The Heavy Ion Fusion Virtual National Laboratory is developing the intense ion beams needed to drive matter to the High Energy Density regimes required for Inertial Fusion Energy and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final focus experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line Ion Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments.

We review several proposals for generation of solitary attosecond pulses using two types of free electron lasers which are envisioned as future light sources for studies of ultra-fast dynamics using soft and hard x-rays.

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Those working with alternating-gradient (A-G) systems look for simple, accurate ways to analyze A-G performance for matched beams. The useful K-V equations are easily solved in the smooth approximation. This approximate solution becomes quite inaccurate for applications with large focusing fields and phase advances. Results of efforts to improve the accuracy have tended to be indirect or complex. Their generalizations presented previously gave better accuracy in a simple explicit format. However, the method used to derive their results (expansion in powers of a small parameter) was complex and hard to follow; also, reference 7 only gave low-order correction formulas. The present paper uses a straightforward iteration method and obtains equations of higher order than shown in their previous paper.

Matlab is an interpretive programming language originally developed for convenient use with the LINPACK and EISPACK libraries. Matlab is appealing for accelerator physics because it is matrix-oriented, provides an active workspace for system variables, powerful graphics capabilities, built-in math libraries, and platform independence. A number of accelerator software toolboxes have been written in Matlab -- the Accelerator Toolbox (AT) for model-based machine simulations, LOCO for on-line model calibration, and Matlab Channel Access (MCA) to connect with EPICS. The function of the MATLAB ''MiddleLayer'' is to provide a scripting language for machine simulations and on-line control, including non-EPICS based control systems. The MiddleLayer has simplified and streamlined development of high-level applications including configuration control, energy ramp, orbit correction, photon beam steering, ID compensation, beam-based alignment, tune correction and response matrix measurement. The database-driven Middle Layer software is largely machine-independent and easy to port. Six accelerators presently use the software package with more scheduled to come on line soon.

For years, farmers in the United States have looked with envy on their European counterparts ability to profitably farm the wind through ownership of distributed, utility-scale wind projects. Only within the past few years, however, has farmer- or community-owned windpower development become a reality in the United States. The primary hurdle to this type of development in the United States has been devising and implementing suitable business and legal structures that enable such projects to take advantage of tax-based federal incentives for windpower. This article discusses the limitations of such incentives in supporting farmer- or community-owned wind projects, describes four ownership structures that potentially overcome such limitations, and finally conducts comparative financial analysis on those four structures, using as an example a hypothetical 1.5 MW farmer-owned project located in the state of Oregon. We find that material differences in the competitiveness of each structure do exist, but that choosing the best structure for a given project will largely depend on the conditions at hand; e.g., the ability of the farmer(s) to utilize tax credits, preference for individual versus cooperative ownership, and the state and utility service territory in which the project will be located.

We describe the fabrication and assembly of the first prototype 201. 25 MHz copper cavity for the muon ionization cooling experiment (MICE). This cavity was developed by the US MUCOOL collaboration and will be tested in the new MUCOOL Test Area at Fermilab. We outline the component and subassembly fabrication steps and the various metal forming and joining methods used to produce the final cavity shape. These include spinning, brazing, TIG welding, electron beam welding, electron beam annealing and deep drawing. Some of the methods developed for this cavity are novel and offer significant cost savings over conventional methods.

Colloidal nanocrystals are nanometer-sized, solution-grown inorganic particles stabilized by a layer of surfactants attached to their surface. The inorganic cores exhibit useful properties controlled by composition as well as size and shape, while the surfactant coating ensures that these structures are easy to fabricate and process. It is this combination of features that makes colloidal nanocrystals attractive and promising building blocks for advanced materials and devices. But their full potential can only be exploited if we achieve exquisite control over their composition, size, shape, crystal structure and surface properties. Here we review what is known about nanocrystal growth and outline strategies for controlling it.

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The Bi(111) surface was studied by scanning tunneling microscopy (STM), transmission electron microscopy (TEM) and angle-resolved photoemission (ARPES) in order to verify the existence of a recently proposed surface charge density wave (CDW) [Ch. R. Ast and H. Hoechst Phys. Rev. Lett. 90, 016403 (2003)]. The STM and TEM results to not support a CDW scenario at low temperatures. Furthermore, the quasiparticle interference pattern observed in STM confirms the spin-orbit split character of the surface states which prevents the formation of a CDW, even in the case of good nesting. The dispersion of the electronic states observed with ARPES agrees well with earlier findings. In particular, the Fermi contour of the electron pocket at the centre of the surface Brillouin zone is found to have a hexagonal shape. However, no gap opening or other signatures of a CDW phase transition can be found in the temperature-dependent data.

We describe a technique for the generation of an isolated burst of X-ray radiation with a duration of {approx} 100 attoseconds in a free electron laser (FEL) employing self-amplified spontaneous emission. Our scheme relies on an initial interaction of the electron beam with an ultra-short laser pulse in a one-period wiggler followed by compression in a dispersive section. The result of this interaction is to create a sub-femtosecond slice of the electron beam with enhanced growth rates for FEL amplification. After many gain lengths through the FEL undulator, the X-ray output from this slice dominates the radiation of the entire bunch. We consider the impact of various effects on the efficiency of this technique. Different configurations are considered in order to realize various timing structures for the resulting radiation.

Capillary channels of cm-length and at plasma density low compared to gas jets are promising setups for low noise laser wakefield acceleration. Computationally, however, the large discrepancy of the length scales of the plasma and the laser are a big challenge. Methods are therefore sought that relax the need to concurrently resolve both length scales. Average methods, which split the electromagnetic field into a fast and a slowly varying part, allow to relax the constraint to resolve the laser wavelength. Such an envelope model is currently being incorporated into the VORPAL plasma simulation code. Simulation results for benchmark cases and for laser pulse propagation in a cm-scale channel are presented.

While there has been strong support for Amborella and Nymphaeales (water lilies) as branching from basal-most nodes in the angiosperm phylogeny, this hypothesis has recently been challenged by phylogenetic analyses of 61 protein-coding genes extracted from the chloroplast genome sequences of Amborella, Nymphaea and 12 other available land plant chloroplast genomes. These character-rich analyses placed the monocots, represented by three grasses (Poaceae), as sister to all other extant angiosperm lineages. We have extracted protein-coding regions from draft sequences for six additional chloroplast genomes to test whether this surprising result could be an artifact of long-branch attraction due to limited taxon sampling. The added taxa include three monocots (Acorus, Yucca and Typha), a water lily (Nuphar), a ranunculid(Ranunculus), and a gymnosperm (Ginkgo). Phylogenetic analyses of the expanded DNA and protein datasets together with microstructural characters (indels) provided unambiguous support for Amborella and the Nymphaeales as branching from the basal-most nodes in the angiospermphylogeny. However, their relative positions proved to be dependent on method of analysis, with parsimony favoring Amborella as sister to all other angiosperms, and maximum likelihood and neighbor-joining methods favoring an Amborella + Nympheales clade as sister. The maximum likelihood phylogeny supported the later hypothesis, but the likelihood for …

The rf R&D program for high-gradient, low frequency cavities to be used in muon cooling systems is underway in the Fermilab MUCOOL Test Area. Cavities at 805 and 201 MHz are used for tests of conditioning techniques, surface modification and breakdown studies. This work has the Muon Ionization Cooling Experiment (MICE) as its immediate goal and efficient muon cooling systems for neutrino sources and muon colliders as the long term goal. We study breakdown and dark current production under a variety of conditions.

A Small Column Ion Exchange (SCIX) system, designed by the Oak Ridge and Savannah River National Laboratories (ORNL and SRNL), is a potential way to reduce Cs-137 concentrations in high-level radioactive waste at the Savannah River Site (SRS). SRNL has developed gamma-ray monitors for six locations within the SCIX system to verify the proper operation of the ion exchange system, detect cesium breakthrough, and confirm the presence of cesium before and after used resin is transferred to a grinder module. Two sodium iodide breakthrough monitors, one Geiger-Mueller breakthrough monitor, and three Geiger-Mueller transfer monitors were used. The present work provides a means of measuring the Cs-137 and Ba-137m breakthrough by taking multiple measurements in a process flow diversion and isolation loop. A lead shield was used for the NaI detectors, and the aperture of the collimator tube in this shield was designed using Monte Carlo analyses to provide the desired count rate for the gamma rays of interest. A computer program was written to collect data from the process monitors, provide alarm notification, and plot the data for ease of operation.

When planning the design of high-current FODO transport for accelerators, it is useful to have simple, accurate tools for calculating quantities such as the phase advances {sigma}{sub 0} and !given the lattice and beam parameters. Along with the KV beam model, the smooth approximation is often used. It is simple but not very accurate in many cases. Although Struckmeier and Reiser [1] showed that the stable oscillation frequencies of mismatched beams could be obtained accurately, they actually used a hybrid approach where {sigma}{sub 0} and {sigma} were already known precisely. When starting instead with basic quantities such as quadrupole dimensions, field strength, beam line charge density and emittance, the smooth approximation gives substantial errors. Here we derive a simple modification of the smooth approximation formula that improves the accuracy of the predicted frequencies by a factor of five at {sigma}{sub 0} = 83{sup o}.

Sediments found in waterways around the world may contain toxic compounds of anthropogeilic origin that can harm the environment and human health. As a result, it is often necessary to remove them and find disposal methods that are environmentally and economically acceptable. Here, we report on results obtained in an experimental program to characterize the nature of the sediment contamination. The objective was to gain a better understanding of the properties of the sediments to develop better methods for understanding the fate and transport of the contaminants and for improving methods for their removal from the sediments. Our investigations made use of x-ray facilities at the Brookhaven National Synchrotron Light Source (NSLS) and the European Synchrotron Radiation Facility (ESRF) at Grenoble, France. The experiments included: measurements of the microstructure of the sediments using computed microtomography, x-ray absorption, and fluorescence microscopy with resolutions as low as 0.2 micrometers to obtain information on the relationships of organic and mineral components of the sediments and on the distribution of contaminants on the surfaces of the sediment grains, investigation of functional groups of chemical compounds using x-ray absorption near-edge spectroscopy (XANES) and Fourier Transform Infrared Spectroscopy (FTIR). Scanning electron microscopy (SEM) and electron probe …

Quantum Efficiency (QE) measurements of single photon photoemission from a Cu(111) single crystal and a Cu polycrystal photocathodes, irradiated by 150 fs-6.28 eV laser pulses, are reported over a broad range of incidence angle, both in s and p polarizations. The maximum QE (approx. = 4x10-4) for polycrystalline Cu is obtained in p polarization at an angle of incidence theta = 65 deg. We observe a QE enhancement in p polarization which can not be explained in terms of optical absorption, a phenomenon known as vectorial photoelectric effect. Issues concerning surface roughness and symmetry considerations are addressed. An explanation in terms of non local conductivity tensor is proposed.

The origin of surface core-level shift (SCLS) of Pd thin films on Pt(111) substrate is investigated. At sub-monolayer coverage of Pd thin films, the splitting of Pd 3d core level peaks indicate the contribution of both initial and final-state of photo-ionization processes while there is almost no change on valence band (VB) spectra. When the coverage of Pd reaches to single monolayer, the final-state relaxation effect on the Pd 3d vanishes and only the initial-state effect, a negative SCLS, is present. Also, the VB spectrum at Pd monolayer films shows a clear band narrowing, that is the origin of the negative SCLS at monolayer coverage. As the Pd coverage is increased to more than monolayer thickness, the Pd 3d peaks start to show the surface layer contribution from second and third layers, positive SCLS, and the VB spectrum shows even narrower band width, possibly due to the formation of surface states and strained effect of Pd adlayers on top of the first pseudomorphic layer.

A detailed study of exchange-biased Fe/MnF{sub 2} bilayers using magneto-optical Kerr Effect shows that the magnetization reversal occurs almost fully through domain wall nucleation and propagation for external fields parallel to the exchange bias direction. For finite angles {phi} between bias and external field the magnetization is aligned perpendicular to the field cooling direction for a limited field range for decreasing fields. For external fields perpendicular to the bias direction the magnetization aligns with the field cooling direction for descending and ascending fields before fully reversing. The field range for which the magnetization is close to perpendicular to the external field can be estimated using a simple effective field model.

We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and antiferromagnet. The new uncompensated magnetization near the interface responds to applied field, while the uncompensated spins in the antiferromagnetic bulk are pinned, thus providing a means to establish exchange bias.

Epithelial cancers are associated with genomic instability and alterations in signaling pathways that affect proliferation, apoptosis, and integrity of tissue structure. Overexpression of a number of oncogenic protein kinases has been shown to malignantly transform cells in culture and to cause tumors in vivo, but the interconnected signaling events induced by transformation still awaits detailed dissection. We propose that the network of cellular signaling pathways can be classified into functionally distinct branches, and that these pathways are rewired in transformed cells and tissues after they lose tissue-specific architecture to favor tumor expansion and invasion. Using three-dimensional (3D) culture systems, we recently demonstrated that polarity and proliferation of human mammary epithelial cancer cells were separable consequences of signaling pathways downstream of PI3 kinase.These, and results from a number of other laboratories are beginning to provide insight into how different signaling pathways may become interconnected in normal tissues to allow homeostasis, and how they are disrupted during malignant progression.

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Gas reactor systems are being considered as candidates for use in generating power for the Prometheus-1 spacecraft, along with other NASA missions as part of the Prometheus program. Gas reactors offer a benign coolant, which increases core and structural materials options. However, the gas coolant has inferior thermal transport properties, relative to other coolant candidates such as liquid metals. This leads to concerns for providing effective heat transfer and for minimizing pressure drop within the reactor core. In direct gas Brayton systems, i.e. those with one or more Brayton turbines in the reactor cooling loop, the ability to provide effective core cooling and low pressure drop is further constrained by the need for a low pressure, high molecular weight gas, typically a mixture of helium and xenon. Use of separate primary and secondary gas loops, one for the reactor and one or more for the Brayton system(s) separated by heat exchanger(s), allows for independent optimization of the pressure and gas composition of each loop. The reactor loop can use higher pressure pure helium, which provides improved heat transfer and heat transport properties, while the Brayton loop can utilize lower pressure He-Xe. However, this approach requires a separate primary gas circulator …