We address the semirelativistic constituent-quark model with linear confinement and a hyperfine interaction deduced from Goldstone-boson exchange. In the version where the latter is represented by pseudoscalar meson exchange ({pi}, K, {eta}, {eta}{prime})and restricted to the spin-spin component only a unified description of all light- and strange-baryon spectra is provided in close agreement with phenomenology. We discuss the extension of the model that includes also the tensor components of the pseudoscalar meson exchange and in addition vector-meson ({rho}, {omega}, K*, {phi}) and scalar-meson ({sigma}) exchanges. A preliminary version thereof provides a description of the baryon spectra with similar good quality.

The couplings among chemical reaction rates, advective and diffusive transport in fractured media or soils, and changes in hydraulic properties due to precipitation and dissolution within fractures and in rock matrix are important for both nuclear waste disposal and remediation of contaminated sites. This paper describes the development and application of LEHGC2.0, a mechanistically-based numerical model for simulation of coupled fluid flow and reactive chemical transport including both fast and slow reactions invariably saturated media. Theoretical bases and numerical implementations are summarized, and two example problems are demonstrated. The first example deals with the effect of precipitation-dissolution on fluid flow and matrix diffusion in a two-dimensional fractured media. Because of the precipitation and decreased diffusion of solute from the fracture into the matrix, retardation in the fractured medium is not as large as the case wherein interactions between chemical reactions and transport are not considered. The second example focuses on a complicated but realistic advective-dispersive-reactive transport problem. This example exemplifies the need for innovative numerical algorithms to solve problems involving stiff geochemical reactions.

The electrical conductivities of boron carbides, B{sub 12+x}C{sub 3{minus}x} with 0.1 < x < 1.7, between 300 and 1200K suggest the hopping of a nearly temperature-independent density of small (bi)polarons. The activation energies of the nobilities are low, {approx} 0.16 eV, and are nearly independent of the composition. At lower temperatures, conductivities have non-Arrhenius temperature dependencies and strong sensitivity to carbon concentration. Percolative aspects of low-temperature hopping are evident in this sensitivity to composition. Boron carbides' Seebeck coefficients are anomalous in that (1) they are much larger than expected from boron carbides' large carrier densities and (2) they depend only weakly on the carrier density. Carrier-induced softening of local vibrations gives contributions to the Seebeck coefficient that mirror the magnitudes and temperature dependencies found in boron carbides.

The DOE Knowledge Base is a library of detailed information whose purpose is to improve the capability of the United States National Data Center (USNDC) to monitor compliance with the Comprehensive Test Ban Treaty (CTBT). Much of the data contained by the Knowledge Base is spatial in nature, and some of it is used to improve the accuracy with which seismic locations are determined while maintaining or improving current calculational perfor- mance. In this presentation, we define and describe the methodology used to create spatial tessellations of seismic data which are utilized with a gradient-modified natural-neighbor interpolation method to evaluate travel-time corrections. The goal is to interpolate a specified correction surface, or a group of them, with prescribed accuracy and surface smoothness requirements, while minimizing the number of data points necessary to represent the surface. Maintain- ing accuracy is crucial toward improving the precision of seismic origin location. Minimizing the number of nodes in the tessellation improves calculational and data access efficiency and performance. The process requires two initialization steps and an iterated 7 step algorithm for inserting new tessellation nodes. First, M residual data from ground truth events are included in the tessellation. These data remain fixed throughout the …

A code, SPINK, to track polarized particles in a circular accelerator, in particular RHIC [1], is been used to: find conditions for safely crossing depolarizing resonances, using Siberian Snakes; find the best conditions to match the spin of the injected beam to the ring lattice; study the operation of Spin Rotators and study the beam-beam effects in a polarized proton collider.

This paper describes the use of Fourier techniques to characterize the wavefront of optical components, specifically, the use of the power spectral density, (PSD), function. The PSDs of several precision optical components will be shown. Many of the optical components of interest to us have square, rectangular or irregularly shaped apertures with major dimensions up-to 800 mm. The wavefronts of components with non-circular apertures cannot be analyzed with Zernicke polynomials since these functions are an orthogonal set for circular apertures only. Furthermore, Zernicke analysis is limited to treating low frequency wavefront aberrations; mid-spatial scale and high frequency error are expressed only as ``residuals.`` A more complete and powerful representation of the optical wavefront can be obtained by Fourier analysis in 1 or 2 dimensions. The PSD is obtained from the amplitude of frequency components present in the Fourier spectrum. The PSD corresponds to the scattered intensity as a function of scattering angle in the wavefront and can be used to describe the intensity distribution at focus. The shape of a resultant wavefront or the focal spot of a complex multi-component laser system can be calculated and optimized using the PSDs of individual optical components which comprise it.

The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

A high current kicker has been designed and tested on the ETA-II beam line. A bias dipole which surrounds the kicker acts to deflect the beam in the DC mode. High voltage pulsers (10kV) with fast rise times (10ns) are connected to the internal strip lines of the kicker. They are used to manipulate beams dynamically. Camera photos which show the switching of the beam from one position to another will be presented. Beam bug measurements of beam-induced as well as active steering will be shown. These will be compared with theoretical predictions.

Aircraft and later missile radar early warning stations played an important role in the Cold War. They are associated with important technological, social, political, and military themes of the Cold War and are worthy of preservation. The scope and scale of these systems make physical preservation impractical, but the U.S. Air Force program of historical evaluation and documentation of these systems will provide valuable information to future generations studying this historic period.

Paul McWhorter, Deputy Director for of the Microsystems Center at Sandia National Laboratories, discusses the potential of surface micromachining. A vision of the possibilities of intelligent Microsystems for the future is presented along with descriptions of several possible applications. Applications that are just around the corner and some that maybe quite a ways down the road but have a clear development path to their realization. Microsystems will drive the next silicon revolution.

The powder-in-tube (PIT) technique was used to fabricate multifilament (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (Bi-2223) superconducting tapes. Transport current properties of these tapes were enhanced by increasing the packing density of the precursor powder and improving the mechanical deformation condition. A critical current (I{sub c}) of > 35 A in long lengths (> 200 m) tapes has been achieved. In measuring the dependence of critical current density on magnetic field and temperature for the optimally processed tapes, we found a J{sub c} of > 10{sup 4} A/cm{sup 2} at 20 K in magnetic fields up to 3 T and parallel to the c-axis, which is of interest for use in refrigerator-cooled magnets. I{sub c} declined exponentially when an external field was applied perpendicular to the tape surface at 77 K. Mechanical stability was tested for tapes sheathed with pure Ag and Ag-Mg alloy. Tapes made with pure Ag sheathing can withstand a tensile stress of {approx}20 MPa with no detrimental effect on I{sub c} values. Mechanical performance was improved by using Ag-Mg alloy sheathing: values of transport critical current began to decrease at the tensile stress of {approx} 100 MPa. Transport current measurements on tapes wound on a mandrel …

This report presents progress made on a technique for {sup 14}C dating pictographs. A low-temperature oxygen plasma is used coupled with high-vacuum technologies to selectively remove C-containing material in the paints without contamination from inorganic carbon from rock substrates or accretions.

In this lecture, a limited introduction of gauge invariance in phase-space is provided, predicated on canonical transformations in quantum phase-space. Exact characteristic trajectories are also specified for the time-propagating Wigner phase-space distribution function: they are especially simple--indeed, classical--for the quantized simple harmonic oscillator. This serves as the underpinning of the field theoretic Wigner functional formulation introduced. Scalar field theory is thus reformulated in terms of distributions in field phase-space. This is a pedagogical selection from work published and reported at the Yukawa Institute Workshop ''Gauge Theory and Integrable Models'', 26-29 January, 1999.

Liquid crystal spatial light modulator technology appropriate for high-resolution wavefront control has recently become commercially available. Some of these devices have several hundred thousand controllable degrees of freedom, more than two orders of magnitude greater than the largest conventional deformable mirror. We will present results of experiments to characterize the optical properties of these devices and to utilize them to correct aberrations in an optical system. We will also present application scenarios for these devices in high-power laser systems.

The CDF experiment at the Fermilab Tevatron has proven to be well suited for precision studies of b physics. Thanks to the excellent performance of the Tevatron Collider and the detector, CDF has accumulated very large data samples and roughly a decade of experience with b physics in p{bar p} collisions. With the much higher luminosities expected for the Main Injector era, the next decade promises to be an even more fruitful period for CDF. Here we offer a brief overview of issues in hadron-collider b physics and a summary of CDF's accomplishments and future plans.

The DOE Knowledge Base is a library of detailed information whose purpose is to support the United States National Data Center (USNDC) in its mission to monitor compliance with the Comprehensive Test Ban Treaty (CTBT). One of the important tasks which the USNDC must accomplish is to periodically perform detailed analysis of events of high interest, so-called "Special Events", to provide the national authority with information needed to make policy decisions. In this paper we investigate some possible uses of the Knowledge Base for Special Event Analysis (SEA), and make recommendations for improving Knowledge Base support for SEA. To analyze an event in detail, there are two basic types of data which must be used sensor-derived data (wave- forms, arrivals, events, etc.) and regiohalized contextual data (known sources, geological characteristics, etc.). Cur- rently there is no single package which can provide full access to both types of data, so for our study we use a separate package for each MatSeis, the Sandia Labs-developed MATLAB-based seismic analysis package, for wave- form data analysis, and ArcView, an ESRI product, for contextual data analysis. Both packages are well-suited to pro- totyping because they provide a rich set of currently available functionality and yet …

A computational fluid dynamic (CFD) computer code was used to determine the effects of product yields of three feed injection parameters in a fluidized catalytic cracking (FCC) riser reactor. This study includes the effects of both symmetrical and non-symmetrical injection parameters. All these parameters have significant effects on the feed oil spray distribution, vaporization rates and the resulting product yields. This study also indicates that optimum parameter ranges exist for the investigated parameters.

Slow-positron beams produced from negative-work-function solid-state moderators have found numerous applications in condensed matter physics. There are potential advantages in using low-energy primary electron beams for positron production, including reduced radiation damage to single-crystal moderators and reduced activation of nearby components. We present numerical calculations of positron yields and other beam parameters for various target-moderator configurations using the Argonne Wakefield Accelerator (AWA) [1] and Advanced Photon Source (APS) [2] electron linacs [3] as examples of sources for the primary electron beams. The status of experiments at these facilities is reviewed.

With recent developments, X-ray beam position monitors (BPMs) are capable of making accurate photon position measurements down to the sub-micron level. The true performance of X-ray beam position monitors when installed on insertion device beamlines is, however, severely limited due to the stray radiation traveling along the beamline that contaminates the insertion device photons. The stray radiation emanates from upstream and downstream dipole magnet fringe fields, from steering correctors, and from sextupoles and quadrupoles with offset trajectories. While significant progress has been made at the APS using look-up tables derived from translation stage scans to compensate for this effect, performance of ID X-BPMs to date is at the 10 to 20 micron level. A research effort presently underway to address this issue involves the introduction of a chicane into the accelerator lattice to steer the stray radiation away from the X-ray BPM blades. A horizontal parallel translation of the insertion device allows only ID photons and radiation from two nearby correctors to travel down the beamline, simplifying the radiation pattern considerably. A detailed ray tracing analysis has shown that stray radiation gets displaced by up to 2 cm horizontally at the X-BPM locations so that it can be easily masked. …

The U.S. National Laboratories, under the auspices of the Department of Energy, have been tasked with improv- ing the capability of the United States National Data Center (USNDC) to monitor compliance with the Comprehen- sive Test Ban Trea~ (CTBT). One of the most important services which the USNDC must provide is to locate suspicious events, preferably as accurately as possible to help identify their origin and to insure the success of on-site inspections if they are deemed necessary. The seismic location algorithm used by the USNDC has the capability to generate accurate locations by applying geographically dependent travel time corrections, but to date, none of the means, proposed for generating and representing these corrections has proven to be entirely satisfactory. In this presentation, we detail the complete DOE model for how regional calibration travel time information gathered by the National Labs will be used to improve event locations and provide more realistic location error esti- mates. We begin with residual data and error estimates from ground truth events. Our model consists of three parts: data processing, data storage, and data retrieval. The former two are effectively one-time processes, executed in advance before the system is made operational. The last step …

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The National Ignition Facility (NIF) is currently being constructed at Lawrence Livermore National Laboratory (LLNL). During peak operation, the NIF will attain D-T fusion yields of 20 MJ in a single experiment and 1200 MJ/y. With such high yields, neutron activation will be important within the NIF Target Bay. The total dose equivalent (dose) will be maintained {<=} 10 person-rem/y with individual doses {<=} 500 mrem/y, and all doses will be as low as reasonably achievable (ALARA). This work outlines planned maintenance activities, expected dose rates, and the resulting worker dose. Methods for the reduction of this dose are discussed, and a tool for the rapid calculation of the occupational dose is presented.

This paper describes the technical tasks being implemented to computerize the physical inventory taking (PIT) at the Mining and Chemical Combine (Gorno-Khimichesky Kombinat, GKhK) radiochemical plant under the US/Russian cooperative nuclear material protection, control, and accounting (MPC and A) program. Under the MPC and A program, Lab-to-Lab task agreements with GKhK were negotiated that involved computerized equipment for item verification and confirmatory measurement of the Pu containers. Tasks under Phase I cover the work for demonstrating the plan and procedures for carrying out the comparison of the Pu container identification on the container with the computerized inventory records. In addition to the records validation, the verification procedures include the application of bar codes and bar coded TIDs to the Pu containers. Phase II involves the verification of the Pu content. A plan and procedures are being written for carrying out confirmatory measurements on the Pu containers.

Results of experiments with the laser guide star adaptive optics system on the 3-meter Shane telescope at Lick Observatory have demonstrated a factor of 4 performance improvement over previous results. Stellar images recorded at a wavelength of 2 {micro}m were corrected to over 40% of the theoretical diffraction-limited peak intensity. For the previous two years, this sodium-layer laser guide star system has corrected stellar images at this wavelength to {approx}10% of the theoretical peak intensity limit. After a campaign to improve the beam quality of the laser system, and to improve calibration accuracy and stability of the adaptive optics system using new techniques for phase retrieval and phase-shifting diffraction interferometry, the system performance has been substantially increased. The next step will be to use the Lick system for astronomical science observations, and to demonstrate this level of performance with the new system being installed on the 10-meter Keck II telescope.