Publications

Nuclear deterrence, a cornerstone of US national security policy, has helped prevent global conflict for over 40 years. The DOE and DoD share responsibility for this vital part of national security. The US will continue to rely on nuclear deterrence for the foreseeable future. In the late 1950s, Sandia developed satellite-borne nuclear burst detection systems to support the treaty banning atmospheric nuclear tests. This activity has continued to expand and diversify. When the Non-Proliferation Treaty was ratified in 1970, we began to develop technologies to protect nuclear materials from falling into unauthorized hands. This program grew and now includes systems for monitoring the movement and storage of nuclear materials, detecting tampering, and transmiting sensitive data securely. In the late 1970s, negotiations to further limit underground nuclear testing were being actively pursued. In less than 18 months, we fielded the National Seismic Station, an unattended observatory for in-country monitoring of nuclear tests. In the mid-l980s, arms-control interest shifted to facility monitoring and on-site inspection. Our Technical On-site Inspection Facility is the national test bed for perimeter and portal monitoring technology and the prototype for the inspection portal that was recently installed in the USSR under the Intermediate-Range Nuclear Forces accord. The articles in the special issue of Sundiu Technology describe some of our current contributions to verification technology. This work supports the US policy to seek realistic arms control agreements while maintaining our national security.

The Department of Energy sponsored a workshop on the use of burnup credit in the criticality design of spent fuel shipping casks on February 21 and 22, 1988. Twenty-five different presentations on many related topics were conducted, including the effects of burnup credit on the design and operation of spent fuel storage pools, casks and modules, and shipping casks; analysis and physics issues related to burnup credit; regulatory issues and criticality safety; economic incentives and risks associated with burnup credit; and methods for verifying spent fuel characteristics. An abbreviated version of the DOE workshop was repeated as a special session at the November 1988 American Nuclear Society Meeting in Washington, DC. Each of the invited speakers prepared detailed papers on his or her respective topic. The individual papers have been cataloged separately.

The goals of our Basic Energy Sciences (BES) Materials Science Program at Sandia are: (1) Perform basic, forefront interdisciplinary research using the capabilities of several organizations. (2) Choose programs broadly complementary to Sandia's weapons laboratory mission, but separably identifiable. (3) Perform research in a setting which enhances technological impact because of Sandia's spectrum of basic research, applied research and development engineering. (4) Use large, capital-intensive research facilities not usually found at universities. The BES Materials Science program at Sandia Albuquerque has the central theme of Scientifically Tailored Materials. The major objective of this program is to combine Sandia's expertise and capabilities in the areas of solid state sciences, advanced atomic-level diagnostics, and materials-processing science to produce new classes of tailorable materials for the US energy industry, the electronics industry and for defense needs. Current research in this program includes ion-implantation-modified materials, physics and chemistry of ceramics, tailored surfaces for materials applications, strained-layer semiconductors, chemical vapor deposition, surface photo kinetics, organic and high-temperature superconductors, advanced growth techniques for improved semiconductor structures and boron-rich very high temperature semiconductors.

The Annual Solar Thermal Technology Research and Development Conference is being held at the Holiday Inn Crowne Plaza in Arlington, Virgina, Marh 8 and 9, 1989. This year the conference is meeting in conjunction with SOLTECH '89. SOLTECH '89 is a jointly sponsored meeting of the Solar Energy Industries Association, Interstate Solar Coordination Council, Sandia National Laboratories and the Solar Energy Research Institute. This report contains the agenda, extended abstracts and most significant visual aids used by the speakers during the Solar Thermal Technology research and development sessions. The program is divided into three sessions: Solar Electric Technology, Non-Electric Research and Development and Applications, and Concentrators.

As part of the Strategic Petroleum Reserve (SPR), the Weeks Island oil storage site is a converted salt mine that contains approximately 73 million barrels of oil overlying 0.5 million barrels of brine. The oil is contained on two levels of the converted mine which are connected by a number of shafts and openings. Oil recycle exercises are periodically conducted to test the oil fill and withdrawal systems in which oil is simultaneously injected and withdrawn from two different locations in the lower level, and brine may be transported around the lower level of the mine by the movement of the oil. 11 refs., 16 figs.

An expert system developed to provide assistance to those involved with the creation, modification, interpretation and maintenance of Sandia's Engineering Procedures is described. 6 refs., 2 figs.

The Engineering Graphics System (EGS) is a computer program for use on Digital Equipment Corporation VAXstation color workstations. Its purpose is to manage and plot sets of engineering analysis data for use in reports and presentations. It is capable of producing nearly any type of x-y plot from a set of tabulated data. After the plot curves have been retrieved from the tabulated data, EGS can be used to interactively modify the appearance of the plot for use in a report or presentation. Modifications appear on the workstation display exactly as they appear on final hardcopy, which avoids costly iterations. Hardcopy plots can be made on two different black and white laser printers and on two different color printers, and plots can be converted for use by the Interleaf technical publishing software. 222 figs.

Power deposition measurements have been carried out on the ALT-II toroidal belt pump limiter and the inner bumper limiter in TEXTOR for Ohmic, neutral beam and RF heated discharges. Two infrared cameras and the ALT-II thermocouple array indicate that {lambda}{sub E} remains unchanged (7 mm) in the presence of beams but increases to 10 mm with ICRH. The heating distribution is less uniform on the bumper limiter than on ALT-II, which potentially could explain the differences seen in graphite surface pumping. 9 refs., 3 figs., 1 tab.

The microstructure and mechanical properties of high purity aluminum implanted with 20 at. % oxygen to a depth of roughly 500 nm and subjected to various thermal histories have been examined. Transmission electron microscopy and Rutherford-backscattering spectrometry were used to characterize the depth and nature of the implanted zone. As implanted, the material appears to contain a homogeneous distribution of disordered precipitates with sizes of 1.5-3.5 nm. Annealing at 450 or 550{degree}C/1 hr induces ordering of the precipitates but only causes slight coarsening. Ultra-low load identation hardness testing was used to probe the mechanical response of the surface-modified material. The data from the hardness tests were interpreted through the use of a finite-element model; the results indicate the flow stresses of an implanted and annealed layer are as high as 1600 MPa. The as-implanted material is much harder, approaching 3300 MPa. The degree of strengthening expected for the as-implanted and post-annealed material on the basis of the observed microstructure was estimated using several micromechanical models, and the results conform to the findings from indentation testing. 9 refs., 5 figs.

It has been observed on TEXTOR that in low density discharges the electrons gain enough energy to emit relativistic synchrotron radiation in the 3--6 {mu}m IR-range, and this radiation is due to electrons with energies up to 30 MeV. The momentum in perpendicular direction amounts to about 1/10 of the longitudinal one. The total number of runaways is of the order of 10{sup 16} electrons, and they carry a current of about 20% of the total plasma current. 3 refs., 1 fig.

We consider problems related to the computation of Hermite and Smith normal forms of integer matrices, and more generally matrices over a principal ideal ring. First, we show that if the matrix A is m {times} n, with rank m and integer entries bounded in absolute value by T, then the Hermite normal form can be computed in O(m{sup 2}nB(m log(mT))) bit operations, where B(t) denotes a function that bounds the time required to perform the extended Euclidean algorithm on two t bit integers. Furthermore we show that the Smith normal form can be computed in O(m{sup 3}nB(m log(mT))log(mT)) bit operations. In the second part of the paper we apply fast matrix multiplication techniques to the problem of triangularizing a matrix over a ring using elementary column operations. We also prove that matrix inversion and multiplication are equivalent in complexity over an arbitrary Principal Ideal Domain, generalizing a result of Bunch and Hopcroft. We then apply our general results to obtain an algorithm for triangularizing integer matrices that has a faster running timer than the known Hermite normal form algorithms. The triangular matrix that is computed has small entries like the Hermite normal form, and will suffice for many applications. In the last part of the paper, we discuss a probabilistic method for calculating Smith normal forms. 17 refs.

We have examined several crystals belonging to the Tl-2122 structure type (Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8} with c = 29{angstrom}), and have shown that cation solid solution occurs. Such cation disorder appears to be responsible for the observed small differences in lattice parameters reported by various investigators and to contribute towards the substantial variation in the superconducting transition temperatures. 10 refs., 2 tabs.

Nuclear power plants present the fire protection community with unique challenges. In addition to the traditional concerns of life safety and property loss prevention, nuclear safety analysts must also be concerned with the impact of fires on the safe operability of the nuclear reactor. Safe shutdown equipment must be protected from fire damage. When nuclear power plants were first designed and built, fire safety considerations were based primarily on the same criteria applied to general industrial facilities, primarily those concerning life safety and property loss prevention. This practice continued until 1975 when the Brown's Ferry nuclear reactor site experienced a severe cable tray fire. The fire burned for over seven hours, due in part to the reluctance of on-site personnel to use water on the fire for fear of shorting out critical electrical circuits. 4 figs.

The radiation spectrum constituents of interest to microelectronics are prompt gamma or x-ray, total dose, neutrons (or protons), and cosmic radiation. Each of these constituents has a unique effect upon microelectronic components and requires unique techniques to improve the microelectronic radiation tolerance to such an exposure. This paper reviews the radiation effects associated with the natural space and nuclear reactor radiation environment, that is to say, total dose, neutrons, and cosmic rays. 2 refs., 6 figs.

Shock-induced reaction synthesis (SRS) is used for solid state processing of Ni-Al, Ni-Si, and Nb-Si type compounds, starting with elemental powder mixtures. The constituent elemental powders are blended in different stoichiometries and packed at 65% density in stainless steel capsules. A steel flyer plate, accelerated by the detonation of an explosive, impacts the powder containing capsules embedded in a steel recovery fixture backed by a momentum trap. The shock wave generated upon impact triggers a self-sustaining, exothermic reaction between the elemental powder constituents, thereby synthesizing the compound and at the same time consolidating the porous mass into 12mm diameter by 5mm thick compacts. The characteristics of the SRS technique and the structural features of the shock synthesized products will be discussed. 18 refs., 11 figs.

Preliminary BUCKSHOT simulations of a recirculating linear accelerator have been made. Two accelerator configurations have been examined for a variety of beam currents (10-40 kA). The first configuration is an attempt to simulate conditions accessible to near-term experiments. The second configuration tries to mock up a next generation application type machine. 3 figs.

Hypervelocity launchers are used to study the high-pressure equation of state of materials in regimes inaccessible by other methods. Two-stage light gas guns have been extremely useful for these applications, but have a practical velocity limit of about 8--9 km/s for impact studies. In this paper, we describe a three-stage launcher consisting of a two-stage light gas gun combined with a third-stage railgun, which overcomes previous velocity limitations pertaining to two-stage guns. This launcher is being developed for operation to 15 km/s and has achieved projectile velocities of 7.2 km/s to date. 10 refs., 9 figs., 1 tab.

The in-plane linear elastic constants of woven fabric are determined in terms of the specific fabric microstructure. The fabric is assumed to be a spatially periodic interlaced network of orthogonal yarns and the individual yarns are modeled as extensible elastica. These results indicate that a significant coupling of bending and stretching effects occurs during deformation. Results of this theoretical analysis compare favorable with measured in-plane elastic constants for Vincel yarn fabrics. 17 refs., 2 figs., 1 tab.

The winding process is encountered frequently in manufacturing, such as winding of polymer films and paper, laminated pressure vessel construction, and the manufacture of wound capacitors. The winding of capacitors will typically involve hundreds of plies of conductor and dielectric wound over a core. Due to the large number of layers, the calculation of the mechanical studies within a wound capacitor is a significant computational task. The focus of Part II of this paper is the formulation and application of optimization techniques for the design of wound capacitors. The design criteria to be achieved is a specified uniform wound tension in a capacitor. The paper will formulate an optimization statement of the wound capacitor design problem, develop a technique for reducing the numerical calculation required to repeatedly analyze the capacitor as required by the optimization algorithm, and apply the technique to an example. 4 refs., 13 figs., 4 tabs.

Horizontal stress directions (azimuths) determined from anelastic strain recovery (ASR) and differential strain curve analyses (DSCA) were compared with those from wellbore breakouts detected by borehole televiewer and oriented caliper logs. The ASR/DSCA techniques appear to be more sensitive then the log techniques and provided stress azimuth predictions at depth intervals where the log data did not. Stress azimuth determinations were also made from other core analyses techniques, which, like ASR/DSCA, are associated with the formation of stress release microcracks. Preliminary insights were obtained in the applicability of these other techniques. This work provides information on the stresses at two well sites 3.6 miles apart in Western Colorado; and showing the comparative data in this context provides information on how to apply these techniques and provides an understanding of the apparent influence of geologic effects (topography, depositional environment) on the stresses. 28 refs., 10 figs., 3 tabs.

This paper discusses a new telerobotic control concept which couples human supervisory commands with computer reasoning. The control system is responsive and accomplishes an operator's commands while providing obstacle avoidance and stable controlled interactions with the environment in the presence of communication time delays. This provides a system which not only assists the operator in accomplishing tasks but modifies inappropriate operator commands which can result in safety hazards and/or equipment damage. Research and development of this concept is being carried out in the Telerobotics Research Laboratory at Sandia National Laboratories. 12 refs., 4 figs.

Over the past decade, Sandia National Laboratories has managed the Department of Energy (DOE)-sponsored programs for the development of the sodium/sulfur battery technology. Two DOE offices have provided support for these programs: the Office of Energy Storage and Distribution (OESD) and the Office of Transportation Systems (OTS). The ultimate goal of these ongoing efforts is to develop and demonstrate high performance, cost-effective systems suitable for both stationary and mobile applications. A part of Sandia's responsibility is to evaluate the status of the technologies and to address specific problems that are encountered during the development process. The number and level of effort devoted to these tasks are scaled such that the funding emphasis is given to the contracted engineering development programs. Two of the major safety-related concerns with sodium/sulfur EV batteries are the potential consequences associated with large temperature increases and vehicle accidents. The first three tasks represent Sandia's initial effort to help identify effective methods to limit the temperature rise in the battery during both expected and unexpected conditions and to assess one possible result of a vehicle accident. Descriptions of each task along with selected results are given in the following sections. 4 figs., 2 tabs.

Inorganic thin films with molecular sieving properties have been formed by embedding microcrystals of zeolite Y and chabazite in a glassy silica matrix. The silica matrix was derived from sols prepared from tetraethylorthosilicate hydrolyzed under either acidic or basic conditions in alcoholic solution. Dip-coating, deposition of suspensions, or coating of zeolite dispersions with the glassy silica matrix were used to create the zeolite-silica films. The access of different probe molecules into the zeolitic part of the thin film was examined with in situ FTIR techniques and temperature-programmed-desorption studies. With all combinations of deposition techniques and silica matrices, the resulting films showed the molecular sieving properties of the parent zeolite. © 1989, Elsevier Science & Technology. All rights reserved.

Stand-off hypervelocity particle shields offer potential weight savings of an order of magnitude or more over conventional homogeneous armors. Based on an earlier complete model for the design and optimization of a stand-of shield system, a more restricted model appropriate for retrofit shields is described. Procedures to minimize the shield mass are provided, and scaling laws for many of the important parameter relationships are illustrated. 6 refs., 5 figs.

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.

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

This report describes a capacity planning project for Engineering Information Management (EIM) systems at Sandia National Laboratories. The purpose was to develop a method for predicting the ability of current hardware computer systems to meet future demands and to address the magnitude of required upgrades. Specific activities included the generation and analysis of alternatives, the selection of analytic modeling as the appropriate vehicle, construction and validation of the model, and the development of recommendations.

Thin silicon nitride (Si/sub 3/N/sub 4/) films are widely used as a dielectric in metal-nitride-oxide-silicon (MNOS) structures for radiation hard non-volatile memories. The retention of charge in these devices depends, among other things, on the chemistry of the films. It has been reported that charge transport in MNOS structures can be reduced by replacing the Si/sub 3/N/sub 4/ film by a silicon oxynitride (SiO/sub x/N/sub y/) film. In order to understand the relationship between chemistry and retention of charge, it is necessary to have a technique that can determine the chemistry of the films as a function of depth. This can be accomplished with Auger electron spectroscopy by using fingerprint spectra for each of the elements and compounds present in the sample. By using classical least-squares techniques, a unique combination of the standard spectra can be found that best fits the unknown spectrum. When this method is repeated for each spectrum in a depth profile, a chemical state depth profile is obtained. The use of this technique to profile oxynitride films where the SiO/sub 2/ content varies between 0 and 12 atomic percent is presented. 6 refs., 7 figs.

Time stepping algorithms are often used to solve parabolic and hyperbolic differential equations numerically. These algorithms are generally regarded as sequential in time; that is, the solution on a time level must be known before the computation of the solution at subsequent time levels can start. While this remains true in principle, we demonstrate that it is possible for processors to perform useful work on many time levels simultaneously. Specifically, it is possible for a processor assigned to a ''later'' time level to compute a very good initial guess for the solution based on approximations to the solutions on ''previous'' time levels, thus reducing the time required for solution. The reduction in the solution time can be measured as parallel speedup. We demonstrate two parallel time stepping algorithms that can be used for both linear and nonlinear problems. We compare the two algorithms and discuss their performance in terms of parameters associated with classical time stepping algorithms. 4 refs., 5 tabs.

A general representation approach is described which employs a hierarchy of holes and notches. A matching procedure is also described which allows non-ideal image hierarchies to be matched to class representations. The representation and matching methods are demonstrated on a set of handgun photographs. Examples of handguns which are different in detail are shown to exhibit the same class characteristics, while other similarly shaped objects are correctly distinguished from the handgun class. 6 refs., 8 figs.

We are currently investigating a solar-driven photocatalytic process that promises to destroy low concentrations of hazardous organic molecules in large volumes of contaminated groundwater or industrial waste streams. Preliminary results of laboratory-scale screening tests using a model compound, salicylic acid, and titanium dioxide catalyst have shown that no measurable reaction occurs without both uv light and catalyst; no measurable volatilization of the salicylic acid occurs at room temperature; salicylic acid destruction rates depend on catalyst supplier and concentration and on uv light intensity; and some intermediates are being formed and subsequently destroyed. Observed reaction rates are consistent with those observed in an initial pilot-scale solar test of a falling-film reactor, although further testing will be required to quantify the comparison. 10 refs., 5 figs.

A novel technique is presented for segmenting seismic waveforms. The method produces waveform segments which closely correspond to explosion and earthquake signal onsets as well as additional structure of interest. Noise spikes or glitches are also successfully isolated. The approach uses threshold parameters obtained from human segmentation judgment tests and requires only simple, time domain calculations. 6 refs., 3 figs.

Sandia National Laboratories (SNL) performs software security analyses of many systems having strong security requirements. This paper gives an overview of a software security analysis methodology that has evolved at SNL. This methodology is based on experience gained in the analysis of critical software-controlled systems. The paper describes analysis activities and how they relate to the traditional software life cycle. Topics discussed include: planning for the analysis; supporting the development and documentation of security requirements; identifying and analyzing the threat; acquiring and utilizing software design and implementation materials; identifying positive design features; scaling the analysis effort to the threat; analyzing the high-level design; analyzing the source-code and target implementations; reporting results; interacting with system and component development groups; and supporting the authentication of the software product before it is fielded. The paper also stresses the importance of independence of analysis and development groups.

In the early 1980s, the US Department of Energy/Defense Programs (DOE/DP) initiated a project to develop a safe and efficient transportation system for defense high-level waste (DHLW). Sandia National Laboratories (SNL) provides a technical oversight and test support and General Atomics provides the design and safety analysis of the shipping system. The specific activities include designing, testing, certifying and fabricating a legal-weight truck cask system for DHLW canisters that are expected to be first produced by the Defense Waste Processing Facility (DWPF) at the Savannah River Plant (SRP) in South Carolina and later produced by facilities in Washington and Idaho. A truck cask was selected in order to provide a flexible capability for transporting vitrified waste to support a variety of expected experimental program needs. The first planned shipping campaign was to transport a limited number of DHLW canisters from South Carolina to the Waste Isolation Pilot Plant (WIPP) in New Mexico. However, changes in experimental program plans the passage of the Nuclear Waste Policy Act in late 1982, and the subsequent decision to have DHLW permanently placed in the eventual civilian repository resulted in revisions to the mission of the cask development program funded by DOE/DP. 15 refs.

We have sputter-deposited aluminum oxide coatings using a dual ion beam system with a mixture of argon plus 10% oxygen as the working gas. Ambient substrate temperatures and substrate temperatures of 360{degree}C were maintained. The coatings were deposited at deposition rates between 7 and 10 nm/min, with and without concurrent ion bombardment from the second ion gun. Substantial variations in the microstructure and the amount of entrained gas in the coatings were observed. The coatings contain a mixture of varying amounts of {gamma}-Al{sub 2}O{sub 3} and amorphous aluminum oxide. Relatively large, 0.5 {mu}m islands of {gamma}-Al{sub 2}O{sub 3} crystallites surrounded by an amorphous matrix were observed in coatings deposited onto heated substrates with ion bombardment from the second ion gun during deposition. Coatings bombarded with a second ion beam during deposition contain more argon as determined by energy dispersive x-ray analysis. The Raman spectra exhibited by the coatings suggest a variation in chemical reactivity and/or porosity which depends on the deposition conditions. 18 refs., 6 figs.

The operation of TORE SUPRA at full power (25MW, 30s) has led to the design of a full set of actively pumped carbon limiters to remove at least 8MW and to partially control the particle balance. An interim version is now installed, composed of 5 vertical and one horizontal outboard (OPL) pump limiters, semi-inertially water cooled. The latter is a result of a collaboration between the US DOE and the Association EUR-CEA, it is fully instrumented and therefore can serve as a reference for the final design. Ohmic discharges (1.85T, 740kA, 8.5s) in helium have been used to test the thermal load on and the particle exhaust efficiency of the OPL. In these experiments the plasma is formed on the inner wall (R = 232 cm, a = 76 cm) and subsequently displaced (6 cm) outward, early on the current plateau, to lean on the OPL (R = 238 cm, a = 75 cm). In addition to the limiters above, a non-pumped outboard (ONLP) limiter of identical shape to the OPL served to produce similar discharges for better comparison and determination of particle control. A comparison is made hereafter of the thermal load and particle pumping effects on the OPL when the plasma is in contact either with the OPL/ONPL alone or with the OPL and the vertical limiters together. 3 refs., 1 fig., 2 tabs.

Particle collection, removal, and exhaust by the toroidal belt pump limiter ALT-III have been measured in deuterium discharges with co-, counter-, and balanced injection of 48 keV neutral hydrogen particles. Particle collection increases from 50-80 A to 150-320 A during 1.2 MW of co- or counter-injection or 2.4 MW of balanced injection. The removal rate for pumping at two of the eight blades (3 of 15 scoops) reaches 2.7 Torr-l/s with a removal efficiency of nearly 45%. Extrapolating these results to a full belt with 15 scoops and eight pumps yields 140 amps of removal. This compares favorably with the maximum injectable current of 50 A and suggests that ALT-II with full pumping can provide sufficient exhaust during NI heating. 4 figs.

The surface properties of symmetric microphase separated diblock copolymers of polystyrene (PS) and polymethylmethacrylate (PMMA) were investigated using X-ray photoelectron spectroscopy (XPS), the specular reflectivity of neutrons and secondary ion mass spectrometry (SIMS). PS, the lower surface energy component, exhibited a preferential affinity for the free surface. For copolymers that are far from the bulk microphase separation transition (MST), the surface consists of a layer of pure PS. When the system is close to the MST the surface is a mixture of PS and PMMA. The PS surface excess can be described by a N-{sup 1/2} dependence, where N is the number if segments that comprise the copolymer chain. It is shown that the surface undergoes an ordering transition at a temperature T{sub s} that is above that of the bulk MST. The ordering of the bulk lamellar morphology is induced by an ordering at the surface. This is analogous to the ferromagnetic order observed in systems such as Gd at temperatures above the bulk Curie temperature. The results here are discussed in light of previous work on copolymer surfaces and in light of mean field theory. 31 refs., 8 figs.

Oxygen ion beam bombardment has been studied as a means for incorporating oxygen into thin films of Y-Ba-Cu-oxide either by enhancing the transport of oxygen to substrates during ion-beam sputtering, or by direct incorporation of oxygen by ion-assisted deposition. Optical emission spectroscopy was used to study the ion-beam bombardment of bulk superconducting targets as the oxygen content of the ion beam was varied between 0% (pure argon) and 100% oxygen. This showed that oxygen did not directly combine with metallic elements in the target to increase the oxygen content of the stream of particles moving toward the substrate. The oxygen content of the sputter beam did, however, change the relative emission intensity from the various target components. Addition of a second ion beam directing an oxygen beam toward the substrate as the film is grown, caused large variations in the stoichiometry of the deposited films. At low ion currents, no increase in the oxygen content of the films was detected, while at relatively high currents, the oxygen incorporation increased. However, the sputtering of the metallic components of the film increased, leading to very low growth rates. 8 refs., 5 figs.

Intense beams of light ions are being developed at Sandia National Laboratories as a promising driver option for Inertial Confinement Fusion (ICF) implosions. The Particle Beam Fusion Accelerator II (PBFA II) will provide the physics basis for light-ion-beam driven ICF targets. Recent progress made in ion beam generation focusing on PBFA II has led to a record 5.4 TW/cm{sup 2} peak focal intensity with {gt}80 kJ proton energy delivered to a 6-mm diameter sphere. The driver-development program on PBFA II is reviewed. A design concept for a light ion beam driver for the Laboratory Microfusion Facility is also presented. 34 refs., 9 figs., 1 tab.

In an earlier paper, we reported that it is possible to train a first-order multi-layer feedforward network with backpropagation to classify raw 8-bit images of vehicles. We concluded that a linear feedforward network is capable of within-class generalization when trained with perspective views taken every 10{degree}, but it is incapable of one-class generalization. This paper describes the results of a set of experiments to train a feedforward network with second-order inputs to perform one-class classification on image data. We compare the results of the first-order network and the second-order network and show that the second order network is better able to generalize as a one-class classifier. 7 refs., 6 figs.

Short communication.

Ion beam studies on radiation enhanced sublimation (RES) have shown that above 800{degree} C energetic ions incident on graphite produce erosion in the form of carbon atoms with thermal energies and that the erosion rate rises roughly exponentially with temperature. Until recently, the question remained whether RES would scale linearly with flux over three to four orders of magnitude to the plasma edge fluxes in CIT and ITER, where the predicted erosion rates would severely limit the designs for plasma-facing components. Also, RES and carbon self-sputtering may also be involved in the carbon blooms'' observed in TFTR and JET. The data reported here from PISCES, a plasma source at UCLA, are the first RES data at fluxes approaching the plasma edge conditions in a large tokamak and they show little reduction from a direct linear dependence upon flux. Erosion rates measured by weight loss are reported for POCO graphite exposed to helium plasmas for a temperature range from 900--2000{degree} C, ion energies of 30--300 eV, ion fluxes of 1--6 {times} 10{sup 18} cm{sup {minus}2} s{sup {minus}1}, densities of 2--10 {times} 10{sup 12} cm{sup {minus}3} and electron temperatures of 4-10 eV. For these conditions, the amount of redeposition and carbon self-sputtering was minimal. Over 1700{degree} C, there is evidence of electron emission from the sample. 26 refs., 4 figs., 1 tabs.