The production methods together with the achieved flatness and thickness of the composite support structures of the CMS tracker outer barrel (TOB) detector are presented. Possible areas of improvement in the process and in the materials used are also suggested.

The methods and codes employed in the U.S. Heavy Ion Fusion program to simulate the beams in an Integrated Research Experiments (IRE) facility and a fusion driver are presented in overview. A new family of models incorporating accelerating module impedance, multi-beam, and self-magnetic effects is described, and initial WARP3d particle simulations of beams using these models are presented. Finally, plans for streamlining the machine-design simulation sequence, and for simulating beam dynamics from the source to the target in a consistent and comprehensive manner, are described.

Energetic oxetane polymers have shown promise as performance-enhancing ingredients in gun and missile propellants. In order to correctly predict the performance of energetic materials containing these polymers, it is important to have accurate, experimentally determined values for the polymer heats of formation ({Delta}H{sub f}). In support of a theoretical study on gun propellant performance, heats of combustion were experimentally determined for a series of oxetane polymers and monomers (see below) using combustion calorimetry, and from these, {Delta}H{sub f} values were calculated. Polymers included BAMO/AMMO, BAMO/NMMO (polyol and TPE), and BNMO/NMMO mixtures. In order to calculate the {Delta}H{sub f} of the polymers from heat of combustion data, a number of assumptions were made regarding the polymer structure and molecular weight. A comparison of the {Delta}H{sub f} values for the monomers and polymers were made, and these values were compared to heats of formation measured elsewhere.

Underground coal mining (down to {approx}0.75 km depth) in the contiguous Wasatch Plateau (WP) and Book Cliffs (BC) mining districts of east-central Utah induces abundant seismicity that is monitored by the University of Utah regional seismic network. This report presents the results of a systematic characterization of mining seismicity (magnitude {le} 4.2) in the WP-BC region from January 1978 to June 2000-together with an evaluation of three seismic events (magnitude {le} 4.3) associated with underground trona mining in southwestern Wyoming during January-August 2000. (Unless specified otherwise, magnitude implies Richter local magnitude, M{sub L}.) The University of Utah Seismograph Stations (UUSS) undertook this cooperative project to assist the University of California Lawrence Livermore National Laboratory (LLNL) in research and development relating to monitoring the Comprehensive Test Ban Treaty (CTBT). The project, which formally began February 28, 1998, and ended September 1, 2000, had three basic objectives: (1) Strategically install a three-component broadband digital seismic station in the WP-BC region to ensure the continuous recording of high-quality waveform data to meet the long-term needs of LLNL, UUSS, and other interested parties, including the international CTBT community. (2) Determine source mechanisms--to the extent that available source data and resources allowed--for comparative seismic characterization …

In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

Optical coatings are a crucial part of the pulse trapping and extraction in the NIF multipass amplifiers. Coatings also steer the 192 beams from four linear arrays to four converging cones entering the target chamber. There are a total of 1600 physical vapor deposited coatings on NIF consisting of 576 mirrors within the multipass cavity, 192 polarizers that work in tandem with a Pockels cell to create an optical switch, and 832 transport mirrors. These optics are of sufficient size so that they are not aperture-limiting for the 40-cm x 40 cm beams over an incident range of 0 to 56.4 degrees. These coatings must withstand laser fluences up to 25 J/cm{sup 2} at 1053 nm (1 {omega}) and 3-ns pulse length and are the 1{omega} fluence-limiting component on NIF. The coatings must have a minimal impact on the beam wavefront and phase to maintain beam focusability, minimize scattered loss, and minimize nonlinear damage mechanisms. This is achieved by specifications ranging from <50 MPa coating stress, <1% coating nonuniformity, <4{angstrom} RMS surface roughness, and a PSD specification to control the amplitude of periodic spatial frequencies. Finally, the primary mission of optical coatings is efficient beam steering so reflection and transmission …

The thermal explosion of trinitrotoluene (TNT) is used as a basis for evaluating the performance of a new One-Dimensional-Time-to-Explosion (ODTX) apparatus. The ODTX experiment involves holding a 12.7 mm-diameter spherical explosive sample under confinement (150 MPa) at a constant elevated temperature until the confining pressure is exceeded by the evolution of gases during chemical decomposition. The resulting time to explosion as a function of temperature provides valuable decomposition kinetic information. A comparative analysis of the measurements obtained from the new unit and an older system is presented. Discussion on selected performance aspects of the new unit will also be presented. The thermal explosion of TNT is highly dependent on the material. Analysis of the time to explosion is complicated by historical and experimental factors such as material variability, sample preparation, temperature measurement and system errors. Many of these factors will be addressed. Finally, a kinetic model using a coupled thermal and heat transport code (chemical TOPAZ) was used to match the experimental data.

This paper reviews our current understanding of the relative advantages of direct drive (DD) and indirect drive (ID) for a 1 GWe inertial fusion energy (IFE) power plant driven by a diode-pumped solid-state laser (DPSSL). This comparison is motivated by a recent study (1) that shows that the projected cost of electricity (COE) for DD is actually about the same as that for ID even though the target gain for DD can be much larger. We can therefore no longer assume that DD is the ultimate targeting scenario for IFE, and must begin a more rigorous comparison of these two drive options. The comparison begun here shows that ID may actually end up being preferred, but the uncertainties are still rather large.

A four-cylinder 1.9 Volkswagen TDI Engine has been converted to run in Homogeneous Charge Compression Ignition (HCCI) mode. The stock configuration is a turbocharged direct injection Diesel engine. The combustion chamber has been modified by discarding the in-cylinder Diesel fuel injectors and replacing them with blank inserts (which contain pressure transducers). The stock pistons contain a reentrant bowl and have been retained for the tests reported here. The intake and exhaust manifolds have also been retained, but the turbocharger has been removed. A heater has been installed upstream of the intake manifold and fuel is added just downstream of this heater. The performance of this engine in naturally aspirated HCCI operation, subject to variable intake temperature and fuel flow rate, has been studied. The engine has been run with propane fuel at a constant speed of 1800 rpm. This work is intended to characterize the HCCI operation of the engine in this configuration that has been minimally modified from the base Diesel engine. The performance (BMEP, IMEP, efficiency, etc) and emissions (THC, CO, NOx) of the engine are presented, as are combustion process results based on heat release analysis of the pressure traces from each cylinder.

The inverse free-electron laser (IFEL) interaction is studied both theoretically and numerically in the case where the drive laser intensity approaches the relativistic regime, and the pulse duration is only a few optical cycles long. We show that by using an ultrashort, ultrahigh-intensity drive laser pulse, the IFEL interaction bandwidth and accelerating gradient are increased considerably, thus yielding large energy gains. Using a chirped pulse and negative dispersion focusing optics allows one to take further advantage of the laser optical bandwidth and produce a chromatic line focus maximizing the gradient. The combination of these novel ideas results in a compact vacuum laser accelerator capable of accelerating picosecond electron bunches with a high gradient (GeV/m) and very low energy spread. A computer code which takes into account the three-dimensional nature of the interaction is currently in development and results are expected this Spring.

Point defects induced in high quality optical-grade based silica by high power (>30 J/cm{sup 2}) 355 nm laser pulses have been investigated to elucidate the nature of laser damage in transparent optics designed for use at the National Ignition Facility (NIF). Six defects have been identified: the NBOHC (non-bridging oxygen hole center), a STE (self-trapped exciton), an ODC (oxygen-deficient center), interstitial oxygen, the E'{sub {gamma}}, and E'{sub 74}. The former four defects were identified and spatially resolved in the damage craters using cathodoluminescence (CL) microanalysis (spectroscopy and microscopy). The latter two defects were identified using ESR spectroscopy at cryogenic temperatures. These defects are unlikely to be a prime factor in damage growth by subsequent laser pulses. Their concentration is too low to effect a high enough temperature rise by a volume absorption mechanism.

Lawrence Livermore National Laboratory (LLNL) has prepared similar flow charts of U.S. energy consumption since 1972. The chart follows the flow of individual fuels and compares these on the basis of a common energy unit of quadrillion British thermal units (Btu). A quadrillion, or ''quad,'' is 10{sup 15}. One Btu is the quantity of heat needed to raise the temperature of 1 pound of water by 1 F at or near 39.2 F. The width of each colored line across this chart is in proportion to the amount of quads conveyed. (Exception: lines showing extremely small amounts have been made wide enough to be clearly visible.) In most cases, the numbers used in this chart have been rounded to the nearest tenth of a quad, although the original data was published in hundredths or thousandths of a quad. As a consequence of independent rounding, some of the summary numbers may not appear to be a precise total of their various components. The first chart in this document uses quadrillion Btu's to conform with data from the U.S. Department of Energy's Energy Information Administration (EIA). However, the second chart is expressed in exajoules. A joule is the metric unit for heat. …

The objective of this study was to examine the relative importance of pressure changes as a source of turbine-passage injury and mortality. Specific tests were designed to quantify the response of fish to rapid pressure changes typical of turbine passage, with and without the complication of the fish being acclimated to gas supersaturated water. We investigated the responses of rainbow trout (Oncorhynchus mykiss), chinook salmon (O. tshawytscha), and bluegill sunfish (Lepomis macrochirus) to these two stresses, both singly and in combination.

People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.

A newly proposed type of multicharged ion source offers the possibility of an economically advantageous high-charge-state fusion driver. Multiphoton absorption in an intense uniform laser focus can give multiple charge states of high purity, simplifying or eliminating the need for charge-state separation downstream. Very large currents (hundreds of amperes) can be extracted from this type of source. Several arrangements are possible. For example, the laser plasma could be tailored for storage in a magnetic bucket, with beam extracted from the bucket. A different approach, described in this report, is direct beam extraction from the expanding laser plasma. They discuss extraction and focusing for the particular case of a 4.1-MV beam of Xe{sup 16+} ions. The maximum duration of the beam pulse is limited by the total charge in the plasma, while the practical pulse length is determined by the range of plasma radii over which good beam optics can be achieved. The extraction electrode contains a solenoid for beam focusing. The design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from the initial model showed that hundreds of amperes could be extracted, but that most of this current missed the solenoid …

Predictions of the properties of nuclides near the extreme limits of nuclear stability provide a measure of our understanding of the fundamental properties of matter and the fission process. Predictions of an ''island of stability'' of long-lived superheavy elements beyond the limits of the known nuclides date back more than 30 years; during this time, there have been many unsuccessful searches for these nuclei. During the last decade, there has been a large effort by our group and others to systematically discover and characterize the properties of the intervening unstable nuclei. Starting 10 years ago, in an on-going collaboration with Russian scientists at the Joint Institute for Nuclear Research (JINR) at Dubna, Russia, we observed the decays of previously unknown isotopes of elements 106, 108, and 110 whose properties are determined by subtleties in the nuclear structure caused by the shell effects that are predicted to result in the island of stability in the still-heavier elements. The resulting data have been successfully reproduced by the theoreticians, whose refined predictions of the decay modes and production rates of the superheavy elements have enabled us to design experiments with the sensitivity to locate these elusive nuclides.

No abstract is available for this document at this time.

This study investigates the inspection of a particular layer of a multi-layer structure using ultrasonic guided waves. Techniques based on Lamb waves have been developed for the inspection of plate structures and are well understood. Guided waves also exist in multi-layered plates as well. Energy distributions vary across the thickness of a multi-layer structure depending on the mode and frequency. Hence, a potential way to inspect the bottom layer of a structure is to find modes with sufficient energy in the bottom layer.

Graphical curves and text tables are presented that map out time and space distortions for data obtained from film records of the Many Beam Fabry Perot Velocimeter. Effective distortion corrections extracted from these mappings can be applied to upcoming velocimetry experiments, but only with limited success over periods of a year or more into the future. A method of using three fiducials to provide fresh time and space distortion data on each film record is presented as a more reliable procedure to correct distortions to an acceptable level of accuracy.

The Drift Scale Test (DST) now underway at Yucca Mountain has been simulated using a Drift Scale Distinct Element (DSDE) model. Simulated deformations show good agreement with field deformation measurements. Results indicate most fracture deformation is located above the crown of the Heated Drift. This work is part of the model validation effort for the DSDE model, which is used to assess thermal-mechanical effects on the hydrology of the rock mass surrounding a potential repository.

There has long been interest in the use of oxygenated hydrocarbon additives to conventional fuels. These oxygenates have been shown to reduce soot emissions in diesel engines and CO emissions in spark-ignition engines; and often allow diesel operation with decreased NO{sub x}. The current widely used additive, MTBE is targeted for elimination as a gasoline additive due to its damaging effects on the environment. This creates a need for alternative oxygenated additives; and more importantly, amplifies the importance to fully understand the thermochemical and kinetic properties on these oxyhydrocarbons fuels and for their intermediate and radical breakdown products. We use CBS-Q and density-functional methods with isodesmic reactions (with group balance when possible) to compute thermodynamic quantities for these species. We have studied hydrocarbons with multiple substituted methoxy groups. In several cases, multioxygenated species are evaluated that may have potential use as new oxygenated fuel additives. Thermodynamic quantities (H{sub 298}{sup 0}, S{sub 298}{sup 0}, C{sub p}(T)) as well as group additivity contributions for the new oxygenated groups are reported. We also report trends in bond-energies with increasing methoxy substitution.

We discuss the no-core shell model approach, an ab initio method with effective Hamiltonians derived from realistic nucleon-nucleon (NN) potentials as a function of the finite harmonic-oscillator (HO) basis space. We present results for three and four nucleon systems in model spaces that include up to 50{Dirac_h}{Omega} and 18{bar h}{Omega} HO excitations, respectively. For these light systems we are in agreement with results obtained by other exact methods. Also, we calculate the properties of {sup 6}Li and {sup 6}He in model spaces up to 10{Dirac_h}{Omega}, and of {sup 12}C for model spaces up to 6{Dirac_h}{Omega}.

A toroidally-asymmetric potential structure in the scrape-off layer (SOL) plasma may be formed by toroidally distributed electrical biasing of the divertor target tiles. The resulting ExB convective motions should increase the plasma radial transport in the SOL and thereby reduce the heat load at the divertor [1]. In this paper we develop theoretical modeling and describe the implementation of this concept to the COMPASS-D divertor. We show that strong magnetic shear near the X-point should cause significant squeezing of the convective cells preventing convection from penetrating above the X-point. This should result in reduced heat load at the divertor target without increasing the radial transport in the portion of the SOL in direct contact with the core plasma, potentially avoiding any confinement degradation. implementation of divertor biasing is in hand on COMPASS-D involving insulation of, and modifications to, the present divertor tiles. Calculations based on measured edge parameters suggest that modest currents {approx} 8 A/tile are required, at up to 150V, to drive the convection. A technical test is preceeding full bias experiments.

Objective--In this paper the photothermal design aspects of novel shape memory polymer (SMP) microactuators for treating stroke are presented. Materials and Methods--A total of three devices will be presented: two interventional ischemic stroke devices (coil and umbrella) and one device for releasing embolic coils (microgripper). The optical properties of SMP, methods for coupling laser light into SMP, heating distributions in the SMP devices and the impact of operating the thermally activated material in a blood vessel are presented. Results--Actuating the devices requires device temperatures in the range of 65 C-85 C. Attaining these temperatures under flow conditions requires critical engineering of the SMP optical properties, optical coupling into the SMP, and device geometries. Conclusion--Laser-activated SMP devices are a unique combination of laser-tissue and biomaterial technologies. Successful deployment of the microactuator requires well-engineered coupling of the light from the diffusing fiber through the blood into the SMP.