards (POTAS) to provide a study which examined sealing concepts for application to spent fuel shipping casks. This request was approved, and assigned to Sandia National Laboratories (Sandia). In the course of this study, discussions were held with personnel in the International Safeguards Community who were familiar with the shipping casks used in their States. A number of shipping casks were examined, and discussions were held with two shipping cask manufacturers in the US. As a result of these efforts, it was concluded that the shipping casks provided an extremely good containment, and that many of the existing casks can be effectively sealed by applying the seal to the cask closure bolts/nuts.
A design for a photodetector quantum efficiency measurement test system is presented. The system hardware and control software are explained and the measurement theory is given. A brief discussion of the operation of the prototype is given. Finally, the article concludes with an example of a quantum efficiency measurement of a sample and a discussion of the errors involved in the measurement. 9 refs., 7 figs.
The Magma Energy Program of the US Department of Energy, Geothermal Technology Division, is planning to begin drilling a deep (6 km) exploration well in Long Valley Caldera, California, in September 1988. The location of the well is in the central part of the caldera, coincident with a large number of shallow (5-7 km) geophysical anomalies identified through many independent investigations. Results from the hole will permit the following: direct investigation of the geophysical anomalies interpreted to be magma; investigation of the patterns and conditions of deep fluid circulation and heat transport below the caldera floor; determination of the amount of collapse and subsequent resurgence of the central portion of Long Valley caldera; and determination of the intrusion history of the central plutonic complex beneath the caldera, and establishment of the relationship of intrusive to eruptive events. The hole will thus provide a stringent test of the hypothesis that magma is still present within the central plutonic complex. If the interpretation of geophysical anomalies is confirmed, the hole will provide the first observations of the environment near a large silicic magma chamber. 80 refs., 7 figs., 2 tabs.
A computer code for analyzing four-gage Anelastic Strain Recovery (ASR) data has been modified for use on a personal computer. This code fits the viscoelastic model of Warpinski and Teufel to measured ASR data, calculates the stress orientation directly, and computes stress magnitudes if sufficient input data are available. The code also calculates the stress orientation using strain-rosette equations, and its calculates stress magnitudes using Blanton's approach, assuming sufficient input data are available. The program is written in FORTRAN, compiled with Ryan-McFarland Version 2.4. Graphics use PLOT88 software by Plotworks, Inc., but the graphics software must be obtained by the user because of licensing restrictions. A version without graphics can also be run. This code is available through the National Energy Software Center (NESC), operated by Argonne National Laboratory. 5 refs., 3 figs.
The Sandia downhole seismic source produces vertically polarized shear waves of variable frequency. While the source has been successfully tested in the field, the practicality of the source for reservoir characterization has not been established. The principal question is whether sufficient power can be supplied to the source through practical means so that sufficient energy output can be maintained. Here we investigate the feasibility of several schemes to provide power to the Sandia downhole seismic source. 4 refs., 5 figs., 5 tabs.
Traditionally, pyrolysis combined with infrared, IR, detection of the decomposition products for the analysis of small (<1 mg) samples has been limited due to the size and geometry of commercially available pyrolysis chambers. To reduce the sample size requirements for pyrolysis-IR a system has been designed and built that allows various microgram sized polymer samples to be examined. The design incorporates a commercial pyrolysis system with a small chamber built from readily available parts. Minimal modifications of these components are required to build the system. The micropyrolyzer has been used to successfully identify various filled epoxy samples, such as three Epon 828 samples: 0.46 mg of alumina filled; 0.15 mg of mica filled; and 0.28 mg of glass microballoon, GMB, filled. 7 refs., 6 figs.
The fracture toughness of several ductile cast iron (DCI) alloys has been calculated according to two versions of the ASTM Standard covering the determination of J/sub Ic/. The original version (ASTM E 813-81) had previously been used to establish the relationship between ferritic DCI alloys and the graphite nodule spacing. The J/sub Ic/ values were recalculated by the methods of the revised version of the ASTM Standard (ASME 813-87), and were found to be 5 to 8% higher than those determined by the original standard. A linear regression analysis was used to reaffirm that the fracture toughness is directly related to the graphite nodule size or spacing. 6 refs., 8 figs., 3 tabs.
The lightning literature extant through the end of 1988 has been reviewed and used to develop an updated generic, or baseline, direct-strike lightning environment for nuclear weapon Stockpile-to-Target Sequence documents. The supporting rationale for recommended changes is given, along with a discussion of the interpretation of the environment for weapon nuclear safety assessment. 13 refs., 2 tabs.
An initial feasibility study has been completed on the ultrasonic welding of Tophet C (Ni-24 Fe-16 Cr) bridgewire to Hastelloy C-276 (Ni-16 Cr-15 Mo-4 W) pin material. A key feature of this work is that it employed a hybrid microcircuitry ultrasonic wire bonder. Much greater productivity can be expected from this process compared with traditional bridgewire welding methods. Three different ultrasonic tool designs were investigated. After selection of the best design, pull test data were acquired for both the 1st and 2nd weld locations in both heel and toe directions. Values up to 94% of the bridgewire tensile strength were obtained. With the equipment used both raised and flat bridgewire configurations are possible. While much work is still necessary to prove in the process for production applications, the work completed to date indicates the ultrasonic welding process merits further investigation. 6 figs.
Sandia National Laboratories (SNL), Albuquerque is located south of Albuquerque on Kirtland Air Force Base. Because radionuclides are potentially released in small quantities from its research activities, SNL, Albuquerque has a continuing environmental monitoring program which analyzes for cesium-137, tritium, uranium, alpha emitters, and beta emitters in water, soil, air, and vegetation. A total of 5.23 curies of argon-41 were released as a result of SNL, Albuquerque operations in 1988. The albuquerque population received an estimated 0.04 person-rem from airborne radioactive releases, whereas it received greater than 44,500 person-rem from naturally occurring radionuclides. A nonradioactive effluent monitoring program at SNL, Albuquerque includes groundwater, stormwater and sewage monitoring. Results indicate that the groundwater has not been impacted by the chemical waste landfill. Preliminary testing of stormwater showed that no pollutants were above minimum detectable levels. A program to investigate potential remedial action sites has been started. 47 refs., 12 figs., 19 tabs.
The Tonopah Test Range is located about 140 air miles north of Las Vegas, Nevada, and covers 624 square miles within the Nellis Air Force base Bombing and Gunnery Range. The range is used for various USDOE and USDOD program tests that are critical to national defense. Activities that affect the environment are mainly road construction, preparation of instrumentation sites, and disturbance of the terrain from weapons testing. Monitoring of the test range is done routinely by the US Environmental Protection Agency (EPA) to supplement Sandia's monitoring effort associated with Sandia test activities. EPA monitoring results for 1988 indicate that test range operations do not adversely affect the off-site environment or the public. 14 refs., 2 figs., 11 tabs.
During the period October 1988 through December 1988, a search was made for very high energy gamma rays from the direction of the Crab nebula using the atmospheric Cerenkov technique. The detector consisted of seven-fold arrays of photomultiplier tubes at the focii of two 11-meter diameter solar concentrators situated in Albuquerque, New Mexico. A DC signal was detected from the Crab nebula with a statistical significance of 5.8 sigma after the application of various cuts designed to suppress the background of hadronic showers. A search for a pulsed component failed to identify a significant signal in phase with the radio pulse from the Crab pulsar. These results with a threshold energy of 200 GeV are in substantial agreement with high energy results recently reported by the Mt. Hopkins group. 16 refs., 3 figs., 3 tabs.
A two-dimensional model of melt progression, oxidation and natural convection in reactor core debris beds has been developed. Three fields are considered in the model: vapor, melt and solid. Conservation equations are solved for the species of interest in each field. Momentum equations that are based on Darcy's law are solved for the vapor and the melt and a simplified model is used to calculate the motion of the solid as it settles downward. An energy equation is included that accounts for melting/freezing, convection, conduction, oxidation and decay heating. Key results from a sensitivity study include: (1) gas velocities increase rapidly at the onset of oxidation and subsequently decrease when the bed becomes steam-starved; (2) natural convection flows are sensitive to radial variations in the decay heat; (3) raising the pressure in the bed and the upper plenum increases the amount of steam that is available for oxidation and leads to much higher temperatures and gas velocities; (4) reducing the average particle diameter decreases the permeability and significantly lowers gas velocities; and (5) solutions are sensitive to conditions in the upper plenum and consequently, melt progression models discussed here must be coupled to a mechanistic code, such as MELPROG or SCDAP, in order to analyze specific accident sequences. 33 refs., 20 figs.
One critical issue to be addressed in the compact recirculating linac program concerns optimal beam injection into a racetrack-shaped accelerator. There are at least three candidates, axial beam injection, tangential beam injection, and laser-channel-assisted beam injection. In this report these three approaches are examined using computer simulation techniques. 3 refs., 27 figs., 2 tabs.
This report summarizes the current understanding of the expected long-term behavior of the Waste Isolation Pilot Plant (WIPP) repository and estimates long-term radionuclide doses in a series of six analyses investigating both undisturbed repository (Case I) and performance in response to a relatively high-consequence human intrusion (Case II). It is the result of an intensive effort over a short time. The US Department of Energy (DOE) decided to have Sandia National Laboratories prepare this report as a result of a meeting held January 5, 1989. The conceptual model of the expected long-term behavior of the WIPP repository used in this report was formulated in early to mid January 1989, drawing and understanding developed over the past decade. Numerical modeling of ground-water flow, radionuclide transport, and doses to humans began January 20, 1989 and was completed March 20, 1989. 332 refs., 98 figs., 69 tabs.
The particle code MAGIC and the trajectory code TRAJ were used to model diodes, gaps, and conditioning cells for several of Sandia's linear electron accelerators. In this report we summarize the main results obtained and discuss their significance. 29 refs., 50 figs., 10 tabs.
The US Department of Energy is planning to dispose of transuranic wastes at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. Sandia National Laboratories is responsible for evaluating the compliance of the WIPP with the Environmental Protection Agency's Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). This plan has been developed to present the issues that will be addressed before compliance can be evaluated. These issues examine the procedural nature of the Standard, and the technical requirements for further characterizing the behavior of the disposal system, including uncertainties, to support the compliance assessment. The plan briefly describes the activities that will be conducted prior to 1993 by Sandia to characterize the WIPP disposal system's behavior and predict its performance. 41 refs., 35 figs., 21 tabs.
Computer simulations, using the hydrocode HULL, were performed to analyze a method to discard the sabot and the effectiveness of several designs in reducing the kinetic energy of pusher plates for Davis Gun systems. This study assumed an axisymmetric impact of the pusher plate on one metal and multi-metal annual plates. Based on these simulations, a four petal sabot that is mechanically attached to the penetrator and an aluminum-steel composite target plate are recommended. 12 refs., 27 figs.
The IAEA is increasingly confronted with decisions on how to use operator designed monitoring systems. A major question in the use of such systems focuses on how they may be authenticated. This report identifies four major areas of concern for authentication of an operator designed system. Generic methods to address these areas of concern are presented. Suggestions are also given on design features an operator can incorporate when designing a system which will aid in the application of authentication techniques.
Over 4100 ft (1100 ft oriented) of Mesaverde core was taken during the drilling of the three Multiwell Experiment (MWX) wells, for study in a comprehensive core analysis program. This core traversed five separate depositional environments (shoreline/marine, coastal, paludal, fluvial, and paralic), and almost every major sand in the Mesaverde at the site was sampled. This paper summarizes MWX core analysis and describes the petrophysical properties at the MWX site; reservoir parameters, including permeabilities of naturally fractured core; and mechanical rock properties including stress-related measurements. Some correlations are made between reservoir properties and mineralogy/petrology data. Comparisons are made between the properties of lenticular and blanket sandstone morphologies existing at the site. This paper provides an overview of a complete core analysis in a low-permeability sandstone reservoir. 66 refs., 17 figs. , 9 tabs.
A very simple algorithm is presented that allows particles to be loaded or initialized in a particle simulation code. The algorithm can load particle positions or velocities according to any well- behaved density or distribution function. Sample codes are given in 1, 2, and 3 dimensions. The technique is highly efficient. 2 refs., 9 figs., 3 tabs.
Experiments were run using a PC-100 ion mobility spectrometer and TNT explosive vapor source to evaluate the adsorb-desorb characteristics of select 6.2 mm O.D. by 4.0 mm I.D. by 76.2 mm long glass preconcentrator tubes. This study was done to aid in the continuing search for an efficient preconcentrating device to be used with explosive vapor detecting instruments. These tubes were tested at various sampling rates ranging from 60 to 510 ml/min and the samples were thermally desorbed to provide the maximum output signal. Data showed the tubes with the greatest internal surface area for the explosive molecules to stick to produced the best desorption results, namely the glass wool packed tubes. Correlation between tube type and sampling flows with respect to maximum output signal proved to be significant, along with the individual tube desorption profiles. 23 figs.
Hermes III is a 20-megavolt, 15-terawatt, pulsed accelerator which is available for gamma-ray testing. The purpose of this guide is to serve as a basic source of information for prospective users of Hermes III. Included is a brief discussion of the design and operation of the accelerator and a summary of gamma-ray environmental data. The guide also contains a description of experimental support facilities, data acquisition and analysis systems and general information for users. 6 refs., 16 figs.
Characterizing the explosive dispersal of inert solid particles is of interest in a number of applications. A mixture theory approach is used to calculate the radial motion of the gas-solid mixture as it expands into an infinite atmosphere. Two initial gas-solid configurations are considered. In the first, a core of high pressure gas initially at rest is surrounded by a porous shell of the solid. The other configuration considered is a uniform mixture of solid and gas throughout the sphere. An adaptive finite element method is used to solve the set of partial differential equations for mass, momentum and energy conservation in each phase as well as the compaction equation for the time evolution of solid volume fraction. An adaptive grid scheme is used to refine the mesh to limit discretization errors. This places a fine mesh near the porosity and pressure fronts and greatly reduces the spatial resolution in areas of relatively constant pressure and volume fraction. The dispersal of the solid for the two initial configurations shows quite different behavior. For the gas core and porous shell, the solids are initially compacted to a maximum density of /approximately/80--90% in a very thin region before rapidly dispersing to a broad concentration distribution. For the homogeneous gas-solid sphere, however, there is only a slight compaction region at the leading edge of the expanding gas, and the concentration of solid decays rapidly. 25 refs., 32 figs., 5 tabs.
The purpose of this report is to provide some basic information to beginning users of Department 9140's Computer-Aided Engineering (CAE) workstations. These workstations are all Digital Equipment Corporation (DEC) color VAXstations, and they use the VAX/VMS operating system. This manual shows users how to boot the workstations, login, use the window interface, and use some basic VMS commands. It also discusses some of the CAE software available on the workstations, such as ANVIL-5000. References are given so users can get additional information. 25 refs., 27 figs.
The difficulty of detecting, locating and identifying low-magnitude seismic events has been an ongoing problem. In this note, we describe processing methods that help us to find low-magnitude seismic events. A series of algorithms with beamforming has been developed and has proven effective in helping to discover very low yield events. The beamforming technique consists of determining the array element time delays for the specific source region using previously established events. This allows us to concentrate the array to look at the specified source location. Examples of this type of analysis are provided. In the analysis of seismic data one may be in possession of other information, e.g., newspaper reports of an earthquake. Using this information to concentrate the search for an event will often identify an otherwise overlooked signal. The algorithms for this type of search are incorporated into computer software that includes capabilities for plotting, spectral and signal-to-noise estimation, direction finding, and other functions. 2 refs., 25 figs.
A new program, ELLIPSE, for the analysis of ellipsometric data is described. The program is interactive and includes on-line help, performs explicit error analysis for single-angle-of-incidence measurements, allows the input of four-zone null data, and performs least-squares analysis of multiple-angle-of-incidence data. Solutions for the transparent-film-on-substrate model are obtained using decoupled equations for film thickness and index. No initial guess is required for thickness, and the algorithm is insensitive to the initial guess for film index. This document combines the user's manual and program description for ELLIPSE, and includes several examples of its use. 11 refs.
One of the factors considered in the design of critical concrete structures is the estimation of the global elasto-plastic structural response caused by the accidental impact of an aircraft. To estimate the response of the structure, the impact force (the force versus time relationship) must be known. Previous analytical studies have derived the forcing function using the impact velocity of the aircraft and the calculated mass and strength distribution of the aircraft. This paper describes a test conducted on April 19, 1988, at an existing rocket sled facility at Sandia National Laboratories in Albuquerque, New Mexico, USA, in which an actual F-4 Phantom aircraft was impacted at a nominal velocity of 215 m/s into an essentially rigid block of concrete. This was accomplished by supporting the F-4 on four struts that were attached to the sled track by carriage shoes to direct the path of the aircraft. Propulsion was accomplished by two stages of rockets. The concrete target was 'floated' on a set of air bearings. Data acquisition consisted of measurements of the acceleration of the fuselage and engines of the F-4, and measurements of the displacement, velocity and acceleration of the concrete target. High-speed photography recorded the impact process and also permitted the determination of the impact velocity. This paper describes the test plan, method and results, while a companion paper discusses the analyses of the results. 6 refs., 11 figs.
A related function takes place in situations where an intermediate memory device may be used to store the unique signal information. In this case, ''verification patterns'' are communicated back to the source as status of the memory in which the unique signal is stored. If properly used, unique signals and verification patterns can support acceptable abnormal-environment nuclear detonation safety. If improperly used, there is danger of a false sense of complacency. In this report, the potential danger of misunderstanding the implications of abnormal environments is described. Unfortunately, a number of common normal-environment assumptions and analytical techniques are sometimes applied to abnormal environment situations. Several of these are shown to be misleading for assessing unique signal performance in abnormal environments. Misapplied approaches can encourage communication system design features that may seriously degrade nuclear detonation safety. 8 refs., 10 figs.
To analytically model soldering and welding processes it is necessary to track the deformation of a material as it changes from a solid to a liquid and then back again to a solid. Because it is the residual stress state in the solid that is of primary interest, the most suitable tools for studying this class of problems appear to be Lagrangian finite element codes that are typically used in the analysis of solids. It is possible to obtain solutions to hydrostatic fluids problems using a Lagrangian finite element code by allowing the ''fluid'' phase of the material to sustain a deviatoric stress component that is very small in magnitude relative to the hydrostatic pressure that exists in the material. The capability to model surface tension phenomena was added to the finite element code SANCHO. SANCHO is a Lagrangian finite element code that uses a dynamic relaxation scheme to solve nonlinear problems involving quasistatic loading of two-dimensional solids. SANCHO is formulated so that it properly accounts for large deformations. This report details the theory and implementation of the method used to model surface tension. With this new capability, SANCHO can be used to solve surface tension problems that are more complex than the problems that can be treated with other more tradition methods of surface tension analysis. 3 refs., 10 figs.
GEN3D is a three-dimensional mesh generation program. The three- dimensional mesh is generated by mapping a two-dimensional mesh into three dimensions according to one of four types of transformations: translating, rotating, mapping onto a spherical surface, and mapping onto a cylindrical surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, and revolving about an axis. GEN3D can be used to mesh geometries that are axisymmetric or planar, but, due to three-dimensional loading or boundary conditions, require a three-dimensional finite element mesh and analysis. More importantly, it can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two-dimensional geometries. The code GJOIN is then used to join the separate sections into a single body. GEN3D reads and writes two-dimensional and three- dimensional mesh databases in the GENESIS database format; therefore, it is compatible with the preprocessing, postprocessing,and analysis codes used by the Engineering Analysis Department at Sandia National Laboratories, Albuquerque, NM. 19 refs., 7 figs.
The LeCroy 6880 uses 32 interleaved linear CCD arrays to digitize data up to 250 MHz. Each CCD array has different offset, droop, and gain characteristics. To obtain usable data once the outputs from the CCDs are interleaved, the raw data must be ''corrected'' to account for these different characteristics. This report describes the DC corrections used on raw data to compensate for the differences in CCD characteristics. 5 refs., 12 figs.
An electron moving in the magnetic field generated by a current-carrying rod will drift in the direction defined by the rod. The motion can be characterized by two dimensionless parameters,/var epsilon/ = 2eI/mc/sup 3/..gamma beta.. and xi = (v/sub /phi///v)exp(v/sub z///var epsilon/v). The drift velocity can be computed by numerical integration for arbitrary values of /var epsilon/ and xi. Analytic solutions are derived for the limiting cases xi = 0 and /vert bar/xi/vert bar/ = xi/sub MAX/. Series solutions are derived that are accurate in the limit /vert bar/xi//var epsilon//vert bar/ << 1. A simple algorithm is developed that has an error of less than +- 0.08% for /var epsilon/ greater than or equal to 2. 14 refs., 18 figs.
This report discusses the application of finite-element methods to the solution of magnetostatic field problems. A brief description is given of the finite-element representation of the magnetostatic field. Two computer codes which solve this problem are described. The code MAGNUM is commercially available and the code ISO is a Sandia in-house product. Both codes are currently available on the Sandia CRAY. Some general remarks are presented on modeling techniques and boundary conditions. A new method for estimating solenoid magnetic forces and dynamic response is described. A suite of codes for generating various electromagnetic devices is briefly discussed. Finally, some numerical results are presented. 6 refs., 10 figs.
Sandia National Laboratories operates the Primary Standards Laboratory (PSL) for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the second half of 1988 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program. 8 refs.
The FAC-SIM factory simulation environment provides systems analysis capabilities during the natural top-down design process for industrial facilities. Models can be constructed and simulations run for coarse descriptions of facility systems and process operations. Detail can be added incrementally to the models as the design progresses. Simulations run with FAC-SIM can identify critical subsystems and determine the impacts of variations in system design and operations. The graphical and hierarchical representations of both physical objects and operations are the unique features of FAC-SIM that permit ease of top-down simulations. This paper describes the FAC-SIM environment and its use in the ongoing development of the Repository Simulation System, REPSIMS, for the analysis of surface facilities at geological repositories for radioactive waste. 13 refs., 5 figs., 5 tabs.
Nuclear deterrence, a cornerstone of US national security policy, has helped prevent global conflict for over 40 years. The DOE and DoD share responsibility for this vital part of national security. The US will continue to rely on nuclear deterrence for the foreseeable future. In the late 1950s, Sandia developed satellite-borne nuclear burst detection systems to support the treaty banning atmospheric nuclear tests. This activity has continued to expand and diversify. When the Non-Proliferation Treaty was ratified in 1970, we began to develop technologies to protect nuclear materials from falling into unauthorized hands. This program grew and now includes systems for monitoring the movement and storage of nuclear materials, detecting tampering, and transmiting sensitive data securely. In the late 1970s, negotiations to further limit underground nuclear testing were being actively pursued. In less than 18 months, we fielded the National Seismic Station, an unattended observatory for in-country monitoring of nuclear tests. In the mid-l980s, arms-control interest shifted to facility monitoring and on-site inspection. Our Technical On-site Inspection Facility is the national test bed for perimeter and portal monitoring technology and the prototype for the inspection portal that was recently installed in the USSR under the Intermediate-Range Nuclear Forces accord. The articles in the special issue of Sundiu Technology describe some of our current contributions to verification technology. This work supports the US policy to seek realistic arms control agreements while maintaining our national security.
The Department of Energy sponsored a workshop on the use of burnup credit in the criticality design of spent fuel shipping casks on February 21 and 22, 1988. Twenty-five different presentations on many related topics were conducted, including the effects of burnup credit on the design and operation of spent fuel storage pools, casks and modules, and shipping casks; analysis and physics issues related to burnup credit; regulatory issues and criticality safety; economic incentives and risks associated with burnup credit; and methods for verifying spent fuel characteristics. An abbreviated version of the DOE workshop was repeated as a special session at the November 1988 American Nuclear Society Meeting in Washington, DC. Each of the invited speakers prepared detailed papers on his or her respective topic. The individual papers have been cataloged separately.
The goals of our Basic Energy Sciences (BES) Materials Science Program at Sandia are: (1) Perform basic, forefront interdisciplinary research using the capabilities of several organizations. (2) Choose programs broadly complementary to Sandia's weapons laboratory mission, but separably identifiable. (3) Perform research in a setting which enhances technological impact because of Sandia's spectrum of basic research, applied research and development engineering. (4) Use large, capital-intensive research facilities not usually found at universities. The BES Materials Science program at Sandia Albuquerque has the central theme of Scientifically Tailored Materials. The major objective of this program is to combine Sandia's expertise and capabilities in the areas of solid state sciences, advanced atomic-level diagnostics, and materials-processing science to produce new classes of tailorable materials for the US energy industry, the electronics industry and for defense needs. Current research in this program includes ion-implantation-modified materials, physics and chemistry of ceramics, tailored surfaces for materials applications, strained-layer semiconductors, chemical vapor deposition, surface photo kinetics, organic and high-temperature superconductors, advanced growth techniques for improved semiconductor structures and boron-rich very high temperature semiconductors.
The Annual Solar Thermal Technology Research and Development Conference is being held at the Holiday Inn Crowne Plaza in Arlington, Virgina, Marh 8 and 9, 1989. This year the conference is meeting in conjunction with SOLTECH '89. SOLTECH '89 is a jointly sponsored meeting of the Solar Energy Industries Association, Interstate Solar Coordination Council, Sandia National Laboratories and the Solar Energy Research Institute. This report contains the agenda, extended abstracts and most significant visual aids used by the speakers during the Solar Thermal Technology research and development sessions. The program is divided into three sessions: Solar Electric Technology, Non-Electric Research and Development and Applications, and Concentrators.