Publications

With increasing demands on system requirements, designers must look for new alternatives to successfully complete their goals. One alternative that offers designers many benefits is ASICs. They maximize device functionality while minimizing system space. Also as operating frequencies approach gigahertz speeds, ASICs allow specialized placement of functional blocks on chip to minimize propagation delays of the signal. At Sandia, we found these requirements forcing us to look at ASICs fabricated in GaAs.

The supercomputer industry is at a crossroads. While its traditional markets have become relatively mature, the industry is becoming more competitive, especially with the challenge from Japan. The industry can either fight over this stable market or dramatically expand the market. The choice is obvious, but what are these new markets and how to approach them. This paper addresses these issues. First, it explains how the traditional definition of a supercomputer seriously constrains its market. An alternate definition opens up a much larger, emerging market. Second, it describes a market segmentation two barriers preventing customer in these new segments from using supercomputing and describes mechanisms to reduce and/or eliminate these barriers. Third, it discusses the portfolio analysis strategy to determine the markets in these new segments on which to concentrate. Obviously, parts of manufacturing are key targets. Finally, it draws some conclusions in terms of two scenarios -- one which describes a healthy, growing US supercomputer industry, the alternative showing the industry rapidly following the footsteps of the US consumer electronics industry. 6 refs.

Thin cathode coatings have been shown to be effective in suppressing pulsed breakdown in vacuum. Coatings are normally plastics, although some inorganics have been used. Thicknesses range from on the order of a micron to several mils (1 mil = 25.4 /mu/m). Pulse lengths from 10 ns to more than 1 /mu/s have been studied. 2 refs., 3 figs.

Data from an array of sixteen electric-field sensors have been used to evaluate the potential benefits to lightning warning systems of processing ''old'' data as well as data from off-site sensors. These specific topics are approached from a broad decision-theoretic viewpoint. 4 refs., 10 figs.

Low coulombic efficiencies of zinc/bromine redox batteries have been attributed to migration of bromine and negatively charged bromine moieties through the microporous separator used to separate the catholyte from the anolyte. While it has been demonstrated that improvements in coulombic efficiency can be achieved by replacing the microporous separator with a cationic ion exchange membrane, these membranes are expensive and/or not sufficiently conductive to be practicable. We have found that the rate of bromine permeation can be reduced by two orders of magnitude with minimal decreases in conductivity by impregnating commercial microporous polyethylene type separators with sulfonated polysulfone, a cationic polyelectrolyte that was developed in earlier work for other redox storage batteries. 5 refs., 1 fig., 1 tab.

The phenomenon of molten fuel-coolant interaction (FCI) is of considerable interest in many industrial processes where hot molten material may come in contact with water, including the pulp and paper, aluminum, steel, and nuclear power industries. The nature of the FCIs can range from mild film boiling, through energetic boiling, up to a violent vapor explosion. In the nuclear power industry, FCIs are of interest because of their possible consequences during hypothetical light water reactor core meltdown accidents. These interactions may occur under a variety of conditions either within the reactor vessel or in the reactor cavity. The IFCI computer code is being developed to investigate the FCI problem at large scale using a two-dimensional, four-field hydrodynamic framework and physically based models. IFCI will be capable of treating all major FCI processes in an integrated manner. The hydrodynamic method and physical models used in IFCI are discussed. Results from a test problem simulating a generic pouring mode experiment are presented. 39 refs., 10 figs., 1 tab.

Design and analysis of spacecraft power systems have been difficult to perform because of the lack of circuit level models for nonlinear inductive elements. This paper reviews some of the models which have been proposed, their limitations, and applications. An improved saturation dependent model will be described. The model has been implemented in SPICE and with a commercial circuit program and demonstrated to be satisfactory in both implementations. 3 refs., 9 figs.

Vibration testing in a centrifuge acceleration field (up to 50 gs) can be accomplished in either of two axes relative to the centrifuge acceleration with a modified, commercially available, electrodynamic shaker and the use of a specially designed orthogonal motion converter. Fixing the shaker armature axis in-line with the centrifuge arm (head towards the pivot) keeps the inertial forces on the head in the one direction which can be offset with servo controlled pneumatic bags located beneath the shaker head. Testing in an axis perpendicular to the principal axis is accomplished with the orthogonal motion converter which is driven by the shaker head. 13 figs.

For estimating the global elasto-plastic structural response of critical concrete structures subjected to an aircraft crash, the time dependent impact force of a flat rigid barrier against a normally impacting aircraft was first evaluated and then the response, to the impact force, was calculated. In this approach, a significant problem was to determine the impact force for the aircraft against a rigid target. A review of the method proposed to determine the impact forces showed that all were based on analytical methods. However, in these analytical methods, there were many assumptions and many questions remained to be answered. Because of the uncertainty involved in the analytical prediction of the impact force, a full- scale aircraft impact test was performed and an extensive suite of response measurements was obtained. In this paper, these measurements are analyzed to evaluate the impact force accurately. Also, the results were used to evaluate existing analytical methods for prediction of the impact force. 7 refs., 10 figs.

The hydrostatic pressure dependence of the /beta/ molecular relaxation process of polyvinylidene fluoride (PVDF) has been investigated to 20 kbar. This relaxation is known to have a strong influence on the electrical and mechanical properties of PVDF. The observed large slowing down of the relaxation process is discussed in terms of the Vogel/endash/Fulcher equation. There is an increase in both the energy barrier to dipolar motion and the reference temperature (T/sub 0/) for the kinetic relaxation process which represents the ''static'' dipolar freezing temperature for the process.

Whether upgrading or developing a security system, investing in a solid state video recorder may prove to be quite prudent. Even though the initial cost of a solid state recorder may be more expensive, when comparing it to a disc recorder it is practically maintenance free. Thus, the cost effectiveness of a solid state video recorder over an extended period of time more than justifies the initial expense. This document illustrates the use of a solid state video recorder as a direct replacement. It replaces a mechanically driven disc recorder that existed in a synchronized video recording system. The original system was called the Universal Video Disc Recorder System. The modified system will now be referred to as the Solid State Video Recording System. 5 figs.

Past experience in addressing the insider threat has led to the development of general principles for mitigating the insider threat while minimizing adverse impacts on site operations. Among the general principles developed was the requirement for real time tracking of personnel and material. A real time system for personnel and material tracking will aid in mitigating the insider threat by providing critical information regarding the movement and location of personnel and material. In addition, this system can provide an early detection mechanism for potential insider actions. This paper describes the development, operation, and performance of a technology-based system which utilizes radio frequency transmitters to achieve the real time tracking of personnel and material. The major elements of this system are personnel tracking credential which cannot be removed from an authorized individual without an alarm being sounded, and material control device which is utilized to control and monitor access to material. These elements form an insider protection system through the use of software which establishes the ''rules'' under which the system will operate. The performance of this system has been evaluated under both laboratory and operational settings in order to: (1) demonstrate the system's ability to successfully control access to material and areas by personnel, and (2) provide information regarding the status of materials in transit and storage. 3 refs., 1 fig.

The Nuclear Engineering Department of National Tsing Hua University organized a workshop on Severe Accident Management. The workshop was sponsored by Taiwan Power Company and was held at Taipei, Taiwan from July 31 to August 11, 1989. The topics covered in the workshop included the general in-vessel LWR severe accident phenomena, containment responses and performances under severe accident conditions, results of Level 1 PRAs of three Nuclear Power Plants at Taiwan, and also two lectures related to the NUREG-1150 report just published by US NRC. This presentation covers these two lectures.

Recent experiences in operating nuclear plants in the United States have demonstrated the need for an in situ cable condition monitoring technique that can assess whether installed, low-voltage, unshielded cables have local damage that could compromise their ability to function under normal and accident service conditions. This paper summarizes current US programs that have been initiated to develop a technological basis for monitoring cables with local degradation. 7 refs.

An axial flow turbine mass model has been developed and used to study axial flow turbines for space power systems. Hydrogen, helium-xenon, hydrogen-water vapor, air, and potassium vapor working fluids have been investigated to date. The impact of construction material, inlet temperature, rotational speed, pressure ratio, and power level on turbine mass and volume has been analyzed. This paper presents the turbine model description and results of parametric studies showing general design trends characteristic of any axial flow machine. Also, a comparison of axial flow turbine designs using helium-xenon mixtures and potassium vapor working fluids, which are used in Brayton and Rankine space power systems, respectively, is presented. 9 refs., 4 figs., 2 tabs.

Energetic fuel-coolant interactions may occur in a nuclear reactor in the event that molten fuel comes in contact with the reactor coolant water. Reliable mechanistic models of these interactions have yet to be developed and so relatively simple thermodynamic models have been proposed for estimating the conversion of thermal energy to mechanical work. The present paper outlines a generalized thermodynamic model for fuel-coolant interactions which accounts for variable thermodynamic properties as well as the effect of latent heat in the fuel. The variable property model is shown to provide an upper bound (most conservative) estimate of the conversion efficiency compared to other formulations appearing in the literature. 7 refs., 5 figs.

Unconfined heterogeneous two-phase detonations in liquid droplet-air mixtures are investigated. The liquid fuel is placed in a V-shaped channel and is dispersed into the atmosphere to form a cloud by an explosive detonating cord laid along the bottom vertex of the channel. An aerosol cloud 7 m high by about 1.5 m averaged width can be generated in this way with a typical mass ratio of fuel to explosive charge of 150. In the present study the length of channel used is typically 10 m giving a detonable fuel-air cloud of about 100 m/sup 3/. The propylene-oxide driver and the test fuel are disseminated simultaneously. Detonation in the propylene-oxide section is initiated by the sheet explosive and the detonation then transmits from this driver section into the rest of the cloud formed from the test fuel. For insensitive fuels requiring a larger cloud dimension, two parallel fuel troughs spaced 1.2 m apart are used. It is found that propylene-oxide and nitrated hydrocarbon fuels detonate quite readily. For the case of propylene-oxide, significant vaporization of the aerosol is observed prior to initiation so that detonation is essentially in the gas phase. 15 refs., 4 figs.

We find a strong correlation between the preirradiation 1/f noise of pMOS transistors and their radiation hardness. This suggests that current fluctuations may provide a useful, nondestructive probe of defects in MOS devices. 18 refs., 4 figs., 1 tab.

It is shown how standard ..delta..Vth and mobility measurements made on otherwise identical n- and p-channel transistors can be combined to accurately estimate radiation-induced ..delta..V/sub ot/ and ..delta..V/sub it/. Applications of the method are described. 12 refs., 2 figs.

Nuclear microprobe analysis (NMA) is a unique form of microbeam analysis in that it combines high lateral resolution with the high depth resolution techniques of conventional ion beam analysis (IBA) to nondestructively determine sample composition in three dimensions. By using depth sensitive IBA techniques (e.g., Rutherford Backscattering Spectrometry (RBS), Enhanced Backscattering Spectrometry (EBS) or Elastic Recoil Detection (ERD)), NMA finds its greatest utility in analyses requiring the following information: (1) 1--100 ppM sensitivity, (2) nondestructive three-dimensional depth profiling, and (3) quantitative light element analysis (e.g., the first two rows of the periodic table). This paper demonstrates the continuing evolution of NMA capabilities through two examples. First, the unique capabilities afforded NMA are shown in a simple yet accurate method to measure both oxygen and metal atom concentrations in Y-Ba-Cu-O alloys with micro-area ion beam analysis. Second, a NMA of buried tungsten lines in a silicon wafer demonstrates the complementary nature of information determined by NMA and scanning electron microscopy (SEM). 9 refs., 2 figs.

The ASSESS Neutralization Analysis module (Neutralization) is part of Analytic System and Software for Evaluation of Safeguards and Security, ASSESS, a vulnerability assessment tool. Neutralization models a fire fight engagement security inspectors (SIs) and adversaries. Results are based on probability of neutralization, P(N), which estimates the likelihood that SIs will win, given that SIs interrupt the attackers and begin an armed engagement. The calculating engine of the module is the Brief Adversary Threat Loss Estimator, BATLE. Engagements can have as many as thirty combatants on a side. Reinforcements may be introduced or combatant characteristics may be changed as many as ten times in one engagement. Inputs may be made with or without programmed guidance to the user. Combatant characteristics come from a modifiable library. Seven different characteristics can be independently specified for each combatant. Graphs of time distributions and studies of the sensitivity of P(N) to any combatant characteristic of either SIs or adversaries can be requested. Output files from Neutralization are used by Outsider Analysis to produce probability of security system win. 4 refs., 12 figs., 2 tabs.

The Facility Descriptor (Facility) module is part of the Analytic System and Software for Evaluating Safeguards and Security (ASSESS). Facility is the foundational software application in the ASSESS system for modelling a nuclear facility's safeguards and security system to determine the effectiveness against theft of special nuclear material. The Facility module provides the tools for an analyst to define a complete description of a facility's physical protection system which can then be used by other ASSESS software modules to determine vulnerability to a spectrum of insider and outsider threats. The analyst can enter a comprehensive description of the protection system layout including all secured areas, target locations, and detailed safeguards specifications. An extensive safeguard component catalog provides the reference data for calculating delay and detection performance. Multiple target locations within the same physical area may be specified, and the facility may be defined for two different operational states such as dayshift and nightshift. 6 refs., 5 figs.

Past experience in addressing the insider threat has led to the development of general principles for mitigating the insider threat while minimizing adverse impacts on site operations. Among the general principles developed was the requirement for real time tracking of personnel and material. A real time system for personnel and material tracking will aid in mitigating the insider threat by providing critical information regarding the movement and location of personnel and material. In addition, this system can provide an early detection mechanism for potential insider actions. This paper describes the development, operation, and performance of a technology-based system which utilizes radio frequency transmitters to achieve the real time tracking of personnel and material. The major elements of this system are a personnel tracking credential which cannot be removed from an authorized individual without an alarm being sounded, and a material control device which is utilized to control and monitor access to material. These elements form an insider protection system through the use of software which establishes the ''rules'' under which the system will operate. The performance of this system has been evaluated under both laboratory and operational settings in order to: (1) demonstrate the system's ability to successfully control access to material and areas by personnel, and (2) provide information regarding the status of materials in transit and storage. 3 refs., 1 fig.

Monte Carlo methods are used in a variety of applications such as risk assessment, probabilistic safety assessment, and reliability analysis. While Monte Carlo methods are simple to use, their application can be laborious. A new microcomputer software package has been developed that substantially reduces the effort requires to conduct Monte Carlo analyses. The Sensitivity and Uncertainty Analysis Shell (SUNS) is a software shell in the sense that a wide variety of application model can be incorporated into it. SUNS offers several useful features including a menu-driven environment, a flexible input editor, both Monte Carlo and Latin Hypercube sampling, the ability to perform both repeated trials and parametric studies in a single run, and both statistical and graphical output. SUNS also performs all required file management functions. 9 refs., 6 figs., 1 tab.

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.

Bipolaronic superconductivity requires two exceptional circumstances. First, at least some charge carriers must form bipolarons. Second, these bipolarons must be mobile (move coherently). However, beyond quasi-one-dimensional electronic systems, bipolarons have heretofore always been found to be ''small.'' Small (bi)polarons are very compact (bi)polarons that localize rather than move coherently. Thus, small bipolarons are not suitable carriers for bipolaronic superconductivity. However, in analogy with the case of large polarons, less compact bipolarons, ''large'' bipolarons, are expected to be mobile. These observations lead one to ask if and when large bipolarons can form in multi-dimensional electronic systems. Here the results of studies of the formation, motion and superconductivity of large bipolarons are summarized. 5 refs.

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.

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.

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 ..mu..m diameter range. Two test liquids were used: oleic acid and kerosene. 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 ..mu..m diameter, and had a measurement accuracy of about 2 ..mu..m for smaller droplets. The fiber-optic probe system exhibited similar behavior, although the 2 ..mu..m sizing uncertainty extended to droplets as large as 25 ..mu..m. The measurement uncertainties in the small diameter ranges are in qualitative agreement with the light-scattering computations of Al-Chalabi et al. (1988) and Saffman et al. (1984). 7 refs., 4 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.

Ion diode research on Sandia National Laboratories' Particle Beam Fusion Accelerator (PBFA) II has progressed significantly during the past two years as we have operated in the shot-a-day model with well-diagnosed proton and lithium ion diode loads. During this period, we have succeeded in demonstrating efficient proton beam generation and in focusing the beam to a full width at half maximum (FWHM) spot size of 5.2 mm. Power and energy densities equivalent to 5.4 (+0.9, /minus/0.8) TW/cm/sup 2/ and 73 kJ/cm/sup 2/, respectively, on a 6 mm diameter sphere from the full diode were obtained. Tests of ion diode operation with a simple Plasma Opening Switch (POS), opening at a current of 1-2 MA, indicate efficient energy coupling and a rapid turn on of iron when the POS opens. A model of diode operation has been developed which successfully describes the operating impedance of applied-B ion diodes on PBFA II, PBFA I, Proto II, and Proto I. In addition, we have developed the capability to perform particle simulations which have helped to determine optimized insulating magnetic field profiles and anode shapes for efficient ion beam generation and focusing. Lithium ion source experiments on PBFA II have succeeded in delivering 26 kJ of lithium ions to the axis using a field-enhanced LiF ion source. Several active lithium ion sources, which should allow improved lithium began generation and focusing, are now being prepared for testing on PBFA II. 11 refs., 10 figs., 2 tabs.

Personnel at Sandia National Laboratories, the Naval Research Laboratory, Cornell University, and Los Alamos National Laboratory are developing cost effective beams of lithium ions to bridge the energy gap between lasers and underground nuclear explosions in the national Inertial Fusion Program. We plan to probe the threshold for igniting thermonuclear fuel in the laboratory on the Particle Beam Fusion Accelerator II (PBFA II). We have met our April 1, 1989, milestone of 5 trillion watts per square centimeter power density on PBFA II. We wish to adapt the existing Hermes III accelerator at Sandia into a pre-prototype module of the DOE Laboratory Microfusion Facility for military applications in support of the DOE decision in the mid 90s on the best particle beam or laser for the facility. A German-American study concludes that our lithium ion approach offers the lowest cost option for fusion energy. 7 figs.

Superconducting polycrystalline thin films in the Tl-Ca-Bu-Cu-O system have been prepared by electron beam evaporation followed by appropriate sintering and annealing. Transition temperatures to 110 K and critical current densities to 600,000 A/cm/sup 2/ have been attained in oxygen annealed films. However, with only 16 minutes of air sintering and no oxygen anneal, oriented films have been obtained with T/sub c/'s to 107 K and J/sub c/'s to 450,000 A/cm/sup 2/. Single film devices utilizing a parallel array of weak links and a coplanar control line have been fabricated from the films. Oscillators as well as AM and FM modulators operating between 3 and 6 GHz have been demonstrated using this device concept. 24 refs., 4 figs.

A Personnel and Material Tracking System (PMTS) demonstrated at Argonne National Laboratories-West (ANL-W) in 1987 has resulted in the further development of this system. The results of the demonstration indicated immediate potential for the Material Monitoring/Tracking (MM) portion of the system. The MM system provides the separate functions of (1) observing all container movements, (2) authorized access approval,and (3) initiation and receipt of material transfers. All three functions are coordinated through a single computer which is known as the Computer Augmented Material Access (CAMA) computer. The Wireless Alarm Transmission of Container handling (WATCH) system provides Function 1, and the Mobile Accountability Verification Inventory Station (MAVIS) system provides Functions 2 and 3. Faster communications and the expanded and refined software package developed to provide Functions 2 and 3 stands out as the major accomplishment of this project. Increased functionality with enhanced protection against the insider threat in a more friendly operator interface is provided by this software. 3 refs., 2 figs.

In our instrumentation development efforts 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. Our goal has been to develop 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 procedure is delineated in reference to a Trial Waveform Digitizer Standard generated by the Waveform Measurements and Analysis committee appointed by the Instrumentation and Measurement Society of IEEE. The standard has been recently accepted by the IEEE and will become a published standard. In this work, special focus is given to the accurate measurement of effective-bit performance and differential nonlinearity of waveform digitizers. 3 refs., 8 figs.

This paper presents some simple concepts for fixtures that can be used in two and three-axis vibration testing. Two, two-axis fixtures were built and tested in the laboratory. Test results are shown, and serve to confirm the validity of the concept. Simple methods for extending the concepts for three-axis testing are discussed. 6 refs., 9 figs.

This paper presents a combined analytical and experimental method for establishing a set of equations to evaluate the equivalent forces acting on a structure. The method requires that a finite element model of the structure be established. It further requires that the accelerator responses to the external forces be measured at a number of points on the structure. The equivalent forces established in the analysis are a representation of the actual forces. The equivalent forces concentrate the effects of the external forces at the degrees of freedom where the acceleration responses are measured. 6 refs., 4 figs., 1 tab.

Second harmonic generation was measured for a thin corona-poled film of a dicyanovinyl azo dye incorporated in the side-chain methacrylate polymer. Measurements were performed at a wavelength of 1.58 ..mu..m as a function of incident angle for both p- and s-polarized incident light. From these measurements the form and magnitude of the second harmonic coefficient tensor were determined. The molecular distribution implied by the data is consistent with a thermodynamic potential containing only the dipolar orienting energy acting during poling. We have also demonstrated anomalous-dispersion phase-matched second harmonic generation for the first time using electric field induced second harmonic generation (EFISH) in a liquid solution of Foron Brilliant Blue S-R (FBB). Results are described. 10 refs., 4 figs., 2 tabs.

We report on the first ferroelectric measurements of chemically prepared KNbO/sub 3/ thin films. Polycrystalline KNbO/sub 3/ thin films were fabricated by dip coating substrates with methanolic solutions of potassium hydroxide and niobium ethoxide. Perovskite KNbO/sub 3/ was obtained for both bulk gels and films by using 800/degree/C firing treatments. For films, the intermediate temperature processing schedule was critical for the complete conversion of low temperature phases to perovskite KNbO/sub 3/. Raman spectroscopy and x-ray diffraction analysis confirmed that properly processed films possessed the orthorhombic distortion of the perovskite structure at room temperature. In response to a 1 kHz, sinusoidal field of 300 kV/cm amplitude, we measured the following ferroelectric properties: (1) a remanent polarization of 4.5 ..mu..C/cm/sup 2/, (2) a spontaneous polarization of 8.3 ..mu..C/cm/sup 2/, and (3) a coercive field of 55 kV/cm.

Sandia National Laboratories, in cooperation with industry and other national laboratories, has been benchmarking computer codes (''Structural Code Benchmarking for the Analysis of Impact Response of Nuclear Material Shipping Cask,'' R.E. Glass, Sandia National Laboratories, 1985; ''Sample Problem Manual for Benchmarking of Cask Analysis Codes,'' R.E. Glass, Sandia National Laboratories, 1988; ''Standard Thermal Problem Set for the Evaluation of Heat Transfer Codes Used in the Assessment of Transportation Packages, R.E. Glass, et al., Sandia National Laboratories, 1988) used to predict the structural, thermal, criticality, and shielding behavior of radioactive materials packages. The first step in the benchmarking of the codes was to develop standard problem sets and to compare the results from several codes and users. This step for structural analysis codes has been completed as described in ''Structural Code Benchmarking for the Analysis of Impact Response of Nuclear Material Shipping Casks,'' R.E. Glass, Sandia National Laboratories, 1985. The problem set is shown in Fig. 1. This problem set exercised the ability of the codes to predict the response to end (axisymmetric) and side (plane strain) impacts with both elastic and elastic/plastic materials. The results from these problems showed that there is good agreement in predicting elastic response. Significant differences occurred in predicting strains for the elastic/plastic models. An example of the variation in predicting plastic behavior is given, which shows the hoop strain as a function of time at the impacting end of Model B. These differences in predicting plastic strains demonstrated a need for benchmark data for a cask-like problem. 6 refs., 5 figs.

Obtaining robust phase estimates from phase differences is a problem common to several areas of importance to the optics and signal processing community. Specific areas of application include speckle imaging and interferometry, adaptive optics, compensated imaging, and coherent imaging such as synthetic-aperture radar. The purpose of this paper is to relate the equations describing the phase estimation problem to the general form of elliptic partial differential equations, and illustrate results of reconstructions on large M by N grids using existing, published, and readily available Fortran subroutines. 15 refs., 2 figs.

Vacuum arc remelting (VAR) is the principal secondary melting process used to produce ingots for almost all wrought Alloy 718 applications. We will attempt, with this paper, to summarize our previous work along with other unpublished work as it applies to VAR of Alloy 718. Successful application for a particular alloy/ingot diameter combination is believed to be dependent on achieving quasisteady thermal/solutal conditions at the solidification interfaces. Local thermal environment is strongly influenced by fluid flows which in turn are driven by global temperature gradients (convection) and magnetohydrodynamic (MHD) forces created by the arc's current distribution. Quasisteady conditions are enhanced when the metal vapor arc is stabilized in the diffuse mode where it provides optimal melting efficiency, macrouniform heating, and axisymmetrical fluid flows in the molten pool atop the ingot. Furnace conditions of low ambient gas pressures (<0.01 torr) and short electrode gaps (<10 mm) stabilize the diffuse mode. A transition from convective to magnetically dominant fluid flow occurs in the pool atop the ingot between 6.6 and 7.6 kA for production size ingots. Constricted arcs are stabilized at elevated ambient gas pressures and electrode gaps. Under these arc conditions fluid flows become unsymmetrical with respect to the ingot axis, ''shelf'' forms on portions of the ingot periphery, and melting efficiency is decreased. 19 refs., 13 figs.

Metalloporphyrins have appropriate properties for photosensitizing and catalysts solar energy storage reactions. Fundamental spectroscopic studies of metalloporphyrins and related enzymes that carry out C/sub 1/ chemistry can identify the factors controlling reactivity of the metal complexes. Research has concentrated on mimicking biological methanogenesis through investigation of the enzyme methylreductase, which carries out the final step in the reduction of Co/sub 2/ to methane. Transient and difference Raman spectroscopies were used to investigate the structural features of methylreductase, its nickel-hydrocorphin Cofactor F/sub 430/, and hydrocorphin and porphrin analogs of the active nickel complex. in particular, axial ligation at the nickel site was evaluated under a variety of conditions with the goal of elucidating the mechanism of methane synthesis. Studies of the tin-and antimony-porphyrin photoredox cycles were also carried out as possible solar-driven sources of reductant for biomimetic methane generation. 1 ref., 1 fig.

Packagings for transporting radioactive materials are required to survive exposure to environments. Package designers investigate design and analysis problems through structural and thermal testing of various components or models, using instrumentation to measure physical responses. The acquisition of high quality data from instrumentation is an essential part of the testing activity. To provide this quality of data, we are developing a mobile instrumentation data acquisition system dedicated for use in cask testing. This system is designed to acquire and analyze structural and thermal test data, and to provide leakage measurement capabilities. The mobile instrumentation system is housed in a 13.4m (44-ft) trailer transporter, which is self-contained with air conditioning, heating, and halon fire protection systems. External power from a commercial or motor generator source is line conditioned prior to distribution to the data acquisition equipment inside the trailer, and lightning protection is provided at the point where the measurement devices interface to the data acquisition equipment. This system is capable of performing data analyses and display of the acquired information within thirty minutes after an experiment.

Abstract not provided.

Beginning in April 1985, a working group on heat transfer met under the auspices of the Organization for Economic Cooperation and Development's Committee on Reactor Safety to define a standard problem set which could be used to benchmark codes used to predict cask thermal response. The problem definitions and solutions which resulted from these meetings as described in ''Standard Thermal Problem Set for the Evaluation of Heat Transfer Codes Used in the Assessment of Transportation Packages,'' R.E. Glass, et al., Sandia National Laboratories, 1988 are summarized in this paper. The problems that were defined address each of the major heat transfer mechanisms (conduction, convection, and radiation) that occur in a cask both during normal transport and as a result of the all- engulfing fire scenario. The problems were kept geometrically simple to minimize the resources required to obtain a solution while still addressing actual phenomena. This has resulted in a set of one- and two-dimensional problems. The solutions to this problem set include closed form analytical solutions, experimental data, and consensus of numerical solutions. For each problem the range of numerical solutions are presented. 1 ref., 4 figs., 2 tabs.

Wood is often used as the energy absorbing material in impact limiters, because it begins to crush at low strains, then maintains a near constant crush stress up to nearly 60 percent volume reduction, and there ''locks up.'' Hill has performed tests that show how wood is one of the best absorbers of energy per pound. However, wood's orthotropic behavior for large crush is difficult to model. In the past, analysts have used isotropic foam-like material models for modeling wood. A new finite element technique is presented in this paper that gives a better model of wood crush than the model currently in use. The orthotropic technique is based on locally isotropic, but globally orthotropic (LIGO) assumptions in which alternating layers of hard and soft crushable material are used. Each layer is isotropic; however, by alternating hard and soft thin layer, the resulting global behavior is orthotropic. In the remainder of this paper, the new technique for modeling orthotropic wood crush will be presented. The model is used to predict the crush behavior for different grain orientations of a 5 /times/ 5 inch sample of balsa wood. As an example problem, an impact limiter containing balsa wood as the crushable material is analyzed using both an isotropic model and the alternating layer model. 9 refs., 7 figs.

There has been considerable work over the past few years to study shock-induced solid state chemistry. In the present report, issues raised in the area are reviewed and critical concepts are discussed. The distinctive nature of solid state chemistry compared to liquid and gas phase chemistry is emphasized and material probes suitable for the study of solids are described. In order for solids to react in times less than one microsecond, unusual processes must be initiated in shock compression. Chief among the unique shock processes is the mixing of reactants by the large kinetic energy of shock-compression pulses. Mixing and fluid-like flow can lead to sufficiently intimate contact between reactants to permit complete chemical reaction in the solid state on the time scale of the experiment. Shock-induced solid state chemistry may be described as an unusually intense mechanochemical process. 24 refs., 2 figs.

Solar One is the world's largest central receiver power plant. During the last 4 years the plant availability was 80%, 83%, and 96%, respectively, during hours of sunshine. This reliability is considered to be excellent considering the plant is a first-of-a-kind facility and because it has been subjected to daily cyclic service. In this paper we present the frequencies and causes of the plant outages that occurred. The ten most important causes comprised 72% of the total outage time. Qualitative insights related to the cause and mitigation of these ten are provided. The information presented in this paper will be useful to studies aimed at improving the reliability of future solar central receiver power plants. It is also useful to members of the utility industry who are considering investing in this technology or are considering cyclic operation of conventional power plants. 4 refs., 3 figs.

Several issues have been identified as pertinent to sealing of radioactive waste repositories in bedded salt formations. These issues include: overall seal system functions and strategy for waste isolation; performance requirements for the seal system; need for redundancy; locations of long-term seals in excavations and boreholes; requirements for sealing interbeds and the disturbed rock zone (DRZ) seal stability for the required lifetime; and need for short-term seals in addition to long-term seals. These issues are defined in general terms, and some principles that may be useful in addressing them are presented. Although this presentation derives from experience with bedded salt, it has applicability to domal salt as well.

The following research is proposed: (1) Perform four to six new time-resolved lethality experiments on cadmium at projectile velocities 7 km/s, greater than that of our previous work at 5.2 km/s. The increased velocity will substantially increase the mass percentage of vaporization. Through simulation of these experiments, computer codes can be validated for hypervelocity impact when vaporization occurs. (2) Perform an additional four to six 1-D lethality experiments on zinc. This material undergoes substantial vaporization under the experimental conditions, and would expand our knowledge about the sensitivity of KEW lethality to shock-induced vaporization. (3) Perform two to four ballistic impact experiments with the ballistics gun at Sandia to provide a full validation of computational capabilities used in simulating the 1-D experiments. These experiments would probe phenomenology that is similar to the 1-D experiments, but with multi-dimensional debris propagation. This will extend the confidence in computer modeling to conditions analagous to KEW lethality applications.

A method which is capable of calculating the unsteady flow field around circular-arc bluff bodies of zero thickness is presented. This method utilizes linear vortex panels to model the body surface and a portion of the wake surfaces. Discrete vortices are used to model the remainder of the wake surfaces. Separation is assumed to occur at the sharp edges of the bodies. Numerical results for circular-arc bodies with included angles of less than 180/degree/ are compared with experimental data and found to be in good agreement. 31 refs., 15 figs.

A new recovery parachute system has been designed for the F111 crew escape module (CEM). The system includes a cluster of three 49-ft-dia ringslot-solid parachutes, a Kevlar deployment bag, and an explosively fired drogue gun to deploy the pilot parachute. Tests have been conducted that indicate the parachute system will meet the rate of descent requirement of 25 ft/sec at 5000 ft pressure altitude. To control the drag load developed by the parachutes, a new central reefing/disreefing system has been developed. Since the recovery parachute system is normally deployed crosswind from the CEM, line sail of the suspension lines during early tests was a problem but has been minimized by a dual pilot parachute system. 6 refs., 7 figs.

The possibility of capturing cosmic dust at hypervelocity has been demonstrated in the laboratory and in the unintended Solar Max spacecraft. This technology will enable a comet coma sample return mission and be important for the earth orbital cosmic dust collection mission, i.e., the Space Station Cosmic Dust Collection Facility. Since the only controllable factor in an intact capture of cosmic dust is the capturing medium, characterizing the effectiveness and properties of available capture media would be very important in the development of the technique for capturing hypervelocity cosmic dust intact. We have evaluated various capture underdense media for the relative effectiveness for intact capture. 2 refs., 2 figs.

A vibration test method has been proposed where control is accomplished using extremal control of the force and acceleration at the input to a test item. This proposal is examined with several examples. The method does limit the acceleration input at frequencies where the test item responses tend to be unrealistically large. However, the method's application is not straightforward and care must be taken in the application of the method. 9 refs., 16 figs.

The microstructure, mechanical properties and fracture characteristics of a pulsed Nd:YAG laser weld in a rapid solidification/powder metallurgy (RS/PM) Al-8 wt % Fe-2.3 wt % Mo alloy have been investigated. Results showed the high power density but low total energy input associated with pulsed Nd:YAG laser welding to promote extremely rapid fusion zone (FZ) cooling rates in the vicinity of 10/sup 5//degree/C/s. The weld FZ microstructure consisted primarily of submicron-sized spherical dispersoids in a matrix of fine dendritic-alpha aluminum. A dispersoid-coarsened heat-affected zone (HAZ) was also observed in the boundary between successive, overlapping melt zones. Transverse-weld tensile testing found fracture to occur in the unaffected base metal indicating 100% weld joint efficiency. Longitudinal-weld bend ductility testing revealed fracture initiation and propagation to be associated with the HAZ between successive melt zones at a bend ductility level only marginally below that of the base metal. 12 refs., 7 figs.

A good many words have been spoken and written (some by the present authors) about factoring very large numbers. Therefore, the thrust of this paper is a discussion of how the quadratic sieve algorithm has been adapted to work on a 1024-processor hypercube at Sandia National Laboratories. A brief description of the hypercube, an NCUBE/ten, its idiosyncrasies and its power, as well as some comparisons of timings between numbers factored on the CRAY and on the hypercube, are included. 6 refs., 1 tab.

PBFA II is the first pulsed power accelerator designed and built specifically to produce light ions for driving targets in Sandia National Laboratories inertial confinement fusion program. Recent progress in ion beam generation and focusing has been excellent. Record ion beam intensities have been obtained. Development of an extensive array of diagnostics and advances in the theory of ion diodes have had a major impact on this progress. A summary of recent progress and the present status of the PBFA-II light ion beam fusion program is given. 40 refs., 4 figs.

Amorphous metal foil-wound inductors have been tested as ferromagnetic saturable inductive elements for pulsed-power (multi-terawatt) switching modules in the inertial confinement fusion program at Sandia National Laboratories. In simulated capacitor testing premature dielectric breakdown of thin polyethylene terephthalate film insulation in the inductor windings occurs at considerably below 2500 V. This appears to be due to inadvertant dielectric damage from micro-spikes on the amorphous foil surface. Electron micrographs and dielectric breakdown data illustrate that electrophoretically-applied dielectric coatings, deposited from organic aqueous colloid dispersions, can be used to provide insulating coatings on the foil which provide a 240% improvement (6000 V) in the breakdown strength of wound amorphous foil inductors. The theory and operation of a dedicated electrophoretic continuous coating system is described. The machine was constructed and successfully applied for dielectric coating of amorphous metal foil. Additional possible applications exist for practical dielectric coating of metallic films or foils used in various commercial wound-type capacitor structures. 7 refs., 9 figs.

The influence of coal structure on primary conversions and oil yields in thermolytic extraction with different H-donor and non-H-donor solvents and in dry catalytic hydrogenation has been investigated. Pre-soaking of coal/H-donor solvent slurries at 250/degree/C increased conversions and the level of hydrogen transfer at short contact times (SCT, less than or equal to 10 min), demonstrating studies, prior removal of THF-extractable material (mobile phase) from one bituminous coal actually gave rise to higher conversions to pyridine-solubles for non-donor polynuclear aromatic compounds (PAC), such as naphthalene, phenanthrene and pyrene. These findings highlight the difficulties in relating primary conversions to coal characteristics. In contrast, oil yields have been found to increase broadly with decreasing rank in both H-donor solvent extraction with a process solvent and dry catalytic hydrogenation. However, in SCT tetralin extraction where poor physical contact between coal and solvent exists, neither total conversion nor oil yield correlates with rank. 23 refs., 1 fig., 3 tabs.

We first discuss the progress in linear optics, in particular, the formulation and application of geometrical-optics approximation and its generalization. We then discuss the progress in non-linear optics, in particular, the enhancement of a first-order Freedericksz transition and intrinsic optical bistability in homeotropic and parallel oriented nematic liquid crystal cells. Finally, we discuss the liquid crystal alignment and surface effects on field-induced Freedericksz transition. 50 refs.

The dramatic improvement in silicon concentrator cell efficiency recently demonstrated in university laboratories has had a significant influence on concentrator technology development. This paper briefly describes concentrator field experience, economics, current technology paths, and concludes with a detailed summary of concentrator cell performance. 29 refs., 2 figs., 3 tabs.

When a technology such as solar energy enters the everyday world, the documentation about it must also become part of the technology transfer. The challenge in creating publications about technical subjects for semi-technical people or for popular use is to be both accurate and interesting. The process of creating this documentation should begin by carefully defining the audience and aiming the publication at it. To a large extent, the audience determines both the content and the language that will be used. 2 refs.

In this work, compaction-induced combustion in packed beds of nitrocellulose-based ball propellants is modeled using a multiphase mixture description. This model is applied to conditions simulating low-velocity impact experiments of Sandusky, et. al. (NSWC). A two- stage combustion model is used whereby compressive reaction begins at the compaction front. Subsequent energy release is delayed following an induction rate law based on time-to-reaction experimental data. Given conditions of sufficient energy release and heat transfer, grain burning is initiated when granular surface temperatures exceed decomposition conditions. Numerical solutions of the one-dimensional multiphase conservation equations are obtained using an adaptive finite element method and calculations are compared to experiments investigating various impact loading conditions on the ball propellants TS3659 and WC140. 11 refs., 12 figs., 1 tab.