Complexation of NpO2+ with oxalic acid (OX),2,2'-oxydiacetic acid (ODA), 2,2'-iminodiacetic acid (IDA) and 2,2'-thiodiacetic acid (TDA), has been studied using spectrophotometry in1 M NaClO4. Both the position and the intensity of the absorption band of NpO2+ at 980 nm are affected by the formation of NpO2+/dicarboxylate complexes, providing useful information on the complexation strength, the coordination mode and the structure of the complexes.

Colleagues of mine have asked me few times why we have today so much interest in Fixed-Field Alternating-Gradient (FFAG) accelerators when these were invented a long time ago, and have always been ignored since then. I try here to give a reply with a short history of FFAG accelerators, at least as I know it. I take also the opportunity to clarify few definitions.

It will be challenging to measure the temporal profile of the hard X-ray SASE beam independently from the electron beam in the LCLS and other 4th generation light sources. A fast interaction mechanism is needed that can be probed by an ultrafast laser pulse in a pump-probe experiment. It is proposed to exploit the rotation in polarization of light reflected from a thin magnetized film, known as the surface magneto optic Kerr effect (SMOKE), to witness the absorption of the x-ray pulse in the thin film. The change in spin orbit coupling induced by the x-ray pulse occurs on the subfemtosecond time scale and changes the polarization of the probe beam. The limitation to the technique lies with the bandwidth of the probe laser pulse and how short the optical pulse can be made. The SMOKE mechanism will be described and the choices of materials for use with 1.5 {angstrom} x-rays. A schematic description of the pump-probe geometry for x-ray diagnosis is also described.

The influence of GaSb substrate surface defects such as native oxides on the crystalline quality of epitaxial layers was investigated using transmission electron microscopy (TEM). Cross sectional TEM imaging showed that there are discrete defects at the GaSb-substrate/epilayer interface. Secondary ion mass spectroscopy (SIMS) results revealed high oxygen concentration at the interface, indicating that the defects are likely oxides and presumed to be native oxides since other impurities were not detected. High resolution TEM micrographs showed that the subsequent growth of the epilayer continues beyond the defects without any additional defect generation or propagation. Tellurium doped AlGaAsSb epitaxial layers were grown lattice-matched on GaSb substrates and lattice-mismatched on semi-insulating GaAs substrates by organometallic vapor phase epitaxy. Secondary ion mass spectroscopy and Hall data showed that the ratio of carrier concentration to Te concentration decreases significantly when the carrier concentration increases from 2.5 x 10{sup 17} cm{sup -3} to 6.5 x 10{sup 17} cm{sup -3}. TEM imaging showed that the material with heavily doped Te generates a high density (about 10{sup 8} cm{sup 2}) of planar defects (stacking fault) located on (111) planes. Most of the Te-related defects originate at the GaSb buffer layer/AlGaAsSb epilayer interface. In addition, discrete precipitates were …

The soft x-ray imager (SXRI) built for the first experiments at the National Ignition Facility (NIF) has four soft x-ray channels and one hard x-ray channel. The SXRI is a snout that mounts to a four strip gated imager. This produces four soft x-ray images per strip, which can be separated in time by {approx}60psec. Each soft x-ray channel consists of a mirror plus a filter. The diagnostic was used to study x-ray burnthrough of hot hohlraum targets at the NIF and OMEGA lasers. The SXRI snout design and issues involved in selecting the desired soft x-ray channels are discussed.

Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is utilized to examine the mass spectra and fragmentation patterns of seven isomeric monosaccharides. Multivariate statistical analysis techniques, including principal component analysis (PCA), allow discrimination of the extremely similar mass spectra of stereoisomers. Furthermore, PCA identifies those fragment peaks which vary significantly between spectra. Heavy isotope studies confirm that these peaks are indeed sugar fragments, allow identification of the fragments, and provide clues to the fragmentation pathways. Excellent reproducibility is shown by multiple experiments performed over time and on separate samples. This study demonstrates the combined selectivity and discrimination power of ToF-SIMS and PCA, and suggests new applications of the technique including differentiation of subtle chemical changes in biological samples that may provide insights into cellular processes, disease progress, and disease diagnosis.

We provide string theory examples where a toy model of a SUSY GUT or the MSSM is embedded in a compactification along with a gauge sector which dynamically breaks supersymmetry. We argue that by changing microscopic details of the model (such as precise choices of flux), one can arrange for the dominant mediation mechanism transmitting SUSY breaking to the Standard Model to be either gravity mediation or gauge mediation. Systematic improvement of such examples may lead to top-down models incorporating a solution to the SUSY flavor problem.

Complexation of Np(V), U(VI) and Nd(III) with dimethyl-3-oxa-glutaramic acid (DMOGA) and tetramethyl-3-oxa-glutaramide (TMOGA) was studied in comparison with the complexation with oxydiacetic acid (ODA). Stability constants and enthalpy of complexation were determined by potentiometry, spectrophotometry and calorimetry. Thermodynamic parameters, in conjunction with structural information of solid compounds, indicate that DMOGA and TMOGA form tridentate complexes with the ether-oxygen participating in bonding with actinide/lanthanide ions. The trends in the stability constants, enthalpy and entropy of complexation are discussed in terms of the difference in the hydration of the amide groups and carboxylate groups and the difference in the charge density of the metal ions.

The authors observe a new D{sub s} meson with mass (2856.6 {+-} 1.5{sub stat.} {+-} 5.0{sub syst.}) MeV/c{sup 2} and width (48 {+-} 7{sub stat.} {+-} 10{sub syst.}) MeV/c{sup 2} decaying into D{sup 0}K{sup +} and D{sup +}K{sub S}{sup 0}. In the same mass distributions they also observe a broad structure with mass (2688 {+-} 4{sub stat.} {+-} 3{sub syst.}) MeV/c{sup 2} and width (112 {+-} 7{sub stat.} {+-} 36{sub syst.}) MeV/c{sup 2}. To obtain this result they use 240 fb{sup -1} of data recorded by the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} storage rings at the Stanford Linear Accelerator Center running at center-of-mass energies near 10.6 GeV.

Lawrence Livermore National Laboratory (LLNL) is developing and fielding advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical, biological, radiological, nuclear, and explosive (CBRNE) weapons. The science, technology, and integrated systems we provide are informed by and developed with key partners and end users. LLNL's long-standing role as one of the two principle U.S. nuclear weapons design laboratories has led to significant resident expertise for health effects of exposure to radiation, radiation detection technologies, characterization of radioisotopes, and assessment and response capabilities for terrorist nuclear weapons use. This paper provides brief overviews of a number of technologies developed at LLNL that are being used to address national security needs to confront the growing threats of CBRNE terrorism.

Thomson scattering has been shown to be a valuable technique for measuring the plasma conditions in laser produced plasmas. Measurement techniques are discussed that use the ion-acoustic frequency measured from the collective Thomson-scattering spectrum to extract the electron temperature, ion temperature, plasma flow, and electron density in a laser produced plasma. In a recent study, they demonstrated a novel Thomson-scattering technique to measure the dispersion of ion-acoustic fluctuations that employing multiple color Thomson-scattering diagnostics. They obtained frequency-resolved Thomson-scattering spectra of the two separate thermal ion-acoustic fluctuations with significantly different wave vectors. This new technique allows a simultaneous time resolved local measurement of electron density and temperature. The plasma fluctuations are shown to become dispersive with increasing electron temperature. Furthermore, a Thomson-scattering technique to measure the electron temperature profile is presented where recent experiments have measured a large electron temperature gradient (Te = 1.4 keV to Te = 3.2 keV over 1.5-mm) along the axis of a 2-mm long hohlraum when heated asymmetrically.

At concentrations below 60%, wet hydrofluoric acid (HF) is extremely corrosive to steels, stainless steels and reactive metals, such as titanium, zirconium, and tantalum. In fact, only a few metallic materials will withstand wet HF at temperatures above ambient. Among these are the nickel-copper (Ni-Cu) and nickel-chromium-molybdenum (Ni-Cr-Mo) alloys. Previous work has shown that, even with these materials, there are complicating factors. For example, under certain conditions, internal attack and stress corrosion cracking (SCC) are possible with the Ni-Cr-Mo alloys, and the Ni-Cu materials can suffer intergranular attack when exposed to wet HF vapors. The purpose of this work was to study further the response of the Ni-Cr-Mo alloys to HF, in particular their external corrosion rates, susceptibility to internal attack and susceptibility to HF-induced SCC, as a function of alloy composition. As a side experiment, one of the alloys was tested in two microstructural conditions, i.e. solution annealed (the usual condition for materials of this type) and long-range ordered (this being a means of strengthening the alloy in question). The study of external corrosion rates over wide ranges of concentration and temperature revealed a strong beneficial influence of molybdenum content. However, tungsten, which is used as a partial replacement …

Focusing of a 15 MeV, 16 nC electron bunch by a gaussian underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated. The strong 1.9 cm focal length plasma lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Time resolved measurements of the focused electron bunch are also reported and compared to simulations.

A large variety of corrosion resistant alloys are used regularly in the chemical process industry (CPI). The most common family of alloys include the iron (Fe)-based stainless steels, nickel (Ni) alloys and titanium (Ti) alloys. There also other corrosion resistant alloys but their family of alloys is not as large as for the three groups mentioned above. All ranges of corrosive environments can be found in the CPI, from caustic solutions to hot acidic environments, from highly reducing to highly oxidizing. Stainless steels are ubiquitous since numerous types of stainless steels exist, each type tailored for specific applications. In general, stainless steels suffer stress corrosion cracking (SCC) in hot chloride environments while high Ni alloys are practically immune to this type of attack. High nickel alloys are also resistant to caustic cracking. Ti alloys find application in highly oxidizing solutions. Solutions containing fluoride ions, especially acid, seem to be aggressive to almost all corrosion resistant alloys.

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being …

Moss et al.(2005) describe, in a recent paper, a filter thatthey use to detect lines. We noticed that the wavelet on which thisfilter is based is a difference of uniform filters. This filter is anapproximation to the second derivative operator, which is commonlyimplemented as the Laplace of Gaussian (or Marr-Hildreth) operator (Marr&Hildreth, 1980; Jahne, 2002), Figure 1. We have compared Moss'filter with 1) the Laplace of Gaussian operator, 2) an approximation ofthe Laplace of Gaussian using uniform filters, and 3) a few common noisereduction filters. The Laplace-like operators detect lines by suppressingimage features both larger and smaller than the filter size. The noisereduction filters only suppress image features smaller than the filtersize. By estimating the signal to noise ratio (SNR) and mean squaredifference (MSD) of the filtered results, we found that the filterproposed by Moss et al. does not outperform the Laplace of Gaussianoperator. We also found that for images with extreme noise content, linedetection filters perform better than the noise reduction filters whentrying to enhance line structures. In less extreme cases of noise, thestandard noise reduction filters perform significantly better than boththe Laplace of Gaussian and Moss' filter.

The incidence of papillary thyroid carcinoma (PTC) increases significantly after exposure of the head and neck region to ionizing radiation, yet we know neither the steps involved in malignant transformation of thyroid epithelium nor the specific carcinogenic mode of action of radiation. Such increased tumor frequency became most evident in children after the 1986 nuclear accident in Chernobyl, Ukraine. In the twelve years following the accident, the average incidence of childhood PTCs (chPTC) increased over one hundred-fold compared to the rate of about 1 tumor incidence per 10{sup 6} children per year prior to 1986. To study the etiology of radiation-induced thyroid cancer, we formed an international consortium to investigate chromosomal changes and altered gene expression in cases of post-Chernobyl chPTC. Our approach is based on karyotyping of primary cultures established from chPTC specimens, establishment of cell lines and studies of genotype-phenotype relationships through high resolution chromosome analysis, DNA/cDNA micro-array studies, and mouse xenografts that test for tumorigenicity. Here, we report the application of fluorescence in situ hybridization (FISH)-based techniques for the molecular cytogenetic characterization of a highly tumorigenic chPTC cell line, S48TK, and its subclones. Using chromosome 9 rearrangements as an example, we describe a new approach termed ''BAC-FISH'' …

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Wind power production varies on a diurnal and seasonal basis. In this paper, we use wind speed data from three different sources to assess the effects of wind timing on the value of electric power from potential wind farm locations in California and the Northwestern United States. By ''value'', we refer to either the contribution of wind power to meeting the electric system's peak loads, or the financial value of wind power in electricity markets. Sites for wind power projects are often screened or compared based on the annual average power production that would be expected from wind turbines at each site (Baban and Parry 2001; Brower et al. 2004; Jangamshetti and Rau 2001; Nielsen et al. 2002; Roy 2002; Schwartz 1999). However, at many locations, variations in wind speeds during the day and year are correlated with variations in the electric power system's load and wholesale market prices (Burton et al. 2001; Carlin 1983; Kennedy and Rogers 2003; Man Bae and Devine 1978; Sezgen et al. 1998); this correlation may raise or lower the value of wind power generated at each location. A number of previous reports address this issue somewhat indirectly by studying the contribution of individual wind …

A relativistic many-body method is developed to calculate energy and transition rates for multipole transitions in many-electron ions. This method is based on relativistic many-body perturbation theory (RMBPT), agrees with MCDF calculations in lowest-order, includes all second-order correlation corrections and includes corrections from negative energy states. Reduced matrix elements, oscillator strengths, and transition rates are calculated for electric-multipole (dipole (E1), quadrupole (E2), and octupole (E3)) and magnetic-multipole (dipole (M1), quadrupole (M2), and octupole (M3)) transitions between 3l{sup -1}5l{prime} excited and ground states in Ni-like ions with nuclear charges ranging from Z = 30 to 100. The calculations start from a 1s{sup 2}s{sup 2}2p{sup 6}3s{sup 2}3p{sup 6}3d{sup 10} Dirac-Fock potential. First-order perturbation theory is used to obtain intermediate-coupling coefficients, and second-order RMBPT is used to determine the matrix elements. A detailed discussion of the various contributions to the dipole matrix elements and energy levels is given for nickel-like tungsten (Z = 74). The contributions from negative-energy states are included in the second order E1, M1, E2, M2, E3 and M3 matrix elements. The resulting transition energies and transition rates are compared with experimental values and with results from other recent calculations. These atomic data are important in modeling of M-shell radiation …

In a recent article it was argued that dynamic heterogeneity in d-dimensional glass formers is a manifestation of an order-disorder phenomenon in the d+1 dimensions of spacetime. By considering a dynamical analogue of the free energy, evidence was found for phase coexistence between active and inactive regions of spacetime, and it was suggested that this phenomenon underlies the glass transition. Here we develop these ideas further by investigating in detail the one-dimensional Fredrickson-Andersen (FA) model in which the active and inactive phases originate in the reducibility of the dynamics. We illustrate the phase coexistence by considering the distributions of mesoscopic spacetime observables. We show how the analogy with phase coexistence can be strengthened by breaking microscopic reversibility in the FA model, leading to a non-equilibrium theory in the directed percolation universality class.

GeV electron accelerators are essential to synchrotron radiation facilities and free electron lasers, and as modules for high-energy particle physics. Radio frequency based accelerators are limited to relatively low accelerating fields (10-50 MV/m) and hence require tens to hundreds of meters to reach the multi-GeV beam energies needed to drive radiation sources, and many kilometers to generate particle energies of interest to the frontiers of high-energy physics.Laser wakefield accelerators (LWFA) in which particles are accelerated by the field of a plasma wave driven by an intense laser pulse produce electric fields several orders of magnitude stronger (10-100 GV/m) and so offer the potential of very compact devices. However, until now it has not been possible to maintain the required laser intensity, and hence acceleration, over the several centimeters needed to reach GeV energies.For this reason laser-driven accelerators have to date been limited to the 100 MeV scale. Contrary to predictions that PW-class lasers would be needed to reach GeV energies, here we demonstrate production of a high-quality electron beam with 1 GeV energy by channeling a 40 TW peak power laser pulse in a 3.3 cm long gas-filled capillary discharge waveguide. We anticipate that laser-plasma accelerators based on capillary discharge …

Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. Both regular and high-frequency spectral components can be recovered from the data--the moire component carries additional information that increases the signal to noise for velocimetry and spectroscopy. Here we present simulations and theoretical studies of the photon limited Doppler velocity noise in an EDI. We used a model spectrum of a 1600K temperature star. For several rotational blurring velocities 0, 7.5, 15 and 25 km/s we calculated the dimensionless Doppler quality index (Q) versus wavenumber v. This is the normalized RMS of the derivative of the spectrum and is proportional to the photon-limited Doppler signal to noise ratio.

We propose a microscopic CFT description of magnetically charged black holes in IIA compactifications on elliptic fibrations based on the Fourier-Mukai transform. The physical derivation of this model involves a chain of string duality transformations including the 4D/5D black hole correspondence. We compute the asymptotic behavior of the microstate degeneracy in a certain limit of large charges and show that it agrees with the macroscopic entropy formula. An interesting aspect of this setup is that the attractor points are situated deep in a hybrid phase of the quantum Kaehler moduli space.