Suprathermal electrons are diagnosed by a hard x-ray pinhole camera during lower hybrid current drive on PBX-M. The experimental hard x-ray images are compared with simulated images, which result from an integration of the relativistic bremsstrahlung along lines-of-sight through the bean-shaped plasma. Images with centrally peaked and radially hollow radiation profiles are easily distinguished. The energy distribution of the suprathermal electrons is analyzed by comparing images taken with different absorber foils. An effective photon temperature is derived from the experimental images, and a comparison with simulated photon temperatures yields the energy of the suprathermal electrons. The analysis indicates that the energy of the suprathermal electrons in the hollow discharges is in the 50 to 100 key range in the center of the discharge. There seems to exist a very small higher energy component close to the plasma edge.

Construction of the Continuous Electron Beam Accelerator Facility recirculating linac represents the largest scale application of superconducting rf (SRF) technology to date. Over 250 of the eventual 338 SRF 1497 MHz cavities have been assembled into hermetic pairs and completed rf testing at 2.0 K. Although the rf performance characteristics well exceed the CEBAF baseline requirements of Q[sub 0] = 2.4[times]10[sup 9] at 5 MV/m, the usual limiting phenomena are encountered field emission, quenching, Q-switching, will occasional multipacting. An analysis of the occurrence conditions and severity of these phenomena during production cavity testing is presented. The frequency with which performance is limited by quenching suggests that additional material advances may be required for applications which require the reliable achievement of accelerating gradients of more than 15 MV/m. The distributions of frequency and Q for a higher-order mode are also presented.

A Macro Material Flow Modeling (MMFM) concept and approach are being adopted to develop a predictive modeling capability. This capability is intended to provide part of the basis for evaluating potential impacts from various solid waste management system configurations and operating scenarios, as well as evaluating the impacts of various policies on solid waste quantities and compositions. The MMFM capability, as part of a broader Solid Waste Initiative at Pacific Northwest Laboratory, is intended to provide an increased understanding of solid waste as a disposal, energy, and resource problem on a national and global scale, particularly over the long term. This model is a macro-level simulation of the flows of the various materials through the solid waste management system, and also through the associated materials production and use system. Inclusion of materials production and use within the modeling context allows a systems approach to be used, providing a much more complete understanding of the origins of the solid waste materials and also of possible options for materials recovery and reuse than if a more traditional end-of-pipe'' view of solid waste is adopted. The MMFM is expected to be useful in evaluating longer-term, broader-ranging solid waste impacts than are traditionally evaluated …

Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to determine the structural environment local to iron(HI) and zircorium(IV) cations in respectively, nanoscale iron oxyhydroxide and nanoscale zirconium oxide powders. The iron oxyhydroxide powder, produced by the modified reverse micelle (MRM) technology, was found to have a short-range structure most similar to that of goethite ([alpha]-FeOOH). The short-range structure of the zirconium oxide powder, produced using the rapid thermal decomposition of solutes (RTDS) technology, was found to be a mixture of monoclinic zirconia and cubic zirconia environments.

When fcc metals and alloys are irradiated at elevated temperatures, they tend to evolve toward saturation microstructures that are independent of the starting state of the metal and the early details of irradiation history. This leads to property changes and rates of dimensional change that also eventually become independent of the starting state. The evolution of microstructure in complex alloys, especially during the transient regime, is usually determined by the complex interaction of many microstructural and microchemical processes. The more complex the alloy, the more difficult it is to-identify and define the separate influence of each participating mechanism. The use of irradiation studies conducted on simple metals or model alloys assists in understanding the behavior of alloys of engineering relevance. A review of such studies shows that a number of prevailing perceptions of radiation-induced microstructural evolution are not universally correct.

These notes give an overview of some aspects of the quantum theory of light and its interaction with matter. A description is given of basic emission and absorption processes, as well as the theory of photodetection and optical coherence. Basic research in this area is increasingly relevant to areas of technological importance, including microlaser devices and the noise characteristics of semiconductor lasers.

Linac beams in the Stanford Linear Collider (SLC) were driven into oscillation by transverse vibration of lattice quadrupoles at about 7 Hz. These quadrupoles are centered on 12-meter support girders located early in the linac. The vibrations were caused by ground motion at the 0.06 {mu}m level which was amplified in the accelerator supports up to 5 {mu}m. Seismic and support vibration measurements were Fourier analyzed and a strong correlation with beam observations was observed. Subsequent modifications of the supports have eliminated these oscillations.

As part of the Southern Oxidant Study (SOS) (UCAR, 1990), Brookhaven National Laboratory operated a ``SENIOR`` (South Eastern Network for Intensive Ozone Research) measurement site on a campaign basis during parts of the summers of 1991 and 1992. Measurements were made for the purpose of understanding the pervasive high levels of O{sub 3} observed in the southeastern US (Meagher et al, 1987 Aneja et al, 1990; NRC, 1991). In this article the authors focus on the 1992 observations of O{sub 3} and the predication of O{sub 3} formation rates based on a radical budget calculation and based on the photostationary state.

The Stanford Linear Collider (SLC) was recently converted to flat beam operation ({gamma}{epsilon}{sub x} = 10 {gamma}{epsilon}{sub y}), producing a factor of two increase in luminosity. In this paper we review the results of flat beam studies in the SLC Linac. In summary, the injected beams from the damping rings had invariant horizontal emittances as low as 30 mm-mrad and invariant vertical emittances as low as 2 mm-mrad. The emittances measured at the end of the linac after tuning for 3 {times} 10{sup 10} particles are about 5 to 8 mm-mrad vertically and 40 to 50 mm-mrad horizontally. Flat beam operation began 3/17/93.

We report here a relatively large increase in emission of the integrated 800 nm line when pumping the UV absorption and a much smaller increase (by a factor of {approximately}15) upon pumping the IR absorption band in solid D-T at 4.6 K. These data show the 800 run emission is most likely the result of an electron bubble transition. We also present ESR data for electrons in D{sub 2} and H{sub 2} doped with 2% T{sub 2} and pure T{sub 2}. We find there are two components to this absorption, a narrow line component which we attribute to trapped electrons and a broad line component which we attribute to delocalized electrons. The narrow ESR linewidth in the H{sub 2} and D{sub 2} samples are commensurate with the idea of electrons localized in vacancy seeded traps. In solid T{sub 2 } the broad line dominates, implying that most electrons are delocalized due to the large concentration of electrons and other impurities. We find that the temperature and time dependence of the electron concentration from the 800 nm line is similar to the unpaired atoms as measured previously with ESR.

Aging risk evaluations of nuclear power plants using Probabilistic Risk Analyses (PRAs) involve assessments of the impact of aging structures, systems, and components (SSCs) on plant core damage frequency (CDF). These assessments can be used to prioritize the aging risk contributors reflecting the relative risk potential of the SSCs. Aging prioritization are important for identification of SSCs most contributing to plant risk and can provide a systematic basis on which aging risk control and management strategies for a plant can be developed. These prioritizations are, however, subject to variabilities arising from uncertainties in data and/or from various modeling assumptions. The objective of this paper is to present an evaluation of the sensitivity of aging prioritizations of active components to uncertainties in aging risk quantifications. Approaches for robust prioritization of SSCs are also presented which are less susceptible to the uncertainties.

The overall objective of this project was to determine the state-of-the-art and to what extent existing SMES is a viable option in meeting the needs of utilities and their customers for improving electric service power quality. By defining and analyzing SMES electrical/mechanical performance characteristics, and comparing SMES application benefits with competitive stored energy systems, industry will be able to determine SMES unique applications and potential market penetration. Building on this information base, it would also be possible to evaluate the impact of high temperature superconductors (77 K and 20-35 K) on SMES technology applications. The authors of this report constructed a network of industry contacts and research consultants that were used to collect, update, and analyze ongoing SMES R&D and marketing activities in industries, utilities, and equipment manufacturers. These key resources were utilized to assemble performance characteristics on existing SMES, battery, capacitor, flywheel, and high temperature superconductor (HTS) stored energy technologies. From this information, preliminary stored energy system comparisons were accomplished. In this way, the electric load needs would be readily comparable to the potential solutions and applications offered by each aforementioned energy storage technology.

In the SSC design the 87.12 km long collider lattice consists of two 35.28 km identical arcs located on the North and South sides of the machine and two 8.28 km clusters placed on the West and on the East. Each cluster contains two Interaction Regions (IRs), the Utility section and the interconnect sections between them. According to present plans the goal for the optics in the East IRs is to provide for a high value of the luminosity and, hence, for a low {beta} at the Interaction Point (IP). The West IRs are aimed at providing for a large space for detector which can be achieved at the cost of higher value of the {beta} and lower luminosity. The optics of each IR are based on the same optical configuration which gives an opportunity to use mostly identical quadrupoles and dipoles in four IRs. Trivial modification of the central region in this basic configuration allows for a wide range of values for detector free space from L = 20 m to L = 90 m, suitable for the experiments in both clusters. L denotes here the distance between the IP and the nearest magnetic element of the machine. In …

A brief review of Monte Carlo event generators for simulating hadron-hadron collisions is presented. Particular emphasis is placed on comparisons of the approaches used to describe physics elements and identifying their relative merits and weaknesses. This review summarizes a more detailed report.

The b{bar b} production cross section is estimated to be 1 mb at {radical}s = 40 TeV, implying 10{sup 12} produced b{bar b} pairs at an SSC luminosity of 10{sup 32}cm{sup {minus}2}sec{sup {minus}1} (.1 {times} design). SDC has the potential to exploit this high rate to explore a-number of B physics topics, in particular, CP violation in the neutral B meson. This note describes the SDC particle tracking design and its predicted performance parameters relevant to B physics.

Experimental tests of a ``second bunch length compressor`` in a linac is important for the next generation of linear colliders and for other future accelerators. These future accelerators need bunches with lengths of order 0.06 {minus} 0.2 mm. At these lengths, new accelerator dynamics will be encountered. We have studied the possibility of constructing a second compressor with the present SLAC linac and have found a reasonable design. The core of this project is to reconfigure an old beamline (BL-90) at the 1000m location in the linac to: (1) extract a 10 GeV bunch, (2) pass it through a new 96 m long transport line in which length compression is done, and (3) reinject the beam into the main linac in an available drift section. Using the resulting compressed bunch, accelerator physics tests would be performed in the remaining downstream linac with the resulting very high charge density. The bunch compression in this transport line results from the TRANSPORT element R{sub 56} as determined from the optics of the transport line. {Delta}z = R{sub 56} {Delta}E/E. For example, if {Delta}z = {minus}0.5 mm, {Delta}E/E = 0.5%, R{sub 56} = {minus}0.1 m, a bunch of 5 {times} 10{sup 10} particles would …

Pinta is a system for segmentation and visualization of anatomical structures obtained from serial sections reconstructed from Magnetic Resonance Imaging. The system approaches the segmentation problem by assigning each volumetric region to an anatomical structure. This is accomplished by satisfying constraints at the pixel level, slice level, and volumetric level. Each slice is represented by an attributed graph, where nodes correspond to regions and links correspond to the relations between regions. These regions are obtained by grouping pixels based on similarity and proximity. The slice level attributed graphs are then coerced to form a volumetric attributed graph, where volumetric consistency can be verified. The main novelty of our approach is in the use of the volumetric graph to ensure consistency from symbolic representations obtained from individual slices. In this fashion, the system allows errors to be made at the slice level, yet removes them when the volumetric consistency cannot be verified. Once the segmentation is complete, the 3D surfaces of the brain can be constructed and visualized.

The equation of state (EOS) of astrophysical plasmas is, for a wide range of stars, nearly ideal; with only small non-ideal Coulomb corrections. Calculating the EOS of an ionizing plasma from a ground state ion, ideal gas model is easy, whereas, fundamental methods to include the small Coulomb corrections are difficult. Attempts to include excited bound states are also complicated by plasma screening and microfield phenomena that weaken and broaden these states. Nevertheless, the high quality of current observational data, particularly seismic, dictates that the best possible models should be used. The present article discusses these issues and describes how they are resolved by fundamental many-body quantum statistical methods. Particular emphasis is placed on the activity expansion method that is the basis of the OPAL opacity code. Some comparisons with standard methods are given.

Synchrotron motion was induced by phase shifting the rf of the Indiana University Cyclotron Facility (IUCF) cooler-synchrotron. The resulting coherent-bunch motion was tracked in longitudinal phase space for as many as 700,000 turns, or for over 350 synchrotron oscillations. Results of recent experimental studies of longitudinal motion in which the rf phase and amplitude were harmonically modulated are also presented. Comparisons of experimental data with numerical simulations, assuming independent particle motion, are made. Observed multiparticle effects are also discussed.

The betatron difference resonance, Q{sub z} {minus} 2Q{sub z} = {minus}6, where Q{sub x,z} are the number of betatron oscillations per turn, was studied at the Indiana University Cyclotron Facility (IUCF) cooler ring. The position of the beam was measured in both the horizontal and vertical planes of oscillation after a pulsed kicker magnet was fired to produce coherent motion. The effect of the coupling resonance was clearly observed and it was found that the subsequent particle motion could be described by a simple Hamiltonian. The resonance strength and tune shift as a function of betatron amplitude were measured.

The experimental observations of motion near the betatron sum resonance, {nu}{sub x} + 2{nu}{sub z} = 13, are presented. A fast quadrupole (Panofsky-style ferrite picture-frame magnet with a pulsed power supplier) producing a betatron tune shift of the order of 0.03 at rise time of 1 {mu}s was used. This quadrupole was used to produce betatron tunes which jumped past and then crossed back through a betatron sum resonance line. The beam response as function of initial betatron amplitudes were recorded turn by turn. The correlated growth of the action variables, J{sub x} and J{sub z}, was observed. The phase space plots in the resonance frame reveal the features of particle motion near the nonlinear sum resonance region.

One method of increasing the intensity of the LAMPF proton Storage Ring is to use a brighter H{sup {minus}} ion source. To develop such a source, the performance of the small LBL dipole filter and the BNL toroidal filter volume H{sup {minus}} sources are being investigated. Results of testing a new high-duty-factor design of the BNL toroidal filter volume source are discussed. Results of experiments to reduce the electron to H{sup {minus}} ratio and modulate the beam intensity in the small LBL source are presented.

An empirical correlation between the fissile mass and the leakage multiplication factor, as determined by High Level Neutron Coincidence (HLNC) counting, was developed based on available measurement data. This correlation has been used successfully for the simulation of HLNC counting. With the singles count rate (totals), the correlation can be used to obtain a quick estimate of the plutonium mass of the sample in less time than required to measure the real coincidence count rate. The correlation can also be used to evaluate samples contaminated with ({alpha},n) sources such as fluorine.

Abstracts are presented from a meeting on landscape ecology. Topics include: conservation, climatic change, forest management, aquatic, wetland, rural and urban landscapes, land use, and biodiversity.