The Atmospheric Release Advisory Capability (ARAC) is an operational emergency preparedness and response organization supported primarily by the Departments of Energy and Defense. ARAC can provide real-time assessments of atmospheric releases of radioactive materials at any location in the world. ARAC uses robust three-dimensional atmospheric transport and dispersion models, extensive geophysical and dose-factor databases, meteorological data-acquisition systems, and an experienced staff. Although it was originally conceived and developed as an emergency response and assessment service for nuclear accidents, the ARAC system has been adapted to also simulate non-radiological hazardous releases. For example, in 1991 ARAC responded to three major events: the oil fires in Kuwait, the eruption of Mt. Pinatubo in the Philippines, and the herbicide spill into the upper Sacramento River in California. ARAC`s operational simulation system, includes two three-dimensional finite-difference models: a diagnostic wind-field scheme, and a Lagrangian particle-in-cell transport and dispersion scheme. The meteorological component of ARAC`s real-time response system employs models using real-time data from all available stations near the accident site to generate a wind-field for input to the transport and dispersion model. Here we report on simulation studies of past and potential release sites to show that even in the absence of local meteorological …

Red Teaming is an advanced form of assessment that can be used to identify weaknesses in a variety of cyber systems. it is especially beneficial when the target system is still in development when designers can readily affect improvements. This paper discusses the red team analysis process and the author's experiences applying this process to five selected Information Technology Office (ITO) projects. Some detail of the overall methodology, summary results from the five projects, and lessons learned are contained within this paper.

Laboratory applications for the analysis of PCBs (polychlorinated biphenyls) in environmental matrices such as soil/sediment/sludge and oil/waste oil were evaluated for potential reduction in waste, source reduction, and alternative techniques for final determination. As a consequence, new procedures were studied for solvent substitution, miniaturization of extraction and cleanups, minimization of reagent consumption, reduction of cost per analysis, and reduction of time. These new procedures provide adequate data that meet all the performance requirements for the determination of PCBs. Use of the new procedures reduced costs for all sample preparation techniques. Time and cost were also reduced by combining the new sample preparation procedures with the power of fast gas chromatography. Separation of Aroclor 1254 was achieved in less than 6 min by using DB-1 and SPB-608 columns. With the greatly shortened run times, reproducibility can be tested quickly and consequently with low cost. With performance-based methodology, the applications presented here can be applied now, without waiting for regulatory approval.

The power of the detectors and the datasets at hadronic colliders begins to allow measurement of the electroweak parameters with a precision that confronts the perturbative corrections to the theory. Recent measurements of M{sub z}, M{sub w}, and sin {theta}{sub w} by CDF and UA2 are reviewed, with some emphasis on how experimental precision is achieved, and some discussion of the import for the specifications of the Standard Model. 14 refs., 10 figs., 4 tabs.

Addition of vertex detectors to CDF and D0 will facilitate a rich program of beauty physics at the Tevatron, and may enable tags of B and {tau} which facilitate searches for top and other heavy objects. We also address the operational considerations of triggering and radiation protection, and speculate on possible directions for upgrades. 9 refs., 7 figs.

Beta-iron oxy-hydroxide, which exhibits a (2x2) tunnel-type structure-similar to that of {alpha}-MnO{sub 2}, was found to intercalate reversibly lithium in the tunnels. This material exhibits a potential slightly higher than 2 V with a capacity of 275 mAh/g and very good cyclic reversibility. X-ray Photoelectron Spectroscopy (XPS) investigation of discharged material showed that iron is reduced to the divalent state, and the lithium incorporated in the tunnels was purely ionic. This explains the good reversibility of this electrode material.

In an effort to determine the cesium decontamination factors (DF`s) of the Defense Waste Processing Facility (DWPF) melter off-gas system at the Savannah River Site, the system was verified during an off-gas performance test. The off-gas performance test occurred during the DWPF waste Qualification Campaigns, WP-16 and WP-17. The verification of the off-gas system, which eliminated the need for a startup test involving a radioactive cesium addition, was based on the analysis of nonradioactive cesium across the first and second stage High Efficiency Particulate Air (HEPA) filters. The amount of cesium on the first and second stage HEPA filters was determined by leaching samples from each HEPA filter with nitric acid and analyzing the leachate using Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The ICP-MS method has been demonstrated to be sufficiently sensitive to measure small quantities of cesium on filters. Based on the cesium results of the HEPA filter, cesium DF`s were calculated. The DF`s indicated that the DWPF HEPA filters performed better than the design basis. In addition to the HEPA filters, a determination of the cesium concentration in the melter feed, the canister glass and the off-gas condensate was made. These analyses provided information on cesium flow …

Employing the high resolution of a 5+4 tandem Fabry-Perot interferometer, we discovered that {Delta}{prime}, the Raman active electronic transition between the spin-orbit split 1s(p{sub 3/2}): {Lambda}{sub 8} and 1s(P{sub 1/2}) {Lambda}{sub 7} acceptor ground states, is a doublet for a boron impurity in diamond with a clearly resolved spacing of 0.81 {+-} 0.15 cm{sup {minus}1}. The direct observation of a Stokes/anti-Stokes pair with 0.80 {+-} 0.04 cm{sup {minus}1} shift provides a striking confirmation that the lower 1s(p{sub 3/2}): {Lambda}{sub 8} ground state has experienced a splitting due to a static Jahn-Teller distortion. The Zeeman effect of {Delta}{prime} has been investigated with a magnetic field along several crystallographic directions. Theory of the Zeeman effect, formulated in terms of the symmetry of the substitutional acceptor and the Luttinger parameters of the valence band, allows quantitative predictions of the relative intensities of the Zeeman components in full agreement with experiments. The observation of transitions within the {Lambda}{sub 8} Zeeman multiplet, i.e., the Raman-electron-paramagnetic-resonances, is yet another novel feature to emerge from the present study. The investigation has also yielded g-factors characterizing the Zeeman multiplets.

The Department of Energy (DOE) has as two of its strategic objectives to safely accomplish the world's largest environmental clean-up of contaminated sites and the adoption of the best management practices of the private sector to achieve business-like results efficiently and effectively. An integral part of the strategic response to the challenges facing the Department has been the use of benchmarking and best practice management to facilitate identifying and implementing leading-edge thinking, practices, approaches, and solutions.

Recent space experience has shown that the use of commercial optocouplers can be problematic in spacecraft, such as TOPEX/Poseidon, that must operate in significant radiation environments. Radiation--induced failures of these devices have been observed in space and have been further documented at similar radiation doses in the laboratory. The ubiquitous use of optocouplers in spacecraft systems for a variety of applications, such as electrical isolation, switching and power transfer, is indicative of the need for optocouplers that can withstand the space radiation environment. In addition, the distributed nature of their use implies that it is not particularly desirable to shield optocouplers for use in radiation environments. Thus, it will be important for the space community to have access to radiation hardened/tolerant optocouplers. For many microelectronic and photonic devices, it is difficult to achieve radiation hardness without sacrificing performance. However, in the case of optocouplers, one should be able to achieve both superior radiation hardness and performance for such characteristics as switching speed, current transfer ratio (CTR), minimum power usage and array power transfer, if standard light emitting diodes (LEDs), such as those in the commercial optocouplers mentioned above, are avoided, and VCSELs are employed as the emitter portion of the …

An image-analysis system, based on commercially available data visualization software (IDL [1]), allows convenient interaction with image data while still providing calculated beam parameters at a rate of up to 2 Hz. Image data are transferred from the IOC to the workstation via EPICS [2] channel access. A custom EPICS record was created in order to overcome the channel access limit of 16k bytes per array. The user can conveniently calibrate optical transition radiation (OTR) and fluorescent screens, capture background images, acquire and average a series of images, and specify several other filtering and viewing options. The images can be saved in either IDL format or APS-standard format (SDDS [3]), allowing for rapid postprocessing of image data by numerous other software tools.

A principal goal of the shock physics program at Sandia is to establish a capability to make accurate equation of state (EOS) measurements on the Z pulsed radiation source. The Z accelerator is a source of intense x-ray radiation, which can be used to drive ablative shocks for EOS studies. With this source, ablative multi shocks can be produced to study materials over the range of interest to both weapons and ICF physics programs. In developing the capability to diagnose these types of studies on Z, techniques commonly used in conventional impact generated experimental were implemented. The primary diagnostic presently being used for this work is velocity interferometry, VISAR, which not only provides Hugoniot particle velocity measurements, but also measurements of non-shock EOS measurements, such as isentropic compression. In addition to VISAR capability, methods for measuring shock velocity have also been developed for shock studies on Z. When used in conjunction with the Rankine- Hugoniot jump conditions, material response at high temperatures and pressures can be inferred. Radiation in the Z accelerator is produced when approximately 18 MA are passed through a cylindrical wire array typically 20 to 50 mm in diameter and 10 to 20 mm in height. 200-300 …

We report on the first lasing of a high-gain harmonic generation (HGHG) free-electron laser (FEL). The experiment was conducted at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL). This is a BNL experiment in collaboration with the Advanced Photon Source (APS) at Argonne National Laboratory. A preliminary measurement gives a high-gain harmonic generation (HGHG) pulse energy that is 2 x 10{sup 7} times larger than the spontaneous radiation, In a purely self-amplified spontaneous emission (SASE) mode of operation, the signal was measured as 10 times larger than the spontaneous radiation in the same distance ({approximately}2 m) through the same wiggler. This means the HGHG signal is 2 x 10{sup 6} times larger than the SASE signal. To obtain the same saturated output power by the SASE process, the radiator would have to be 3 times longer (6 m).

Growth kinetics, mechanisms, and material quality in GaN epitaxial lateral over-growth (ELO) were examined using a single mask of systematically varied patterns. A 2-D gas phase reaction/diffusion model describes how transport of the Ga precursor to the growth surface enhances the lateral rate in the early stages of growth. In agreement with SEM studies of truncated growth runs, the model also predicts the dramatic decrease in the lateral rate that occurs as GaN over-growth reduces the exposed area of the mask. At the point of convergence, a step-flow coalescence mechanism is observed to fill in the area between lateral growth-fronts. This alternative growth mode in which a secondary growth of GaN is nucleated along a single convergence line, may be responsible for producing smooth films observed to have uniform cathodoluminescence (CL) when using 1{micro}m nucleation zones. Although emission is comprised of both UV ({approximately}365nm) and yellow ({approximately}550nm) components, the spectra suggest these films have reduced concentrations of threading dislocations normally associated with non-radiative recombination centers and defects known to accompany growth-front convergence lines.

A series of experiments aimed at understanding the influence of the liner interior surface finish on the break-up of shaped charge jets has been completed. The experiments used a standard 81-mm shaped charge design, loaded with LX-14 high explosive; incorporating high-precision copper shaped charged liners. The results indicate that a significant reduction of jet break-up time occurs between a surface finish of 99.30 microinches and 375.65 microinches. Surface finishes of 4.78, 44.54 and 99.30 microinches produced significantly better ductility and associated break-up times than the 375.65-microinch finish. The baseline production process high-precision liners were measured to have an average surface finish of 44.54 microinches. The results show that for the shaped charge warhead geometry and explosive combination investigated, some care must be taken in respect to surface finish, but that very fine surface finishes do not significantly improve the jet ductility and associated break-up times.

A steam generator mock-up has been assembled for round-robin studies of the effectiveness of currently practiced inservice inspection (ISI) technology for detection of current-day flaws. The mock-up will also be used to evaluate emerging inspection technologies. The 3.66-m (12-ft.)-tall mock-up contains 400 tube openings, each consisting of 9 test sections that can be used to simulate current-day field-induced flaws and artifacts. Included in the mock-up are simulations of tube support plate (TSP) intersections and the tube sheet (TS). Cracks are present at the TSP, TS, and in the free span sections of the mock-up. For initial evaluation of the round-robin results, various eddy current methods, as well as multivariate models for data analysis techniques, are being used to estimate the depth and length of defects in the mock-up. To ensure that the round-robin is carried out with procedures as close as possible to those implemented in the field, input was obtained from industry experts on the protocol and procedures to be used for the exercise. One initial assembly of the mock-up with a limited number of flaws and artifact has been completed and tested. A second completed configuration with additional flaw and artifacts simulations will be used for the round-robin.

The performance of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (Bi-2223) superconducting tapes in magnetic fields at 77 K is critical for winding this material into high-field magnets. We have recently enhanced the transport current (I{sub c}) of multifilament Ag-clad Bi-2223 tapes in a self-field at 77 K by increasing the packing density of the precursor powder improving the mechanical deformation, optimizing the conductor design, and adjusting the cooling rate. I{sub c} values of >40 A were obtained repeatedly. However, a transport current of 42 A in a self-field declined to 4 A in a 0.2 T magnetic field applied parallel to the c-axis at 77 K. A new composite tape was then fabricated in which a YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (Y-123) film was deposited on the top of the Ag-sheathed Bi-2223 tape to shield the applied magnetic field and protect the central Bi-2223 filaments. Magnetization measurements showed that the critical current densities of the Y-123-coated, Ag-sheathed Bi-2223 tapes were higher than those of an uncoated tape. These preliminary results may provide the basis for further improving the processing of long-length Bi-2223 tapes for high-field applications.

Recent improvements in the Super Transition Array (STA) method for calculating Bound-Bound (BB) and Bound-Free (BF) emission and absorption spectra for LTE plasma are described and illustrated. The method accounts for all possible BB and BF radiative transitions in the plasma. Full detailed first order quantum relativistic treatment is used for calculating transition energies and probabilities. The enormous number of configurations are divided into sets of superconfigurations comprised of a collection of energetically grouped configurations. The contribution of the transition array between two superconfigurations to a specific one-electron transition is then represented by a Gaussian whose moments are calculated accurately using a technique that bypasses the necessity of direct summation over all the levels involved. The calculation of these moments involves the populations of the configurations given by their statistical weights and the Boltzmann factor. For each configuration within the super configuration we use zeroeth order energies in the Boltzmann factor corrected by a super configuration averaged first order term. The structure of the spectrum is increasingly revealed by splitting each STA into a number of smaller STAs. When the spectrum converges it describes the detailed UTA' structure, where each configuration-to-configuration array is represented by a separate Gaussian with first …

The electronic defect density of native, anodic, and synthetic Al oxide layers on Al were studied by solid state electrical measurement as a function of hydration OF the oxide. The non-hydrated synthetic Al oxide layers, which included electron cyclotron resonance (ECR) plasma deposited oxides as well as ECR plasma grown oxides, were highly insulating with electrical transport dominated by thermal emission from deep traps within the oxide. Following hydration these oxides and the native oxides exhibited a large increase in electronic defect density as evidenced by increases in the DC leakage current, reduction in the breakdown field, and increase in AC conductance. Elastic recoil detection of hydrogen revealed that hydration leads to hydrogen incorporation in the oxide films and hydrogen injection through the films into the Al layer below. The increase in electronic defect concentration is related to this hydrogenation and may play a significant role in localized corrosion initiation.

A fast-running time-dependent one-dimensional particle code has been developed to simulate transients in both electrostatic quadrupole and electrostatic column heavy-ion injectors. Two-dimensional effects are incorporated through the use of an approximation to the transverse part of the Laplacian operator. Longitudinal electric fields are solved on a mesh. An external circuit is coupled to the column, and the effect of the beam on the circuit is modeled. Transients such as initial current spikes, space-charge de-bunching, and beam loading of the circuit, are simulated. Future directions for the code include introduction of envelope and centroid equations to provide beam radius and displacement information and the modeling of secondary electron currents arising from beam-spill.

The Intermediate Silicon Layers (ISL) detector is being built as part of the Collider Detector at Fermilab (CDF) upgrades for the run II operation of Tevatron. The ISL Space Frame (SF) is a structure that defines the location of the ISL detectors, supports the micro-vertex silicon trackers (SVXII, L00) as well as the beryllium beam pipe. The SF design, project and construction is challenging due to the precision and mechanical stability requirements that must be achieved using a minimum amount of material. The SF is a high precision light structure made in carbon fiber designed and built at the INFN Pisa and shipped at Fermilab in summer 1999. In this contribution we describe in detail the SF construction phase and the accuracy obtained.

An understanding of the state of stress on faults is important for pre- and postclosure performance considerations for the potential high-level radioactive waste repository at Yucca Mountain. This paper presents the results of three-dimensional numerical analyses that provide estimates of the state of stress through time (10,000 years) along three major faults in the vicinity of the potential repository due to thermal stresses resulting from waste emplacement. It was found, that the safety factor for slip close to the potential repository increases with time after waste emplacement. Possible fault slip is predicted above and below the potential repository for certain loading conditions and times. In general, thermal loading reduces the potential for slip in the vicinity of the potential repository.

Many lessons have been learned over the past 24 years as the Waste Isolation Pilot Plant (WIPP) project has progressed from initial site characterization to final licensing that may be of relevance to other nuclear-waste-disposal projects. These lessons pertain to the manner in which field and laboratory investigations are planned, how experiments are interpreted, how conceptual and numerical models are developed and simplified~ and how defensibility and credibility are achieved and maintained. These lessons include 1) Site characterization and performance assessment (PA) should evolve together through an iterative process, with neither activity completely dominating the other. 2) Defensibility and credibility require a much greater depth of understanding than can be represented in PA models. 3) Experimentalists should be directly involved in model and parameter abstraction and simplification for PA. 4) External expert review should be incorporated at all stages of a project~ not just after an experiment or modeling activity is completed. 5) Key individuals should be retained for the life of a project or a process must be established to transfer their working knowledge to new individuals. 6) An effective QA program needs to be stable and consistent for the duration of a project and rests on best scientific …

Most analytical solutions and computer codes for well-test analysis assume a radial flow geometry around a well even though actual flow geometries can be quite different particularly in fractured media. Accurate estimation of hydraulic parameters requires knowledge of the flow geometry. Flow dimensions, representing the combined effects of flow geometry and variations in hydraulic properties, em be interpreted from the late-time slope of the pressure derivative on a log-log plot. However, the interpreted flow dimensions could be caused by an infinite number of flow geometry and hydraulic property combinations. Identifying the correct flow geometry so that appropriate hydraulic properties can be calculated is a difficult process, requiring additional information from a variety of sources. Defining a "conservative" model for a system with nonradial flow dimensions is problematic at best. Errors are compounded when hydraulic properties interpreted by force-fitting radial model to tests in nonradial systems are used in flow and transport models that also fail to take proper account of flow geometry. Whatever the flow dimension of a system might be, proper test interpretation and careful model construction, calibration, and testing are required to provide accurate modeling of flow and transport in that system.