Publications

The Precision Linear Shaped Charge (PLSC) design concept involves the independent fabrication and assembly of the liner (wedge of PLSC), the tamper/confinement, and explosive. The liner is the most important part of an LSC and should be fabricated by a more quality controlled, precise process than the tamper material. Also this allows the liner material to be different from the tamper material. The explosive can be loaded into the liner and tamper as the last step in the assembly process rather than the first step as in conventional LSC designs. PLSC designs are shown to produce increased jet penetrations in given targets, more reproducible jet penetration, and more efficient explosive cross-sections using a minimum amount of explosive. The Linear Shaped Charge Analysis Program (LSCAP) being developed at Sandia National Laboratories has been used to assist in the design of PLSCs. LSCAP predictions for PLSC jet penetration in aluminum targets, jet tip velocities and jet-target impact angles are compared to measured data. 8 refs., 19 figs., 1 tab.

Current work in the area of integrated materials monitoring/tracking and accounting at Argonne National Laboratory-West (ANL-W) has resulted from the development of materials accounting system by Los Alamos National Laboratory (LANL) and a demonstrated personnel and materials tracking system by Sandia National Laboratories (SNL). The integration of these two systems has culminated in the current system effort which is called the ARGonne Unified Safeguard (ARGUS) system. The ARGUS system is made up of three major components. These components perform the functions of observing all container movements, authorized materials access approval, initiation and receipt of materials transfers, and perform materials accounting for the facility. ARGUS system benefits can be summarized through system capabilities as follows: near real-time accountability, full traceability of materials access and transfer, enforcement of approved personnel access to materials, electronic confirmation of materials surveillance procedures during materials access and transfers, continuous surveillance of all material not directly involved in the manufacturing process, transfer and receipt, and automatic notification to security for identified anomalies. This paper will concentrate on the overall ARGUS system, its operational impacts and advantages. 2 refs., 2 figs.

An Optimal Projection reduced order controller is designed and implemented on an experimental controlled structure testbed. Twenty modes of the test structure lie within the controller bandwidth. Four strain sensor signals are fed back through an eighteenth order dynamic controller into four stress actuators (not collocated with the sensors) to reduce the vibration of the structure. Five independent performance measures are simultaneously minimized with an Optimal Projection controller derived from a 58th order state space model. The controller reduces the RMS vibration response by up to 65% without saturating the actuators and without destabilizing high frequency modes. The Optimal Projection controller always performs better than a sub-optimal controller based on ordinary Linear Quadratic Gaussian theory. The homotopy algorithm used to solve the Optimal Projection synthesis equations is described, and both analytical and experimental results are presented. 26 refs., 6 figs., 5 tabs.

The unsteady thin-layer Navier-Stokes equations for a perfect gas are solved with a linearized block Alternating Direction Implicit finite-difference solution procedure. Solution errors due to numerical dissipation added to the governing equations are evaluated. Errors in the numerical predictions on three different grids are determined where Richardson extrapolation is used to estimate the exact solution. Accurate computational results are tabulated for the hypersonic laminar flow over a spherical body which can be used as a benchmark test case. Predictions obtained from the code are in good agreement with inviscid numerical results arid experimental data.

The Solar One Pilot Plant successfully demonstrated the feasibility of solar central receiver power plants. During its operating years much data were collected regarding the efficiency and availability of the various plant systems. This paper summarizes these statistics and compares them to goals developed by the Department of Energy. Based on this comparison, design and operation improvements are recommended so that future central receiver plants can more closely attain these goals. 9 refs., 4 figs., 1 tab.

This paper explores the relative contributions of radiative and convective heat transfer to objects in large pool fires. The partitioning process depends on many factors. Results include measurements of the temperature of the objects in the fire, the flames surrounding the object, the total heat flux to the objects and the radiative component of the heat transfer at a few locations using transpiration radiometers. These measurements will be compared with calculations. Agreement between the measured radiative heat flux and the calculated radiative heat flux is good. The convective contribution was calculated from the total and radiative parts and was found to be from 10--20% of the total. 18 refs., 18 figs.

28C256 EEPROM total dose and dose-rate results are presented. Mode dependent total dose failure occurred at 9.5 krad(Si) when writing and 33 krad(Si) when reading. Average upset and latch-up thresholds were 3.8 /times/ 10/sup 8/ rad(Si)/s and 7.7 /times/ 10/sup 8/ rad(Si)/s, respectively. 3 refs., 5 tabs.

Development of the Advanced Small Site Program (ASSP) will satisfy the requirement for a small to medium sized security system uses commercially available, low cost, state-of-the-art technology to enhance its performance. The system addresses all aspects of technical security. These aspects include control and display; perimeter and interior sensors; data and video transmissions; video assessment; reduced installation, operation, and maintenance costs. Major system features include use of multi-level graphics with touchscreen inputs to control all sensor and video functions. An optional feature allows the use of fiber optics for data or video transmissions. Integration of functional components into modular sub-systems eases the task of expanding, maintaining, and operating the system. The system's automatic restart function permits a fully loaded system to configure itself in less than ten minutes. Site personnel will be able to create and modify a configuration data file of the site. The ASSP software uses this file data to run its programs. The configuration file contains the number of sensors, sectors, buildings, cameras, sensor thresholds, sensor priorities,and other site specific information. An off-line program obtains this information through a series of queries to the site personnel. This information is written to a data configuration file. This paper describes the functions and integration of this system. 11 figs.

Our division is charged with instrumentation development in support of underground testing. We find it necessary to be able to evaluate the performance of waveform digitizing systems with sampling rates from a few kilohertz to more than a gigahertz. We have been developing an integrated system which can provide quantitative results on the performance of systems and subsystems. Here we describe a system which is controlled by a Microvax II with instrumentation control through the IEEE-488 buss. The evaluation procedures are aimed at being consistent with a new Trial Waveform Digitizer Standard generated by the Waveform Measurements and Analysis committee appointed by the Instrumentation and Measurement Society of IEEE. This standard has been recently accepted by the IEEE and will be published in the next few months. Attention is given to the accurate measurement of effective-bit performance and differential nonlinearity of waveform digitizers. 3 refs., 14 figs.

Static and dynamic analyses of an impact limiter for a spent fuel cask have been performed using the finite element analysis code PRONTO2D (Taylor and Flanagan, 1987). The impact limiter contained wood as the energy absorbing material, with the wood confined by a cylindrical metal outer skin and sixteen metal stiffeners (gussets). The object of these analyses was to determine how the wood interacts with the metal stiffeners and to determine if the impact limiter would behave differently under static versus dynamic loading conditions. Originally, the metal gusset strength was assumed to be limited by the elastic buckling load. Further analysis showed that the gusset strength was not limited to the elastic buckling load and that each gusset contributed significantly to the impact limiter's strength. The current analyses investigated the strength of a flat plate or gusset used in impact limiter systems. 3 refs., 6 figs.

A two-dimensional synthetic aperture radar (SAR) phase correction algorithm is described as a natural extension of a one-dimensional technique developed previously. It embodies many similarities to phase gradient speckle imaging and incorporates improvements in phase estimation. Diffraction limited performance has been obtained on actual SAR imagery regardless of scene content or phase error structure. The algorithm is computationally efficient, robust, and easily implemented on a general purpose computer or special purpose hardware. 13 refs., 1 fig.

We describe a Silicon-on-Insulator (SOI) structure for high voltage BICMOS uniquely suited to the use of porous silicon (PS). In this SOI structure, bulk, high speed bipolar devices are readily integrated with CMOS high voltage and logic devices (smart power). To investigate the processing compatibility of PS with this structure, we measured breakdown strength and etch rate of thermally treated PS in 7:1 buffered oxide etch (BOE) and determined that they can approach values typical of thermal silicon oxides/nitrides. 7 refs., 2 figs.

The solidification behavior of Alloy 718 and other Nb-bearing austenitic superalloys has been examined using an integrated analytical approach. All alloys of this type begin solidification with the formation of Nb-lean austenitic dendrites. Interdendritic eutectic-type solidification constituents involving MC-type carbides and a Nb-rich Laves phase occur in these alloys. The ..gamma../Laves eutectic constituent terminates solidification in these alloys. Nb is the dominant element in the evolution of solidification microstructure with C and Si affecting the amounts of ..gamma../MC and ..gamma../Laves constituent observed. Simple solidification models predict reasonably well the amount of eutectic constituent observed. 11 refs., 9 figs., 2 tabs.

An entry control system (ECS) allows the movement of authorized personnel and material through normal routes while detecting and delaying movement of unauthorized personnel and contraband. This paper presents an overview of several unique design and operating principles used in the implementation of a positive identity entry control system utilizing proximity cards. The system design incorporates distributed processing to support geographically separated entry points and redundancy such that no single point failure will shut down operations. The functionality and integration of the photo identification system, the visitor authorization system, and the access control and contraband detection systems will be discussed. Systems unique features such as temporary badge issue for lost or forgotten badges at entry points using video lookup, visitor processing, and ergonomic and environmental considerations for the design of the proximity card based entry lane will be covered. 6 figs.

Effective implementation of an insider protection program in light of the new directives can be accomplished through sound planning and a strong management commitment to meaningful improvements. Good planning, with a firm set of goals and objectives that have reasonable milestones, are essential elements in the effective implementation of new requirements. This paper describes a structured approach to achieving effective and acceptable program implementation.

Analysis of the electrohydrodynamic (EHD) equations of motion of a planar liquid-lithium surface in the presence of a normal electric field suggest that liquid lithium may provide a large-area ion source for intense ion-beam diodes. Such sources are being developed for the Particle Beam Fusion Accelerator II at Sandia National Laboratories. In this paper, theoretical and experimental studies of the planar EHD ion source will be reviewed. When a planar liquid surface is subjected to an electric field of sufficient magnitude, EHD instabilities produce an array of cusps on the surface. The electric field enhancement at the apex of each cusp is sufficient to permit field evaporation of ions. The time delay between application of the electric field and ion emission depends on the magnitude and rate of increase of the applied electric field, and on the initial amplitude of the surface perturbation. Above 10 MV/cm, theory indicates that field emission will occur on a nanosecond time scale and that the characteristic spacing of emitters will be less than one micrometer. At these fields, the source should have an intrinsic divergence of less than 6 mrad and the effects of space charge from neighboring emitters should not inhibit emission significantly. Experimental measurements of wavelength and cusp-formation-times for water and ethanol at electric fields near the critical field for instability have agreed well with theory. 11 refs., 4 figs.

Unlike small (localized) bipolarons, large (mobile) bipolarons can yield bipolaronic superconductivity. The stringent conditions for the formation of large bipolarons as well as distinctive features of the normal-state transport and superconducting-state properties of large bipolarons appear consistent with observations of the high-temperature superconductors. © 1989.

The realization that structures in Nature often can be described by Mandelbrot's ''fractals'' has led to a revolution in many areas of physics. The interaction of waves with fractal systems has, understandably, become intensely studied since scattering is the method of choice to probe delicate fractal structures such as chainlike particle aggregates. Not all of these waves are electromagnetic: neutron scattering, for example, is an important complementary tool to structural studies by x-ray and light scattering. Since the phenomenology of small-angle neutron scattering (SANS), as it is applied to fractal systems, is identical to that of small-angle x-ray scattering (SAXS), it falls within the scope of this Working Paper. 9 refs.

Sandia National Laboratories, in conjunction with its participation in the American National Standards Institute (ANSI) writing groups, has undertaken to provide an experimental and analytical basis for the design of components of radioactive materials packages to resist normal transport shock and vibration loads. Previous efforts have resulted in an overly conservative shock spectra description of the loads in the tie-downs and cask attachment points anticipated during normal shipment. The present effort is aimed at predicting the actual loads so that the design basis can be accurately determined. This goal is being accomplished with road simulator and over-the-road tests and the development of an analytical model. This model is used to parametrically evaluate and envelop the transportation systems' responses. The parameters to be varied include damping, stiffness, geometry, and cargo mass. The over-the-road tests provide operational data that are used to validate the selection of environments for the road simulator tests. The road simulator tests provide verification for the model. This verification is accomplished since the road simulator tests provide not only the system response which can be measured in over-the-road tests but also the system input. Finally, when the model has been verified, it can be used to vary parameters to envelop a wide range of normal transport conditions.

Sandia National Laboratories has developed a variety of command, control, and display systems for a broad spectrum of users. This paper briefly describes the latest systems developed for the Department of Energy (DOE), the Department of Defense (DOD), and the Department of State (DOS) applications. Applications covered vary from relatively small facilities to large complex sites. 3 refs., 6 figs.

Novel methods/techniques for the detection of explosives are briefly described. The methods include vapor detection, preconcentrators, chemiluminescence detectors and microwave detectors. (CBS)

An inherent aspect of active array radars is the use of large numbers -- typically hundreds -- of transmit/receive (T/R) modules. The implementation of this technology at Sandia has created new challenges for the tester designer. Foremost among these challenges is the need to design T/R module testers which can accommodate such large numbers of devices-under-test (DUTs). This task is complicated by the fact that state-of-the-art T/R modules are extremely sophisticated and require a broad spectrum of tests for adequate evaluation. The Sandia T/R module operates in Ku band and consists of a transmitter, receiver, programmable phase shifter, programmable attenuator, modulator, switched limiter, and gate-array controller. The programmable phase shifter is common to both the transmitter and receiver, but the attenuator is unique to the receiver. The instruments required for the tests include a network analyzer, a spectrum analyzer, a noise figure meter, a peak-power meter, and an automated tuner system. The key to a successful tester is in integrating all of the above instruments such that the desired measurements can all be performed from a single, two-port, tester-to-DUT connection. The natural consequence of such a design is that some measurements will have to be de-embedded from the integrated test setup. This paper addresses both the tester's instrument integration and the resulting de-embedding concerns. 2 figs.

In the past several years a wealth of decay data has been obtained and reported, much of it in ''Decay Data of the Transactinium Nuclides'', IAEA Technical Reports Series No. 261 (1986). The decay data for the daughters of /sup 238/U have been notable by their absence in such compilations; and since there is a need for such data, a set of experiments has been performed to measure the gamma-ray emission probabilities. Uranium samples of known mass and isotopic concentration in aqueous solution are analyzed with a high-purity germanium gamma-ray spectrometer. Various samples have also in solution multi-line calibration sources with well-known relative intensities. The well-known emission probabilities of the /sup 235/U gamma rays are used to provide an absolute intensity reference. Since self-absorption of the sample is included in the effective detector efficiency, there is not need for a separate calculation of this absorption. Gamma-ray emission probabilities for the energy range 63 to 1938 keV are reported. Sources of error, including those in the efficiency curve, are discussed. 11 refs., 5 figs., 4 tabs.

Thirty-nine (39) bipolar device lots (195 devices) were tested for peak photocurrent. Difference in average photocurrent between lots of same device types was less than a factor of three in all cases. 4 figs.

Lot acceptance tests are evaluated for nonhardened CMOS devices for low total-dose space applications. Examples are presented for cases in which gate- or field-oxide leakage dominates device response. 12 refs., 3 figs.

Spent fuel transportation casks have arrived at final destinations with removable surface contamination levels in excess of regulatory limits, although pre-transport surveys indicated removable contamination levels were well below these limits. The control of this in-transit ''weeping'' of surface contamination on pool-loaded spent fuel transport casks is of particular concern to both the US Department of Energy (DOE) and the US Nuclear Regulatory Commission (NRC). Weeping, also known as sweating, is the transformation of fixed radioactive particulates on an exterior surface of transport cask to a removable state. Weeping has been observed sometime after a cask is removed from a fuel pool and decontaminated. The weeping phenomenon is countered by time-consuming operational constraints and procedures which have a significant impact on cask turnaround times and occupational exposures at transport facilities. Further, the arrival of a contaminated cask results in negative public perceptions that are inconsistent with DOE and NRC goals. The objectives in resolving the technical issue of weeping are to identify specific causes of the weeping phenomenon, then to implement new cask design requirements and supporting operational procedures which will limit or inhibit the accumulation, retention, and in-transit conversion of fixed surface contamination. 6 figs., 1 tab.

To protect a security instrument such as a television camera from subversion by signal substitution, the data from the instrument are digitized and submitted to an authenticator. The digital data may then be transmitted in the clear over a non-secure medium. Appended to the data is a 10-bit authentication value based on the values of the data and a random authentication number. At the receiving end, the data are submitted to an identical authenticator. If it produces the same authentication value, the data are authentic. Such a scheme can only work if the instrument, the authenticator, and the link between them can be protected from tampering. This paper describes a tamper resistant container designed to protect a data authenticator and television camera against an adversary having sophisticated resources and complete design information. The container's design includes active elements to detect and report intrusion attempts in real time. It also includes passive elements to indicate upon later inspection that the container had been violated. 1 ref., 2 figs.

Considerable interest has been generated within the past several years concerning the use of new generation video motion detection (VMD) systems as exterior intrusion sensors. The new generation VMD systems advertise advanced video signal processing techniques and algorithms which are aimed at rejecting nuisance alarm sources inherent to the uncontrolled exterior environment. Older generation VMD systems used in an exterior environment tend to have high nuisance alarm rates. The high nuisance alarm rates of the older systems made them generally unacceptable for use as an exterior sensor. This paper discusses the results of continued field testing of new generation VMD systems. Field tests were conduced in an exterior perimeter zone application and an application looking at the exterior entrance of a building. Test results include each VMD system's detection capabilities and nuisance alarm characteristics for each particular application. Also site considerations such as lighting, cameras and zone layouts for exterior video motion detection are discussed. 1 ref., 14 figs., 1 tab.

The piezoelectric polymer, polyvinylidene di-fluoride (PVDF or PVF2), properly processed by the proprietary Bauer technique, is a material for a transducing element that can be used for a wide variety of stress, pressure, or temperature related measurements. Its versatility as a sensor requires especially careful attention to the special requirements for associated gauge packaging, installation, signal conditioning, recording, and analysis that are imposed by the particular diverse test conditions. Most applications reported to date have been for tests performed under laboratory conditions. But, the PVDF sensor has also been successfully used for stress wave measurement under adverse and often hostile field test conditions that require the use of lengthy transmission lines and allow only limited recording capability. This paper discusses one crucial aspect of field application -- measuring system characterization, and correction of signals distorted by systems of marginal frequency capability. 11 refs., 7 figs.

Radiation effects on polymers in the presence of air are characterized by complicated phenomena such as dose-rate effects and post-irradiation degradation. Most applications of polymeric materials in radiation environments involve air atmospheres. Taking account of oxidation effects and time-dependent phenomena is a necessity for understanding materials changes which occur during aging, and for dealing with issues of materials lifetime prediction, aging monitoring, materials selection, and material stabilization. Time-dependent radiation-degradation effects can be understood mechanistically in terms of: (1) features of the free radical chain-reaction chemistry underlying the oxidation, and (2) oxygen diffusion effects. A profiling technique has been developed to study heterogeneous degradation resulting from oxygen diffusion, and kinetic schemes have been developed to allow long-term aging predictions from short-term high-dose-rate experiments. These methodologies have been successfully applied for predicting degradation rates of a number of different materials under ambient nuclear environments. Low molecular weight additives which act either as free-radical scavengers or else as energy-scavengers are effective as stabilizers in radiation-oxidation environments. Non-radical oxidation mechanisms, involving species such as ozone, can also be important in the radiation-oxidation of polymers. 14 refs., 13 figs.

A comprehensive stress analysis was performed for a bimaterial plate subjected to a uniform change of temperature. The steel and brass portions of the specimen were bonded along a common edge. Whole-field measurements were made by high-sensitivity moire interferometry. A companion finite element numerical analysis of a similar body was conducted to help interpret the experimental results. The experiments documented a strong free-edge effect along the entire perimeter of the joint, an effect akin to a line singularity along the perimeter. High stresses in the edge-effected zone were determined from measurements, and enormous stress gradients were deduced by analysis. The largest stresses were found at the corner, where two edge-effected zones intersected. 5 refs., 8 figs.

Advanced titanium-aluminum intermetallic alloys (often simply called titanium aluminides) have certain properties which make them potentially attractive as advanced aerospace alloys. In order to utilize these alloys in engineering applications, it is necessary to process the alloys in a variety of ways including casting, hot forming and welding. All of these processes modify the microstructure of the alloy, which in turn directly influences the properties. The key to optimizing the alloy's properties is to control the microstructure by careful control of the processing parameters. Control for the microstructure requires a thorough understanding of the evolution of the microstructure, including elemental partitioning between the various phases which form in the alloy. Analytical electron microscopy (AEM) is an ideal way to characterize the microstructures on a fine spatial scale. Such high spatial resolution microanalysis is required to understand the microstructural evolution in these alloys. In this case, the alloy is a Nb modified Ti/sub 3/Al, and the partitioning behavior of interest is between a variety of ternary phases which are produced as a function of alloy cooling rate from a single homogeneous high temperature ..beta.. phase. The Nb is added to the alloy to enhance its performance, primarily through an improvement in ductility. In this work, the details of the procedure for quantitative analysis of these alloys are presented.

An applied B-field ion diode on PBFA II has produced a 17 TW proton beam for investigation of beam generation and transport physics pertinent to inertial confinement fusion experiments. Power was fed to the diode via two conical self-magnetically-insulated transmission lines that incorporated plasma opening switches. The diode utilized a pair of B-field coils in disc shaped cathodes to produce a 3 T axial B-field that insulated the 16 mm anode-cathode gap from electron loss. The 15-cm-radius anode was configured with a 5.5-cm-tall curved ion emitting region. A 2.6 MA ion beam originated from this region, was accelerated to 6 MV in the anode-cathode gap, and then transported ballistically toward the axis in a current neutralizing gas cell. The best transport (75%) occurred with narrow 5.5-cm-tall anode sources in which a 180 kJ proton beam was observed within 1.2 cm of the diode centerline. The FWHM of the beam focused at the centerline of the diode was 5 to 7 mm. This beam gave a peak proton power density of approximately 5 TW/cm/sup 2/. 12 refs., 8 figs.

The finite control volume method (FCVM) was successfully used to calculate both laminar and turbulent buoyancy driven flow of air in a square enclosure for Ra = 10/sup 3/ to 10/sup 8/. For laminar flow, comparisons of the computed solution with both experimental data and other numerical solutions are in excellent agreement. Comparisons of selected velocities and average Nusselt numbers with a ''benchmark'' solution presented by deVahl Davis are consistently within 4%. For turbulent flow, the agreement with another numerical solution is generally good, considering the large difference in the number of nodes employed. The agreement with extrapolated experimental correlations for the average Nusselt number was acceptable. 20 refs., 4 figs., 2 tabs.

Magmatic activity, and particularly silicic magmatic activity, is the fundamental process by which continental crust forms and evolves. Drilling in the Inyo Chain, a 600-year-old chain of volcanic vents in California, has shown the close relationship of silicic eruption to shallow dike emplacement, the control of eruptive style by shallow porous-flow degassing, the origin of obsidian by welding, the development of igneous zonation by viscosity segregation, and the character and size of conduits in relation to well- understood magmatic and phreatic eruptions. Planned drilling at the site of the largest eruption of the century, in the Mt. Katmai region of Alaska, will test models for explosive eruptions, elucidate the process of vapor-transport of metals, and provide the first measurements of rates of cooling and chemical alteration in a relatively simple, non-composite igneous system. -Author

To overcome the heat deficit and oxidizing atmosphere problems and to reduce fuel consumption, a small gas forge furnace has been developed which incorporates recuperative heating; as the combustion air is drawn into the furnace it is preheated by passing it through a simple heat exchanger which is heated by the exhaust gases from the furnace. This recuperative heating principle is the same used by blast and open hearth furnaces but they typically employ complex heat exchangers, and extensive blowers and valving to direct the flow of the intake and exhaust gases. In the furnace described in this article a chimney is provided at the rear of the furnace and the air intake ducts pass through the chimney before reaching the venturi where the fuel gas is injected. Thermocouples were place in the air intake ducts and the temperature of the recuperated air was 1000 F. Based on data in the Mechanical Engineers Handbook (Industrial Heating Furnaces) fuel savings are directly related to the temperature of the preheated air. The theoretical saving in fuel with 800 F. combustion air is about 19%. The furnace is very quiet, since no blowers are used and the venturi is located in the center of a long tube. To control the furnace atmosphere and to help reduce heat loss, a close fitting swing away door has been incorporated, and the entire furnace is insulated with lightweight high performance ceramic insulation. The resulting furnace easily achieves forge welding temperatures, has an oxygen depleted atmosphere and has proven to be very effective and capable for small machine and hand forging operations. 6 figs.

Need for standardization has been discussed for years by many government agencies. In the past, every perimeter site upgrade resulted in the design, specification, procurement, and fabrication of a unique power and signal junction box. To save design and specification cost, a standard terminal panel and uninterruptible power supply (UPS) design for an exterior intrusion sensor detection system was developed for a security system within the Sandia National Laboratories complex at Albuquerque, New Mexico. In facilitating this requirement a design was sought that could easily be modified for other government or commercial applications and one that could easily be fabricated in the shop. Also of primary importance was the need for lightning protection for both the communications and voltage sources. A 12V dc UPS with a current capacity of up to 4 amperes complements the standard terminal design and allows uninterrupted sensor operation for a number of hours should the primary ac source be interrupted. This report encompasses the features of the designs. The designs are also being used and continuously evaluated in Sandia's Area III exterior test field. 7 figs.

Radiation effects on polymers in the presence of air are characterized by complicated phenomena such as dose-rate effects and post-irradiation degradation. These time-dependent effects can be understood in these terms: (1) features of the free radical chain-reaction chemistry underlying the oxidation, and (2) oxygen diffusion effects. A profiling technique has been developed to study heterogeneous degradation resulting from oxygen diffusion, and kinetic schemes have been developed to allow long-term aging predictions from short-term high dose-rate experiments. Low molecular weight additives which act either as free-radical scavengers or else as energy-scavengers are effective as stabilizers in radiation-oxidation environments. Non-radical oxidation mechanisms, involving species such as ozone, can also be important in the radiation-oxidation of polymers. 18 refs., 15 figs.

Introduced in 1951 and 1966 respectively, the field ion microscope and atom-probe mass spectrometer can hardly be considered new or emerging microprobes. Over the years, the ability to use these instruments to examine the structure and composition of various materials at the atomic level has been well established. However,recent advances in more conventional microanalytical techniques, particularly progress toward a higher degree of spatial resolution, has created renewed interest in all techniques capable of analysis on a very fine scale. Also, there has been an increased emphasis over the past several years in the application of the field ion microscope and atom-probe to problems of greater general interest in surface and materials science. It is therefore not totally inappropriate to discuss the field ion microscope and atom-probe within the context of ''emerging'' microprobes. The intent of this paper is to familiarize the reader with the techniques of field ion microscopy and atom-probe mass spectroscopy and describe several recent applications which demonstrate some of their unique attributes. 45 refs., 8 figs.

This paper reviews several techniques available to the experimenter to characterize the mechanical properties of near surface layers of engineering materials. The test methods examined are: micro-tensile testing, bulge testing, ultra-low load indentation testing, and microfabricated test structures. The applicability of these techniques as well as their advantages and difficulties are examined. Special emphasis is given to recent developments in ultra-low load indentation testing and microfabricated test structures. 61 refs., 2 figs.

The Department of Energy (DOE) established the seals task force in 1986 to scope the extent of seals problems, develop guidelines and criteria, and recommend improvements. Recent task force activities have been to update the Safeguards Seals Reference manual produced in 1986, lay the groundwork for seal standardization, and make recommendations for general and specific seals problems in the field. This paper will discuss the manual updates and other general task force activities. 5 refs.

For years the lighting industry has manually entered and manually performed calculations on the photometric data that is necessary for lighting designs. In the past few years many lighting manufacturers and private lighting design software companies have published computer programs to enter and perform these calculations. Sandia National Laboratories (SNL), and other interested organizations, are involved in outdoor lighting designs for Closed Circuit Television (CCTV) that require lighting design software programs. During the period when no commercial lighting design software programs existed, SNL first used a government agency's program and then developed an in-house program. The in-house program is very powerful but has limitations, so it is not feasible to distribute it to interested organizations. This program has been used extensively for many high security outdoor lighting design projects. There is still a demand for lighting design programs, so SNL has ordered several that are commercially available. These programs are being evaluated for two reasons: (1) to determine if their features are adequate to aid the user in lighting designs, and (2) to provide that information to SNL and other organizations. The information obtained in this paper is to be used to help an end user decide if a program is needed, and if so, to choose one. This paper presents the results of evaluations performed. 5 refs., 6 figs., 3 tabs.

Rigid, closed-cell, polyurethane foam is used in impact limiters in nuclear waste transport containers. During a hypothetical nuclear waste transport accident, the foam is expected to absorb a significant amount of impact energy by undergoing large inelastic volume reductions. Consequently, the crushing of polyurethane foams must be well characterized and accurately modeled to properly analyze a transport container accident. At the request of Sandia National Laboratories, a series of uniaxial, hydrostatic and triaxial compression tests on polyurethane foams were performed by the New Mexico Engineering Research Institute (NMERI). The combination of hydrostatic and triaxial tests was chosen to provide sufficient data to characterize both the volumetric and deviatoric behaviors of the foams and the coupling between the two responses. Typical results from the NMERI tests are included in this paper. A complete description of these tests can be found in Neilsen et al., 1987. Constitutive models that have been used in the past to model foam did not capture some important foam behaviors observed in the NMERI tests. Therefore, a new constitutive model for rigid, closed-cell, polyurethane foams was developed and implemented in two finite element codes. Development of the new model is discussed in this paper. Also, results from analyses with the new model and other constitutive models are presented to demonstrate differences between the various models. 4 refs., 6 figs., 1 tab.

There are many Safeguards applications which have a need for a reliable system that uses state-of-the-art processing techniques to detect and track targets moving through a scene. A general purpose Target Cueing and Tracking System (TCATS), which is independent of the application and the user interface, is under development. The TCATS algorithms were developed and evaluated with commercially available image processing boards and a VME bus based microcomputer. The TCATS algorithms have successfully demonstrated a high detection capability and the ability to ignore exterior environmental conditions, such as cloud shadows moving through the scene, snow, blowing dust, rain, and moderate camera motion. These algorithms remove camera motion. These algorithms remove camera motion and perform target detection and tracking at near real time. The algorithms can handle many targets and retain the identity of each object from one frame to the next. Special ruggedized hardware is also under development to reduce the size, cost, and power consumption, and to increase the processing rate, reliability, and environmental operating capability of the TCATS. Field evaluations are underway specifically for Exterior Fixed Site Security applications. Testing includes nuisance alarm data gathering and detection capability evaluation of human targets crossing perimeter zones. This paper describes the detection and tracking techniques, custom hardware, and future development plans for the TCATS. 5 refs., 9 figs.

The Outsider Analysis (Outsider) module is part of the Analytic System and Software for Evaluation of Safeguards and Security (ASSESS). Outsider and the ASSESS Facility Descriptor (Facility) module together supercede the Systematic Analysis of Vulnerability to Intrusion (SAVI) PC software package. Outsider calculates P(I), the probability that outsiders are interrupted during an attack on a facility by security forces at the facility, and P(W), the probability of security system win. SAVI exhaustively examines every possible path to find the ten most vulnerable paths. Exhaustive search is adequate if the number of paths to examine is small, but moderately complex facilities can have millions of paths, making exhaustive search too slow for practical purposes. Outsider has two new algorithms that generate paths in order of vulnerability, finishing in a fraction of the time required by SAVI. The new Outsider algorithms make containment analysis easier for analysts than ever before. We describe the new algorithms and show how much better they perform than the SAVI exhaustive search algorithm. 6 refs., 5 figs., 2 tabs.

This paper demonstrates the use of the Analytic System and Software for Evaluating Safeguards and Security. ASSESS is an integrated approach for evaluating the effectiveness of safeguards against theft of special nuclear material by different types of adversaries: insiders, outsiders, and colluding insiders and outsiders. ASSESS consists of six modules: System Manager, Facility Descriptor, Insider Analysis, Outsider Analysis, Neutralization Analysis, and Collusion Analysis. This paper introduces the modules, describes their scope, and highlights the interactions among them. Separate papers will provide detailed discussion and demonstration of each of the modules. The ASSESS code runs on the IBM PC family of computers with 640K RAM, the DOS operating system, and Microsoft Windows. The Windows environment provides a very efficient and convenient graphics user interface as well as drivers for many types of output devices. ASSESS is being developed jointly by Lawrence Livermore National Laboratory and Sandia National Laboratories under the sponsorship of the Department of Energy (DOE) Office of Safeguards and Security. The first version of the ASSESS code was delivered to DOE/OSS in March 1989. 7 refs., 4 figs.

Historically, large scale safeguards alarm and communication systems have required the expensive computational power of a mainframe of midsize computer. Due to the widespread availability and reduced cost of PC-based technology, this class of machine is a much preferred solution. This paper will discuss a development program integrating this technology with inexpensive local area network (LAN) hardware to support (1) many touch panel based operator graphics consoles, (2) redundant LAN communications, (3) fault-tolerant LAN communication, (4) redundancy in subsystem failure, (5) modularity in design, (6) fault-tolerant video communication, (7) inexpensive PC-based video annotation and switcher design, (8) inexpensive video replay capability, (9) use of fiber optic communication media, (10) distributed parallel processing, and (11) minimized overall system cost. The Intel BitBus architecture was selected for network communications between PC CPUs. The network supports both fiber optic and copper media and insures message integrity/receival. Custom boards have been developed to transform PCs modular expandable routing switchers with video presence detection and annotation. 1 fig.

The Outsider Analysis (Outsider) module is part of the Analytic System and Software for Evaluating Safeguards and Security (ASSESS). Outsider and the ASSESS Facility Descriptor (Facility) module together supersede the Systematic Analysis of Vulnerability to Intrusion (SAVI) software package. Outsider calculates P(I), the probability that outsiders are interrupted during an attack by security forces at the facility, and P(W), the probability of security system win, and has other features not found in SAVI. Analysts can select intruders from a set of ten reference threats, ranging from well-equipped terrorists to intruders with no equipment at all. New analysis algorithms run 60 to more than 100 times faster. New reports detail how safeguards are defeated at each element in a path and give other data critical to effective upgrade decisions. Outsider takes as input a facility security system defined in Facility and produces intermediate results for the ASSESS Collision module. 8 refs., 6 figs.

The feasibility of competitive, modular bulk electric power from the sun may be greatly enhanced by the use of a reflux heat pipe receiver to combine a heat engine such as Stirling with a paraboloidal dish concentrator. This combination represents a potential improvement over previous successful demonstrations of dish-electric technology in terms of enhanced performance, lower cost, longer life, and greater flexibility in engine design. There are, however, important issues and unknowns which must be addressed to determine engineering feasibility of these devices. In the pool boiler reflux receiver, concentrated solar radiation causes liquid metal (sodium or potassium) to boil. The vapor flows to the engine heater heads, where it condenses and releases the latent heat. The condensate is returned to the receiver absorber pool by gravity (refluxing). This is essentially an adaptation of heat pipe technology to the peculiar requirements of concentrated solar flux, and provides many advantages over conventional heated tube receiver technology. Boiling theory indicates that long-term stable boiling of liquid metal may be difficult to achieve. Laboratory scale experiments have been performed. Initial tests confirmed that boiling is unstable in a baseline boiler. Boiling stability was established after the addition of ''artificial cavities'' to the heated surface, and successful boiling of sodium was demonstrated for 100 hours. Other stabilizing influences may have been present, and will be discussed. The flux and geometry closely simulated a real receiver. The results of these tests are presented, along with the design of a full scale receiver for on-sun testing and considerations for long term operation. 15 refs., 10 figs.

Techniques are being developed to gain understanding of energy transport efficiencies through changes in pulsed power transmission line geometries. These techniques are being applied to design study of the PBFA-II accelerator which has the goal of increasing the energy available for ICF experiments. Transverse electromagnetic (TEM) wave analysis yields a simple circuit model of the new coax-to- parallel-plate transition. This simple model gives insight into the dominant physics of the device and suggests design improvements that will lead to the desired energy efficiencies. Insights gained by this simple model are confirmed and refined by 3-dimensional, time dependent computer simulations with the SOS code and scale model experiments. Simulations have predicted experimental results to high degree of accuracy which adds confidence in both the simulations and the scale model experiments. 1 ref., 11 figs., 1 tab.