A short history of the TEAM workshops is presented, with emphasis on the first two rounds of workshops and the recent workshops in Berlin and Okayama. New problems provide benchmarks for new applications and interest, but old problems continue to provide benchmarks for new methods and approaches. There is a trend to attempt to solve more and more complicated problems on a personal computer (PC). Problem 8 (a slot in a conducting plate) has been solved on a PC using the eddy- current code ELEKTRA.

We demonstrate large giant magnetoresistance (GMR) values of Co/Cu multilayers (MLs) sputtered on combined Co18{angstrom}/Cu48{angstrom} buffer layer. GMR values at room temperature reach 62% at the first antiferromagnetically (AF) coupling peak and 33% at the 2nd AF coupled peak, which are very close to those found in Co/Cu MLs sputtered on a Fe buffer layer. The large GMR effect is attributed to the superior superlattice structure of these samples, as evidenced by the x-ray reflectivity data as well as the TEM micrographs. In particular, the role of thin Co initial layer deposited beneath the Cu buffer layer on improved ML structure has been clarified from cross-sectional micrographs of high-resolution TEM.

A computational model for the ablation of tooth enamel by ultra-short laser pulses is presented. The role of simulations using this model in designing and understanding laser drilling systems is discussed. Pulses of duration 300 fsec and intensity greater than 10{sup 12} W/cm{sup 2} are considered. Laser absorption proceeds via multi-photon initiated plasma mechanism. The hydrodynamic response is calculated with a finite difference method, using an equation of state constructed from thermodynamic functions including electronic, ion motion, and chemical binding terms. Results for the ablation efficiency are presented. An analytic model describing the ablation threshold and ablation depth is presented. Thermal coupling to the remaining tissue and long-time thermal conduction are calculated. Simulation results are compared to experimental measurements of the ablation efficiency. Desired improvements in the model are presented.

Predictions for NIF ICF target x-ray emission are presented. Validation experiments confirm the key features of the x-ray emissions and their effects on the NIF chamber B{sub 4}C first wall. Predictions of a possible first wall 0.35-{mu}m laser radiation compared to more experimental results conducted to determine B{sub 4}C response all suggest B{sub 4}C is an acceptable first wall material.

Explicit goals of acceptable risk for natural phenomena hazards (earthquake, extreme wind, and flood) have been established by the Department of Energy (DOE) 1994. Closely associated to the earthquake risk is the issue of seismically-induced liquefaction. Because deterministic methods currently available to answer the question to whether a site is liquefiable or not are incapable of providing a clue as to the likelihood or risk of liquefaction, the application of the criteria to a given facility requires that alternative evaluation techniques be formulated. This paper describes the application to a nuclear facility of a newly developed probabilistic methodology which rigorously accounts for geotechnical and seismologic uncertainties. The results of the analyses are compared with the acceptable levels of risk presented by DOE. This comparison is used to emphasize the power of the methodology as a tool in the decision-making processes.

A computational model for the ablation of tooth enamel by ultra-short laser pulses is presented. The role of simulations using this model in designing and understanding laser drilling systems is discussed. Pulses of duration 300 sec and intensity greater than 10{sup 12} W/cm{sup 2} are considered. Laser absorption proceeds via multi-photon initiated plasma mechanism. The hydrodynamic response is calculated with a finite difference method, using an equation of state constructed from thermodynamic functions including electronic, ion motion, and chemical binding terms. Results for the ablation efficiency are presented. An analytic model describing the ablation threshold and ablation depth is presented. Thermal coupling to the remaining tissue and long-time thermal conduction are calculated. Simulation results are compared to experimental measurements of the ablation efficiency. Desired improvements in the model are presented.

Many industrial applications require non-intrusive diagnostics for process monitoring and control. One example is the physical vapor deposition of titanium alloys. In this paper we present a system based on laser absorption spectroscopy for monitoring titanium vapor. Appropriate transitions for monitoring high rate vaporization of titanium require extension of available IR diode technology to the UV. The heart of this vapor density monitoring system is the 390nm radiation generated from quasi-phase matched interactions within periodically poled waveguides. In this paper, key system components of a UV laser absorption spectroscopy based system specific for titanium density monitoring are described. Analysis is presented showing the minimum power levels necessary from the ultraviolet laser source. Performance data for prototype systems using second harmonic generation (SHG) waveguide technology is presented. Application of this technology to other alloy density monitoring systems is discussed.

We have recently published an article in which we discuss means by which plutonium and other fissile material stored underground could reach criticality with positive feedback and therefore explosive potential. The Chernobyl rubble involving hundreds of tons of material is similar in some respects to the systems analyzed in the paper, and the practices there to control criticality may well increase the probability of a second event at Chernobyl 4. This paper explores the Chernobyl situation and remedial actions are recommended.

In this paper we present a user interface, CANDID Camera, for image retrieval using query-by-example technology. Included in the interface are several new layout algorithms based on multidimensional scaling techniques that visually display global and local relationships between images within a large image database. We use the CANDID project algorithms to create signatures of the images, and then measure the dissimilarity between the signatures. The layout algorithms are of two types. The first are those that project the all-pairs dissimilarities to two dimensions, presenting a many-to-many relationship for a global view of the entire database. The second are those that relate a query image to a small set of matched images for a one-to-many relationship that provides a local inspection of the image relationships. Both types are based on well-known multidimensional scaling techniques that have been modified and used together for efficiency and effectiveness. They include nonlinear projection and classical projection. The global maps are hybrid algorithms using classical projection together with nonlinear projection. We have developed several one-to-many layouts based on a radial layout, also using modified nonlinear and classical projection.

A preliminary design for a high-resolution transportable neutron radiography system concept has been developed. The system requirement has been taken to be a thermal neutron flux of 10{sup 6} N/(cm{sup 2}- sec) with an L/D of 100. The approach is to use an accelerator-driven neutron source, with a radiofrequency quadrupole (RFQ) as the primary accelerator component. Initial concepts for all of the major components of the system have been developed, and selected key parts have been examined further. An overview of the system design is presented, together with brief summaries of the concepts for the ion source, LEBT, RFQ, HEBT, target, moderator, collimator, image collection, power, cooling, vacuum, structure, robotics, control system, data analysis, transport vehicle, and site support. More detailed studies completed for the RFQ and moderator designs, and issues identified during the course of the work, are described.

There are three primary goals for the Neutron Activation system for ITER: maintain a robust relative measure of fusion power with stability and high dynamic range (7 orders of magnitude); allow an absolute calibration of fusion power (energy); and provide a flexible and reliable system for materials testing. The nature of the activation technique is such that stability and high dynamic range can be intrinsic properties of the system. It has also been the technique that demonstrated (on JET and TFTR) the highest accuracy neutron measurements in DT operation. Since the gamma-ray detectors are not located on the tokamak and are therefore amenable to accurate characterization, and if material foils are placed very close to the ITER plasma with minimum scattering or attenuation, high overall accuracy in the fusion energy production (7--10%) should be achievable on ITER. In the paper, a conceptual design is presented. A system is shown to be capable of meeting these three goals, also detailed design issues remain to be solved.

We have fabricated a novel GMR ML flux sensor that is designed to operate in the CPP mode. The GMR sensor is a 0.4 {mu}m diameter, 0.09 {mu}m high Cu-Co ML pedestal. The sensors are patterned using electron beam lithography. The Al{sub 2}O{sub 3}-TiC substrate is coated with a sputter deposited Al{sub 2}O{sub 3} film that is polished to <0.2 nm RMS roughness. Contact to the bottom of the GMR sensor is made by depositing the Cu-Co multilayers onto a smooth 0.45 {mu}m thick Mo-Si ML stack. The top contact is self-aligned to the GMR sensor. This is accomplished, in part, by CMP. The top and bottom contact layers are electrically isolated by a PECVD Si{sub 3}N{sub 4} film. The configuration of the contacts allows four point probe resistance measurements. The GMR response of these 0.4 {mu}m diameter sensors is 12%.

The effect that thermal loading has on the natural and engineered systems needs to be understood and demonstrated with reasonable assurance in the Viability Assessment and the License Application process for a potential underground high level waste repository at Yucca Mountain. Thermal loading can be defined in a number of ways but it basically is the amount of decay heat from the spent nuclear fuel produced per unit area and is related to the emplacement density of fuel. This paper provides an overview of the status of the development of the technical basis for a thermal loading decision for a potential repository at Yucca Mountain and emphasizes recent analyses conducted.