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Virtual Environments (VEs) have the potential to revolutionize traditional product design by enabling the transition from conventional CAD to fully digital product development. The presented prototype system targets closing the ''digital gap'' as introduced by the need for physical models such as clay models or mockups in the traditional product design and evaluation cycle. We describe a design environment that provides an intuitive human-machine interface for the creation and manipulation of three-dimensional (3D) models in a semi-immersive design space, focusing on ease of use and increased productivity for both designer and CAD engineers.

During the coming decade, high energy physics experiments at the Fermilab Tevatron and around the globe will use very sophisticated equipment to record unprecedented amounts of data in the hope of making major discoveries that may unravel some of Nature's deepest mysteries. The discovery of the Higgs boson and signals of new physics may be around the corner. The use of advanced analysis techniques will be crucial in achieving these goals. The author discusses some of the novel methods of analysis that could prove to be particularly valuable for finding evidence of any new physics, for improving precision measurements and for exploring parameter spaces of theoretical models.

We present a new method for simplifying large data sets that contain material interfaces. Material interfaces embedded in the meshes of computational data sets are often a source of error for simplification algorithms because they represent discontinuities in the scalar or vector fields over a cell. By representing material interfaces explicitly in a data simplification process, we are able to provide separate field representations for each material over a single cell and, thus, to represent the fields much more accurately. Our algorithm uses a multiresolution tetrahedral mesh supporting fast coarsening and refinement capabilities and error bounds for feature preservation. We represent a material interface or other surface of discontinuity as the zero set of a signed distance function. This representation makes it possible to maintain continuity of the surface across cell boundaries. It also makes it possible to represent more complex interface structures within a cell, such as T-intersections. Within a cell, a field is represented on either side of the surface of discontinuity by separate linear functions. These functions are determined by true and ''ghost'' values of the field at the vertices of the cell. By requiring that each vertex have only one ghost value for a given field …

We have successfully synthesized highly mismatched Cd{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys by high dose implantation of O ions into Cd{sub 1-y}Mn{sub y}Te crystals. In crystals with y > 0.02, incorporation of O causes a large decrease in the band gap. The band gap reduction increases with y; the largest value observed is 190 meV in O-implanted Cd{sub 0.38}Mn{sub 0.62}Te. The results are consistent with the band anticrossing model which predicts that a repulsive interaction between localized states of O located above the conduction band edge and the extended states of the conduction band causes the band gap reduction. A best fit of the measured band gap energies of the O ion synthesized Cd{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys using the band anticrossing model for y < 0.55 suggests an activation efficiency of only {approx}5% for implanted O in Cd{sub 1-y}Mn{sub y}Te.

Experiments to study beam dynamics for Relativistic Klystrons (RK) are being performed with a 1-MeV, 600-A induction accelerator beam. The RK is a RF Power source based on induction accelerator technology and conventional resonant output structures. Capable of generating 100's of MW/m at frequencies up to K-band, the RK has been proposed as a driver for a future linear collider in one version of a Two-Beam Accelerator. A critical feasibility issue remaining to be demonstrated is suppression of the transverse instability of the drive beam. This kiloampere beam must transit about a hundred resonance output structures and many hundreds of induction accelerator cavities for the RK to achieve competitive efficiency and cost with respect to other proposed power sources. The RK's strong focusing used to contain the beam in the small aperture resonant structures, repetitive geometry, and reacceleration allow the resonant output structures to be spaced at a betatron phase advance of 360{sup o}. This phase advance (or any integral multiple of 180{sup o}) is beneficial in linear accelerators as the instability growth changes from exponential to linear. In our experiment the beam is contained in a solenoidal focusing channel, RF cavities are spaced every 60 cm, and growth in …

Boron K-edge soft x-ray emission and absorption are used to address the fundamental question of whether divalent hexaborides are intrinsic semimetals or defect-doped bandgap insulators. These bulk sensitive measurements, complementary and consistent with surface-sensitive angle-resolved photoemission experiments, confirm the existence of a bulk band gap and the location of the chemical potential at the bottom of the conduction band.

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Several proof-of-principle laser accelerator experiments turned a long-wavelength of a CO{sub 2} laser to advantage. Ongoing advancement to multi-terawatt femtosecond CO{sub 2} lasers opens new venues for next-generation laser acceleration research.

It is shown that the two interactive strength parameters in the Tsai-Wu tensor polynomial strength criterion for fiber composites can be derived in terms of the uniaxial or non-interacting strength parameters if the composite does not fail under practical levels of hydrostatic pressure or equal transverse compression. Thus the required number of parameters is reduced from seven to five and all five of the remaining strength terms are easily determined using standard test methods. The derived interactive parameters fall within the stability limits of the theory, yet they lead to open failure surfaces in the compressive stress quadrant. The assumptions used to derive the interactive parameters were supported by measurements for the effect of hydrostatic pressure and unequal transverse compression on the behavior of a typical carbon fiber composite.

This paper introduces the DesignersWorkbench, a semi-immersive virtual environment for two-handed modeling, sculpting and analysis tasks. The paper outlines the fundamental tools, design metaphors and hardware components required for an intuitive real-time modeling system. As companies focus on streamlining productivity to cope with global competition, the migration to computer-aided design (CAD), computer-aided manufacturing (CAM), and computer-aided engineering (CAE) systems has established a new backbone of modern industrial product development. However, traditionally a product design frequently originates from a clay model that, after digitization, forms the basis for the numerical description of CAD primitives. The DesignersWorkbench aims at closing this technology or ''digital gap'' experienced by design and CAD engineers by transforming the classical design paradigm into its filly integrated digital and virtual analog allowing collaborative development in a semi-immersive virtual environment. This project emphasizes two key components from the classical product design cycle: freeform modeling and analysis. In the freeform modeling stage, content creation in the form of two-handed sculpting of arbitrary objects using polygonal, volumetric or mathematically defined primitives is emphasized, whereas the analysis component provides the tools required for pre- and post-processing steps for finite element analysis tasks applied to the created models.

We present a detailed analysis of K-shell emission from laser-produced rapidly-expanding aluminum plasmas. This work forms part of a series of experiments performed at the Vulcan laser facility of the Rutherford Appleton Laboratory, UK. 1-D planar expansion was obtained by over-illuminating Al-microdot targets supported on CH plastic foils. The small size of the Al-plasma ensured high spatial and frequency resolution of the spectra, obtained with a single crystal spectrometer, two vertical dispersion variant double crystal spectrometers, and a vertical dispersion variant Johann Spectrometer. The hydrodynamic properties of the plasma were measured independently by spatially and temporally resolved Thomson scattering, utilizing a 4{omega} probe beam. This enabled sub- and super- critical densities to be probed relative to the 1{omega} heater beams. The deduced plasma hydrodynamic conditions are compared with those generated from the 1-D hydro-code Medusa, and the significant differences found in the electron temperature discussed. Synthetic spectra generated from the detailed term collisional radiative non-LTE atomic physics code Fly are compared with the experimental spectra for the measured hydrodynamic parameters, and for those taken from Medusa. Excellent agreement is only found for both the H- and He-like Al series when careful account is taken of the temporal evolution of the …

A 220 m long ionization cooling system consisting of three solenoids with two field-flip sections, is proposed as a cooling channel for the neutrino factory. The reduction of transverse emittance is achieved using 87 liquid hydrogen absorbers (30-40 cm long), and 87 (2 m long) 200 MHz linacs. The first flip is performed at relatively small magnetic field, B = 3 T, to keep the longitudinal motion under control. The field is then increased adiabatically up to 7 T and a second field flip performed. The cooler was studied and simulated in detail. Preceded by a 16 GeV proton driver, a carbon target, a mini-cooler and a buncher, the system provides about 0.082 muons per incident proton.

A research and development program is underway to construct superconducting cavities to be used for radiofrequency separation of a Kaon beam at Fermilab. The design calls for installation of twelve 13-cell cavities operating in the 3.9 GHz transverse mode with a deflection gradient of 5 MV/m. They present the mechanical, cryogenic and vacuum design of the cavity, cryomodule, rf power coupler, cold tuner and supporting hardware. The electromagnetic design of the cavity is presented in a companion paper by Wanzenberg and McAshan. The warm tuning system (for field flatness) and the vertical test system is presented along with test results of bench measurements and cold tests on single-cell and five-cell prototypes.

Flow and solute transport through porous medium with strongly varying hydraulic conductivity are studied by numerical simulations. The heterogeneity of the porous medium is defined by {sigma} and {lambda}{prime}, which are, respectively, the standard deviation of natural log of permeability values and its correlation range {lambda} divided by transport distance L. The development of flow channeling as a function of these two parameters is demonstrated. The results show that for large heterogeneities, the flow is highly channelized and solute is transported through a few fast paths, and the corresponding breakthrough curves show a high peak at very early times, much shorter than the mean residence time. This effect was studied for a converging radial flow, to simulate tracer tests in a fracture zone or contact-thickness aquifer. It is shown that {sigma}{sup 2}{lambda}{prime} is an appropriate parameter to characterize the tracer dispersion and breakthrough curves. These results are used to study tracer breakthrough data from field experiments performed with nonsorbing tracers. A new procedure is proposed to analyze the results. From the moments of the residence-time distribution represented by the breakthrough curves, the heterogeneity of the porous medium, as characterized by {sigma}{sup 2}{lambda}{prime} and the mean residence time t{sub o}, may …

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A scenario for capture, bunching and rf rotation of {mu}'s from a proton source is presented. It consists of a drift section, a variable frequency {approximately} 300 {r_arrow} 180 MHz bunching section, and a fixed (or variable) frequency ({approximately}180 MHz) {phi}-{delta}E rotation section. In 1-D and 3-D simulations (SIMUCOOL and ICOOL), the overall capture performance of the system is similar to that of induction linac + buncher scenarios developed for the neutrino factory. The total rf required for the system is quite modest. Optimization procedures are described.

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A remote data acquisition chassis, called a HOTLink Rack Monitor, HRM, has been developed for use in the Fermilab control system. This chassis provides for 64 analog input channels, 8 analog output channels, and 8 bytes of digital I/O. The interface to the host VMEbus crate is by way of a 320 MHz HOTLink serial connection to a PMC mezzanine module. With no processor intervention, all data sources in the remote chassis are read at 100 sec intervals, time stamped, and stored in a 2 MB circular buffer on the PMC module. In operation, the memory always contains the most recent 16 k samples of 10 kHz data from all 64 analog input channels. An expansion module that resides in the HRM chassis records snapshot data for 8 analog channels, each channel consisting of up to 16 k readings, digitized at rates up to 10 MHz. Snapshot data is also returned and stored in buffers on the PMC module. Because the HRM presents a memory-mapped interface to the host, it is independent of the operating system and may be used in any system that supports PMC mezzanine modules.

Validation of Building Energy Simulation Programs consists of a combination of empirical validation, analytical verification, and comparative analysis techniques (Judkoff 1988). An analytical verification and comparative diagnostic procedure was developed to test the ability of whole-building simulation programs to model the performance of unitary space-cooling equipment that is typically modeled using manufacturer design data presented as empirically derived performance maps. Field trials of the method were conducted by researchers from nations participating in the International Energy Agency (IEA) Solar Heating and Cooling (SHC) Programme Task 22, using a number of detailed hourly simulation programs from Europe and the United States, including: CA-SIS, CLIM2000, PROMETHEUS, TRNSYS-TUD, and two versions of DOE-2.1E. Analytical solutions were also developed for the test cases.

We report a new measurement of the pseudorapidity ({eta}) and transverse-energy (E{sub T}) dependence of the inclusive jet production cross section in p{bar p} collisions at {radical}s = 1:8 TeV using 95 pb{sup {minus}1} of data collected with the D0 detector at the Fermilab Tevatron. The differential cross section d{sup 2}{sigma}/(dE{sub T}d{eta}) is presented up to {vert_bar}{eta}{vert_bar} = 3, significantly extending previous measurements. The results are in good overall agreement with next-to-leading order predictions from QCD, indicate a preference for certain parton distribution functions, and provide the world's best constraint on the gluon distribution at high parton momentum fraction x.

We present a measurement of the W boson mass in proton-antiproton collisions at {radical}s = 1.8 TeV based on a data sample of 82 pb{sup -1} integrated luminosity collected by the D0 detector at the Fermilab Tevatron. We utilize e{nu} events in which the electron shower is close to the phi edge of one of the 32 modules in the D0 central calorimeter. The electromagnetic calorimenter response and resolution in this region differs from that in the rest of the module and electrons in this region were not previously utilized. We determine the calorimeter response and resolution in this region using Z {yields} ee events. We extract the W boson mass by fitting to the transverse mass and to the electron and neutrino transverse momentum distributions. The result is combined with previous D0 results to obtain an improved measurement of the W boson mass: m{sub W} = 80.483 {+-} 0.084 GeV.

Many scientific applications are I/O-intensive, which makes optimization and scaling difficult, especially on parallel architectures. The I/O requirements of computational biology applications are different from other scientific applications. The main difference is that many computational biology applications are embarrassingly parallel and require repeated read-only access to a large global database. In this paper we examine the scalability of an embarrassingly parallel computational biology application: psLayout, which played a crucial role in the mapping of the human genome. This study was carried out on three architecture: the native UCSC Linux cluster, a Linux cluster at Lawrence Livermore National Labs with a faster interconnect and NFS server, and the ASCI Blue-Pacific supercomputer. We show that a cluster equipped with a fast network and parallel file system or a scalable NFS server has reasonable I/O scalability. We believe that replication is an important issue when scaling to larger numbers of processors, and we introduce the design of a library for automatic data replication to address this issue.

Complex surfaces and solids are produced by large-scale modeling and simulation activities in a variety of disciplines. Productive interaction with these simulations requires that these surfaces or solids be viewable at interactive rates--yet many of these surfaced solids can contain hundreds of millions of polygondpolyhedra. Interactive display of these objects requires compression techniques to minimize storage, and fast view-dependent triangulation techniques to drive the graphics hardware. In this paper, we review recent advances in subdivision-surface wavelet compression and optimization that can be used to provide a framework for both compression and triangulation. These techniques can be used to produce suitable approximations of complex surfaces of arbitrary topology, and can be used to determine suitable triangulations for display. The techniques can be used in a variety of applications in computer graphics, computer animation and visualization.