The interaction of subpicosecond 1.06 mm laser light at intensities up to 10{sup 18} W/cm{sup 2} with dense performed plasmas is investigated by measurements of the absorption of the laser light in the plasma and by measurements of the production of bremsstrahlung x-rays. Absorption measurements are made by collecting the scattered light in an Ulbricht sphere. Light scattered in the backward and specular directions is collected separately. Measurements are presented for both high and low Z targets. X-ray production is measured using a nine channel filter/scintillator spectrometer.

ACHRO is a very simple 2000-line. FORTRAN code that provides help for the designer of the achromatic bend. Given a beam momentum, the program calculates the required drift lengths and dipole parameters which it will apply to any one of several different types of achromats. The types of achromats that the code helps to design include the Enge dual-270,`` the Brown 2-dipole, the Leboutet 3-dipole, and the Enge 4-dipole, as well as the periodic systems which can be designed to any order in symmetric, nonsymmetric and stair-step varieties. Given the dimensions into which a bend must fit, ACHRO will calculate the geometrical parameters in an X-Y plane for a single or multiple achromat, and for achromatic ``S-bend`` configurations where possible. ACHRO makes it very easy to optimize a bend with respect to drift lengths and magnet parameters by allowing the user to change parameter values and see the resulting calculation. Used in conjunction with a beam-transport code, ACHRO makes it possible for a designer to consider various types of achromatic bends in the same beamline layout in order to compare important bend characteristics such as dispersion, Isochronicity, sensitivity, geometric and chromatic aberrations, aperture requirements, space for diagnostics, etc., all of …

Path planning has to be fast to support real-time robot programming. Unfortunately, current planning techniques are still too slow to be effective, as they often require several minutes, if not hours of computation. To alleviate this problem, we present a learning algorithm that uses past experience to enhance future performance. The algorithm relies on an existing path planner to provide solutions to difficult tasks. From these solutions, an evolving sparse network of useful subgoals is learned to support faster planning. The algorithm is suitable for both stationary and incrementally-changing environments. To analyze our algorithm, we use a previously developed stochastic model that quantifies experience utility. Using this model, we characterize the situations in which the adaptive planner is useful, and provide quantitative bounds to predict its behavior. The results are demonstrated with problems in manipulator planning. Our algorithm and analysis are sufficiently general that they may also be applied to task planning or other planning domains in which experience is useful.

About sixteen years ago, Bengt Carlson introduced a method for discretizing the neutral particle transport equation to achieve a positive solution while at the same time retaining much of the accuracy of the diamond differencing method. About six years later Russian researchers applied this work to their problems and extended it somewhat to enhance the flexibility of the method to incorporate monotonic properties of the solution. This latter work came to the attention of US researchers in late 1991 where it verified much of Carlson`s conclusions in theory and in test problems. This method, called the adaptive weighted diamond (AWDD) method, is based upon a weighted diamond discretization of the transport equation with the weights chosen from a diamond difference prediction of the solution so as to correct it for positively and monotonicity. This work re-examines the method and extends it to three-dimensional XYZ geometry and demonstrates its potential for solving such problems accurately while achieving a much smoother solution than diamond with set-to-zero fixup and is as effective as the theta-weighted fixup method 3 while theoretically and operationally more satisfying.

There are many well developed codes available for beamline design and analysis. A significant fraction of each of these codes is devoted to processing its own unique input language for describing the problem. None of these large, complex, and powerful codes does everything. Adding a new bit of specialized physics can be a difficult task whose successful completion makes the code even larger and more complex. This paper describes an attempt to move in the opposite direction, toward a family of small, simple, single purpose physics and utility modules, linked by an open, portable, public domain database framework. These small specialized physics codes begin with the beamline parameters already loaded in the database, and accessible via the handful of subroutines that constitute ADLIB. Such codes are easier to write, and inherently organized in a manner suitable for incorporation in model based control system algorithms. Examples include programs for analyzing beamline misalignment sensitivities, for simulating and fitting beam steering data, and for translating among MARYLIE, TRANSPORT, and TRACE3D formats.

The development and utilization of advanced computing and communications technologies are accelerating rapidly, particularly under the influence of the recently initiated Federal High Performance Computing and Communications Program. The nuclear power industry has traditionally been on the forefront of such advanced computing technologies. This paper will illustrate several of the developments and future opportunities for utilization of these technologies for addressing grand challenges of the nuclear power industry. The specific capabilities of evolving scientific workstations, network based computing and parallel processing will be illustrated.

A computerized control system has been developed for the remotely-operated fuel pin processor used in the Integral Fast Reactor Program, Fuel Cycle Facility (FCF). The pin processor remotely shears cast EBR- reactor fuel pins to length, inspects them for diameter, straightness, length, and weight, and then inserts acceptable pins into new sodium-loaded stainless-steel fuel element jackets. Two main components comprise the control system: (1) a programmable logic controller (PLC), together with various input/output modules and associated relay ladder-logic associated computer software. The PLC system controls the remote operation of the machine as directed by the OCS, and also monitors the machine operation to make operational data available to the OCS. The OCS allows operator control of the machine, provides nearly real-time viewing of the operational data, allows on-line changes of machine operational parameters, and records the collected data for each acceptable pin on a central data archiving computer. The two main components of the control system provide the operator with various levels of control ranging from manual operation to completely automatic operation by means of a graphic touch screen interface.

This paper describes several large-scale computational models developed at Argonne National Laboratory for the simulation and analysis of thermal-hydraulic and neutronic events in nuclear reactors and nuclear power plants. The impact of advanced parallel computing technologies on these computational models is emphasized.

This report discusses the following on Los Alamos National Laboratory: laboratory mission with physics and life sciences goals; physics and life sciences quality requirements and guidance documents basis; process flow-down of documentation; line-organization internal and external assessments; laboratory management issues under development; and the quality assurance management plan.

A hydrodynamic method has been employed to align short, reinforcing fibers in polymer matrix composite materials. Samples of composite materials were prepared and tested two at a time (one with randomly oriented fibers and the other with aligned fibers) to isolate and directly measure the effect on mechanical properties of aligning the fibers. Data were collected for the ultimate tensile strength, modulus of elasticity, and ultimate tensile strain of the composite samples prepared. Results show that the aligned fibers were approximately twice as effective (as randomly oriented fibers) at stiffening and strengthening the composite in the alignment direction. 5 figs, 20 refs.

The Ion Micro-Analysis Group (IMAG) in Livermore conducts quantitative trace elemental analysis with PIXE and depth profiling with IBS using an MeV ion microbeam. The system has the capability to produce two-dimensional trace element and IBS images. PIXE analyses have been conducted on HgI{sub 2} and PbI{sub 2} crystals and detector materials in order to identify and quantify near surface trace contaminants. IBS measurements have been conducted to investigate elemental depth distributions in various materials. The results of measurements on several different samples are reported and a discussion of factors affecting quantitative in vacuo microanalysis of these materials is presented.

Resonance Raman spectroscopy (RRS) potentially possesses many of the characteristics of an ideal verification technology. Some of these ideal traits are: very high selectivity and specificity to allow the deconvolution of a mixture of the chemicals of interest, high sensitivity in order to measure a species at trace levels, high reliability and long-term durability, applicability to a wide range of chemicals capability for sensing in a variety of environmental conditions, independence of the physical state of the chemical capability for quantitative analysis, and finally, but no less important capability for full signal development within seconds. In this presentation, the potential of RRS as a detection/identification technology for chemicals pertinent to nuclear materials production and processing will be assessed. A review of the basic principles behind this technique, both theoretical and experimental, will be discussed along with some recent results obtained in this laboratory. Raman scattering is a coherent, inelastic, two-photon scattering process where an exciting photon of energy hv promotes a molecule to a virtual level and the subsequently emitted photon is shifted in frequency in accordance with the rotational-vibrational structure of the irradiated species, therefore providing a unique fingerprint of the molecule. The enhancement of a Raman signal occurs …

It has been suggested for some time that microwave reflectometry, has the potential for measuring the large scale structure of density fluctuations in tokamak turbulence with greatly improved spatial resolution over existing scattering techniques. The motivation for developing fluctuation diagnostics with improved spatial resolution of large scale structures is that such fluctuations may potentially account for the anomalous particle and energy transport observed in tokamaks. On TFTR we now have operational a four channel X-mode reflectometer system comprising of three fixed frequency channels at 140, 132.5, and 125 GHz and a able frequency channel scanning between 110--123 GHz. Each channel detects fluctuations from a region on the equatorial plane of the plasma torus with spatial resolution of [approx]5 cm in the poloidal direction and [approx]1 cm in the radial direction. Properties of the plasma turbulence are inferred from the amplitude and spectral coherence of phase fluctuations impressed on the reflected wave by density irregularities at or near the cutoff. Experimental results are presented which show the existence of previously unobserved large scale (k[perpendicular][rho][sub i]<<1) random and coherent density fluctuations in the Ohmic and Supershot regimes of TFTR.

It has been suggested for some time that microwave reflectometry, has the potential for measuring the large scale structure of density fluctuations in tokamak turbulence with greatly improved spatial resolution over existing scattering techniques. The motivation for developing fluctuation diagnostics with improved spatial resolution of large scale structures is that such fluctuations may potentially account for the anomalous particle and energy transport observed in tokamaks. On TFTR we now have operational a four channel X-mode reflectometer system comprising of three fixed frequency channels at 140, 132.5, and 125 GHz and a able frequency channel scanning between 110--123 GHz. Each channel detects fluctuations from a region on the equatorial plane of the plasma torus with spatial resolution of {approx}5 cm in the poloidal direction and {approx}1 cm in the radial direction. Properties of the plasma turbulence are inferred from the amplitude and spectral coherence of phase fluctuations impressed on the reflected wave by density irregularities at or near the cutoff. Experimental results are presented which show the existence of previously unobserved large scale (k{perpendicular}{rho}{sub i}<<1) random and coherent density fluctuations in the Ohmic and Supershot regimes of TFTR.

This paper addresses the problem of obtaining meaningful data from samples of solid heterogeneous waste while maintaining sample rates as low as practical. The Waste Receiving and Processing Facility, Module 1, at the Hanford Site in south-central Washington State will process mostly heterogeneous solid wastes. The presence of hazardous materials is documented for some packages and unknown for others. Waste characterization is needed to segregate the waste, meet waste acceptance and shipping requirements, and meet facility permitting requirements. Sampling and analysis are expensive, and no amount of sampling will produce absolute certainty of waste contents. A sampling strategy is proposed that provides acceptable confidence with achievable sampling rates.

This presentation encourages current efforts in arms control, non- proliferation, and peacekeeping. Verification is heralded as a confidence building method to bring about more openness in international relations. It is purported that openness has already enhanced democratic forces around the world. The insistence on strict compliance with the decisions of the United Nations Security Council is a show of support for international law. It is recommended that international norms on human rights, non-proliferation, and non-aggression be strengthened.

The possible impact of nitrogen-cooled superconductors on the desip and cost of superconducting fault-current limiters is assessed by considering the technical specifications such devices must meet and by comparing material properties of 77-K and 4-K superconductors. The main advantages of operating superconductors at 77 K are that the refrigeration operating cost is reduced by a factor of up to 25 and the refrigeration capital cost is reduced by a factor of up to 10. The heat capacity is several orders of magnitude Larger at 77 K and at 4 K. This phenomenon increases conductor stability against flux jumps but makes switching from the superconducting to the normal state slow and difficult. Therefore, a high critical current density, probably at least 10{sup 5} A/cm{sup 2}, is required.

User Services groups are on the front line with user support. We are the first to hear about problems. The speed, accuracy, and intelligence with which we respond determines the user`s perception of our effectiveness and our commitment to quality and service. To keep pace with the complex changes at our sites, we must have tools to help build a knowledge base of solutions, a history base of our users, and a record of every problem encountered. Recently, I completed a survey of twenty sites similar to the National Energy Research Supercomputer Center (NERSC). This informal survey reveals that 27% of the sites use a paper system to log calls, 60% employ homegrown automated call tracking systems, and 13% use a vendor-supplied system. Fifty-four percent of those using homegrown systems are exploring the merits of switching to a vendor-supplied system. The purpose of this paper is to provide guidelines for evaluating a call tracking system. In addition, insights are provided to assist User Services groups in selecting a system that fits their needs.

The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout.

This article is a personal perspective about the physics of the beam-beam interaction. This is an active area of research combining operational experience, experiments, computer models, and theory with the goal being to overcome the shortcomings above. This research hasn't progressed sufficiently to quantitatively explain beam-beam limits, but there are qualitative explanations of many of the features of the beam-beam interaction and clear directions for future developments.

This article is a personal perspective about the physics of the beam-beam interaction. This is an active area of research combining operational experience, experiments, computer models, and theory with the goal being to overcome the shortcomings above. This research hasn`t progressed sufficiently to quantitatively explain beam-beam limits, but there are qualitative explanations of many of the features of the beam-beam interaction and clear directions for future developments.

Waste matrices containing organics, radionuclides, and metals pose difficult problems in waste treatment and disposal when the organic compounds and/or metals are considered to be hazardous. A means of destroying hazardous organic components while safely containing and concentrating metals would be extremely useful in mixed waste volume reduction or conversion to a radioactive-only form. Previous studies have found the DETOX, a patented process utilizing a novel catalytic wet oxidation by iron(III) oxidant, cold have successful application to mixed wastes, and to many other waste types. This paper describes the results of bench scale studies of DETOX applied to the components of liquid mixed wastes, with the goal of establishing parameters for the design of a prototype waste treatment unit. Apparent organic reaction rate orders, and the dependence of apparent reaction rate on the contact area, were measured for vacuum pump oil, scintillation fluids, and trichloroethylene. It was found that reaction rate was proportional to contact area above about 2.% w/w loading of organic. Oxidations in a 4 liter. volume, mixed bench top reactor have given destruction efficiencies of 99.9999+% for common organics. Reaction rates achieved in the mixedbench top reactor were one to two orders of magnitude greater than had …

To satisfy the need for the verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for an advanced boding water reactor standard design, three piping benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the advanced reactor standard design. It will be required that the combined license holders demonstrate that their solutions to these problems are in agreement with the benchmark problem set. A summary description of each problem and some sample results are included.

Recent developments in pursuance of the 17-keV neutrino are reviewed. Several different experiments found anomalies in {beta} decay spectra which were consistently interpreted as evidence for a heavy neutrino. On the other hand, recent null results definitively rule out the existence of a 17-keV neutrino, as well as escaping criticisms applicable to earlier experiments. While missing links remain, it seems that any strong evidence for a 17-keV neutrino has vanished. Specifically, the anomalies observed in {sup 35}S and {sup 63}Ni spectra at Oxford can be reinterpreted in terms of electron scattering effects. In addition, the discrepancy amongst internal bremsstrahlung measurements has an instrumental origin, and recent results disfavour a 17-keV neutrino. Anomalies persist in the low energy region of the tritium spectrum which deserve further investigation.