A letter report issued by the General Accounting Office with an abstract that begins "In the National Defense Authorization Act for Fiscal Year 2003, Congress authorized the Secretary of Defense to provide administrative services and support to foreign coalition liaison officers temporarily assigned to the headquarters of a combatant command or any of its subordinate commands. Congress required GAO to assess the implementation of this legislation. Specifically, GAO's objectives were to determine (1) what guidance the Department of Defense (DOD) has provided on the implementation of this legislation, (2) the extent to which the commands are aware of and are using this legislation, and (3) the level of support being provided by commands using this legislation and the benefits derived from it."

Under the sponsorship of the U.S. DOE and DHS, we have developed a CFD model for simulating flow and dispersion of chemical and biological agents released in the urban environment. Our model, FEM3MP (Chan and Stevens, 2000), is based on solving the three-dimensional, time-dependent, incompressible Navier-Stokes equations on massively parallel computer platforms. The model uses the finite element method for accurate representation of complex building shapes and variable terrain, together with a semi-implicit projection method and modern iterative solvers for efficient time integration (Gresho and Chan, 1998). Physical processes treated include turbulence modeling via the RANS (Reynolds Averaged Navier-Stokes) and LES (Large Eddy Simulation) approaches, atmospheric stability, aerosols, UV radiation decay, surface energy budget, and vegetative canopies, etc. Predictions from our model are continuously being verified and validated against data from wind tunnel (Chan and Stevens, 2000; Chan, et al., 2001) and field experiments (Chan, et al., 2002, 2003; Lee, et al., 2002; Humphreys, et al., 2003; and Calhoun, et al., 2004). Discussed below are several examples to illustrate the use of FEM3MP in simulating flow and dispersion in urban areas and forest canopies, with model results compared against available field measurements.

In this paper we present a method for the spatial analysis of complex cellular systems based on a multiscale study of neighborhood relationships. A function to measure those relationships, M, is introduced. The refined Relative Neighborhood Graph is then presented as a method to establish vicinity relationships within layered cellular structures, and particularized to epithelial cell nuclei in the mammary gland. Finally, the method is illustrated with two examples that show interactions within one population of epithelial cells and between two different populations.

Among the many physics processes at TeV hadron colliders, we look most eagerly for those that display signs of the Higgs boson or of new physics. We do so however amid an abundance of processes that proceed via Standard Model (SM) and in particular Quantum Chromodynamics (QCD) interactions, and that are interesting in their own right. Good knowledge of these processes is required to help us distinguish the new from the known. Their theoretical and experimental study teaches us at the same time more about QCD/SM dynamics, and thereby enables us to further improve such distinctions. This is important because it is becoming increasingly clear that the success of finding and exploring Higgs boson physics or other New Physics at the Tevatron and LHC will depend significantly on precise understanding of QCD/SM effects for many observables. To improve predictions and deepen the study of QCD/SM signals and backgrounds was therefore the ambition for our QCD/SM working group at this Les Houches workshop. Members of the working group made significant progress towards this on a number of fronts. A variety of tools were further developed, from methods to perform higher order perturbative calculations or various types of resummation, to improvements in …

The elimination of in-board ohmic heating solenoid is required for the spherical torus (ST) to function as an attractive fusion power plant. An in-board ohmic solenoid, along with the shielding needed for its insulation, increases the size and, hence, the cost of the plant. Here, we investigate using static as well as dynamic codes in ST geometries a solenoid-free start-up concept utilizing a set of out-board poloidal field coils. By using the static code, an optimization of coil positions as well as coil currents was performed to demonstrate that it is indeed possible to create a high quality multi-pole field null region while retaining significant flux (volt-seconds) needed for the subsequent current ramp-up. With the dynamic code that includes the effect of vacuum vessel eddy currents, we then showed that it is possible to maintain a large size field null region for several milliseconds in which sufficient ionization avalanche can develop in the applied toroidal electric field. Under the magnetic geometry typical of a next generation spherical torus experiment, it is shown that the well-known plasma breakdown conditions for conventional ohmic solenoid start-up of E(sub)TB(sub)T/B(sub)P {approx} (0.1-1) kV/m with V(sub)loop {approx} 6 V can be readily met while retaining significant …

Properties of the multi-species electromagnetic Weibel and electrostatic two-stream instabilities are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters.

Understanding the transition-crossing process is crucial for improving Booster performance at high intensity. The synchronous phase appears to drop toward 90{sup o} right after transition regardless of beam intensity, more so at higher beam intensity. The implication is that the effective rf voltage (RFSUM) will run into a limit right after transition when the synchronous phase reaches 90{sup o} for high intensity beam. A reduction in RFSUM is also observed at the same time. Solutions, such as raising the rf voltage during the transition period or controlling the RFSUM reduction by increasing longitudinal emittance before transition, are potentially important for high intensity operation.

To achieve high focal spot intensities in heavy ion fusion, the ion beam must be compressed longitudinally by factors of ten to one hundred before it is focused onto the target. The longitudinal compression is achieved by imposing an initial velocity profile tilt on the drifting beam. In this paper, the problem of longitudinal drift compression of intense charged particle beams is solved analytically for the two important cases corresponding to a cold beam, and a pressure-dominated beam, using a one-dimensional warm-fluid model describing the longitudinal beam dynamics.

We examine the effect of the collective force due to coherent synchrotron radiation (CSR) in an electron storage ring with small bending radius. In a computation based on time-domain integration of the nonlinear Vlasov equation, we find the threshold current for a longitudinal microwave instability induced by CSR alone. The model accounts for suppression of radiation at long wave lengths due to shielding by the vacuum chamber. In a calculation just above threshold, small ripples in the charge distribution build up over a fraction of a synchrotron period, but then die out to yield a relatively smooth but altered distribution with eventual oscillations in bunch length. The instability evolves from small noise on an initial smooth bunch of r.m.s.length much greater than the shielding cutoff. The paper includes a derivation and extensive analysis of the complete impedance function Z for synchrotron radiation with parallel plate shielding. We find corrections to the lowest approximation to the coherent force which involve ''off-diagonal'' values of Z, that is, fields with phase velocity not equal to the particle velocity.

Calculational assessment and experimental verification of certain neutron cross sections that are related to widely needed new medical isotopes. Experiments were performed at the Oregon State University TRIGA Reactor and the High Flux Irradiation Reactor at Oak Ridge National Laboratory.

High-speed micro-strip micro-channel plate (MCP) x-ray framing cameras are a well established diagnostic for laser plasma experiments. Each frame acquired with these devices requires a separate image, and with most reasonable x-ray optics, a separate line of sight, causing potential parallax problems. Gated image tubes have a single line of sight capability, but the conventional designs have not been effectively extended to the short gating times of the micro-strip-line MCP camera. A hybrid camera combining image tube and micro-strip-line MCP technology has been under development at LLNL in collaboration with UR/LLE, and KENTECH Instruments. The key feature of this single line of sight (SLOS) hybrid image tube is a deflection assembly that continuously divides the electrons from a single photocathode x-ray image into a set of four electron images. Temporal gating of these images is carried out using a microstripline microchannel plate framing camera module positioned at the image plane of the electron tube. Characterization measurements performed using both X-rays from a Manson source and from laser generated plasmas, will be presented. Some implementation improvements will be discussed. The results will be compared to simulations carried out using the charged particle optics code SIMION. Various dissector designs were simulated in …

The soft x-ray microstripline microchannel plate (MCP) framing camera has become one of the workhorses of ICF diagnostics. Much progress has been made in making these diagnostics work well with gate times of 100 ps and below. Often weak input signal or source timing uncertainties dictate a requirement for longer gate times, preferably in the same instrument that also has fast gating capability. The large power-law dependence of MCP gain on applied voltage is useful in shortening the gating time of the microstripline camera. However, this sensitivity leads to tight constraints on the shape of the long duration electrical pulses that are needed to drive the MCP to produce experimentally desirable optical gating profiles. Simple modeling and measurements are used to better understand the character of the voltage pulses needed to achieve optical gate widths between 500 ps and {approx}2 ns.

We have measured the production of hv {approx} 4.7 keV x-rays from low-density Ti-doped aerogel ({rho} {approx} 3 mg/cc) targets at the OMEGA laser facility (University of Rochester), with the goal of maximizing x-ray output. Forty OMEGA beams ({lambda}{sub L} = 0.351 {micro}m) illuminated the two cylindrical faces of the target with a total power that ranged from 7 to 14 TW. The laser fully ionizes the target (n{sub e}/n{sub crit} {le} 0.1), and a laser-bleaching wave excites, supersonically, the high-Z emitter ions in the sample. Heating in the target was imaged with gated x-ray framing cameras and an x-ray streak camera. Ti K-shell x-ray emission was spectrally resolved with a two-channel crystal spectrometer and also with a set of filtered aluminum x-ray diodes, both instruments provide absolute measurement of the multi-keV x-ray emission. We find between 40 - 260 J of output with 4.67 {le} hv {le} 5.0 keV. Radiation-hydrodynamic calculations predict late time enhancement of the x-ray power due first to axial stagnation of the heating waves, then, ablatively-driven radial compression from the target walls.

We examine various options for calibration of NIF neutron detectors in the energy region E<14 MeV. These options include: downscatter of D-T fusion neutrons using plastic targets; nuclear reactions at a Tandem Van de Graaf accelerator; and ''white'' neutrons from a pulsed spallation source. As an example of the spallation option, we present some calibration data that was recently obtained with a single crystal CVD diamond detector at the Weapons Neutron Research facility (WNR) at LANL.

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Dissolution rates for spent fuel have typically been reported in terms of a rate normalized to the surface area of the specimen. Recent evidence has shown that neither the geometric surface area nor that measured with BET accurately predicts the effective surface area of spent fuel. Dissolution rates calculated from results obtained by flowthrough tests were reexamined comparing the cumulative releases and surface area normalized rates. While initial surface area is important for comparison of different rates, it appears that normalizing to the surface area introduces unnecessary uncertainty compared to using cumulative or fractional release rates. Discrepancies in past data analyses are mitigated using this alternative method.

We present first principles, computational predictions of a porous, nano-structured semiconductor material that will reversibly store hydrogen for fuel cell applications. The material is competitive with current metal hydride storage materials, but contains only carbon and silicon, reducing both its cost and environmental impact. Additionally, unlike metal hydrides, the core skeleton structure of this material is unaltered when cycling from full hydrogen storage to full hydrogen depletion, removing engineering complications associated with expansion/contraction of the material.

Medium carbon steel (MCS) is the candidate material for rock bolts to reinforce the borehole liners and emplacement drifts of the proposed Yucca Mountain (YM) high-level nuclear waste repository. Corrosion performance of this structural steel -AISI 1040- was investigated by techniques such as linear polarization, electrochemical impedance spectroscopy (EIS), and laboratory immersion tests in lab simulated concentrated YM ground waters. Corrosion rates of the steel were determined for the temperatures in the range from 25 C to 85 C, for the ionic concentrations of 1 time (1x), 10 times (10x), and hundred times (100x) ground waters. The MCS corroded uniformly at the penetration rates of 35-200 {micro}m/year in the de-aerated YM waters, and 200-1000 {micro}m/year in the aerated waters. Increasing temperatures in the de-aerated waters increased the corrosion rates of the steel. However, increasing ionic concentrations influenced the corrosion rates only slightly. In the aerated 1x and 10x waters, increasing temperatures increased the rates of MCS significantly. Inhibitive precipitates, which formed in the aerated 100x waters at higher temperatures (65 C and up) decreased the corrosion rates to the values that obtained for the de-aerated YM aqueous environments. The steel suffered pitting corrosion in the both de-aerated and aerated hot …

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The Defense Threat Reduction Agency, DTRA, is a federal agency charged with safeguarding the nation from weapons of mass destruction, in particular nuclear weapons such as crude devices, and radiological dispersal devices (RDD), also known as dirty bombs. Both of which could be delivered using unconventional means such as by transporting them by a car or boat. Two years ago DTRA partnered with NNSA to evaluate commercially available technologies that could be deployed quickly to defend against threats posed by unconventional nuclear weapons under a program called the Unconventional Nuclear Warfare Defense (UNWD) Program. Lawrence Livermore National Laboratory (LLNL) was one of several National laboratories that participated in this program, which consisted in developing, deploying, and demonstrating detection systems suitable for military base protection. Two key contributions to this program by the LLNL team were the development of two Radiation Detection Buoys (RDB) deployed at Naval Base in Kings Bay in Georgia, and the Detection and Tracking System (DTS) demonstrated at Fort Leonard Wood Missouri, headquarters for the Total Force's Maneuver Support Center (MANSCEN). The RDB's were designed to detect the potential transportation of an unconventional nuclear or radiological weapon by a boat. The RDB's consisted of two commercial marine …

Our ability to simulate physical processes numerically is constrained by our ability to solve the resulting linear systems, prompting substantial research into the development of multiscale iterative methods capable of solving these linear systems with an optimal amount of effort. Overcoming the limitations of geometric multigrid methods to simple geometries and differential equations, algebraic multigrid methods construct the multigrid hierarchy based only on the given matrix. While this allows for efficient black-box solution of the linear systems associated with discretizations of many elliptic differential equations, it also results in a lack of robustness due to assumptions made on the near-null spaces of these matrices. This paper introduces an extension to algebraic multigrid methods that removes the need to make such assumptions by utilizing an adaptive process. The principles which guide the adaptivity are highlighted, as well as their application to algebraic multigrid solution of certain symmetric positive-definite linear systems.

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.

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