We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 {micro}J for individual pulses, and the average energy per pulse reached 70 {micro}J. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20mW. The output beam also contained a significant contribution from odd harmonics of approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.

In a world with water resources severely impacted bytechnology, science must actively contribute to water law. To this end,this paper is an earth scientist s attempt to comprehend essentialelements of water law, and to examine their connections to science.Science and law share a common logical framework of starting with apriori prescribed tenets, and drawing consistent inferences. In science,observationally established physical laws constitute the tenets, while inlaw, they stem from social values. The foundations of modern water law inEurope and the New World were formulated nearly two thousand years ago byRoman jurists who were inspired by Greek philosophy of reason.Recognizing that vital natural elements such as water, air, and the seawere governed by immutable natural laws, they reasoned that theseelements belonged to all humans, and therefore cannot be owned as privateproperty. Legally, such public property was to be governed by jusgentium, the law of all people or the law of all nations. In contrast,jus civile or civil law governed private property. Remarkably, jusgentium continues to be relevant in our contemporary society in whichscience plays a pivotal role in exploiting vital resources common to all.This paper examines the historical roots of modern water law, followstheir evolution through the centuries, and examines how …

None

Inter-plant concentration ratios (IPCR), [Bq g{sup -1} {sup 137}Cs in coral atoll tree food-crops/Bq g{sup -1} {sup 137}Cs in leaves of native plant species whose roots share a common soil volume], can replace transfer factors (TF) to predict {sup 137}Cs concentration in tree food-crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact tree roots naturally integrate 137Cs over large volumes of soil. Root absorption of {sup 137}Cs replaces large-scale, expensive soil sampling schemes to reduce variability in {sup 137}Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSD's of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF …

Lattice level measurements of material response under extreme conditions are required to build a phenomenological understanding of the shock response of solids. We have successfully used laser produced plasma x-ray sources coincident with laser driven shock waves to make in-situ measurements of the lattice response during shock compression for both single crystal and polycrystalline materials. Using a detailed analysis of shocked single crystal iron which has undergone the {alpha} - {var_epsilon} phase transition we can constrain the transition mechanism to be consistent with a compression and shuffle of alternate lattice planes.

The Savannah River National Laboratory's (SRNL) Atmospheric Technologies Group develops, maintains, and operates computer-based software applications for use in emergency response consequence assessment at DOE's Savannah River Site. These applications range from straightforward, stand-alone Gaussian dispersion models run with simple meteorological input to complex computational software systems with supporting scripts that simulate highly dynamic atmospheric processes. A software quality assurance program has been developed to ensure appropriate lifecycle management of these software applications. This program was designed to meet fully the overall structure and intent of SRNL's institutional software QA programs, yet remain sufficiently practical to achieve the necessary level of control in a cost-effective manner. A general overview of this program is described.

Modern single molecule fluorescence microscopy offers new, highly quantitative ways of studying the systems biology of cells while keeping the cells healthy and alive in their natural environment. In this context, a quantum optical technique, photon antibunching, has found a small niche in the continuously growing applications of single molecule techniques to small molecular complexes. Here, we review some of the most recent applications of photon antibunching in biophotonics, and we provide a guide for how to conduct photon antibunching experiments at the single molecule level by applying techniques borrowed from time-correlated single photon counting. We provide a number of new examples for applications of photon antibunching to the study of multichromophoric molecules and small molecular complexes.

We show a calculable example of stable supersymmetry (SUSY) breaking modelswith O(10) eV gravitino mass based on the combination of D-term gauge mediationand U(1)' mediation. A potential problem of the negative mass squared for theSUSY standard model (SSM) sfermions in the D-term gauge mediation is solvedby the contribution from the U(1)' mediation. On the other hand, the splittingbetween the SSM gauginos and sfermions in the U(1)' mediation iscircumvented bythe contributions from the D-term gauge mediation. Since the U(1)' mediation doesnot introduce any new SUSY vacua, we achieve a completely stable model underthermal effects. Our model, therefore, has no cosmological difficulty.

Charge-changing and fragment production cross sections at 0circ have been obtained for interactions of 290 MeV/nucleon and 400MeV/nucleon carbon beams with C, CH2, Al, Cu, Sn, and Pb targets. Thesebeams are relevant to cancer therapy, space radiation, and the productionof radioactive beams. We compare to previously published results using Cand CH2 targets at similar beam energies. Due to ambiguities arising fromthe presence of multiple fragments on many events, previous publicationshave reported only cross sections for B and Be fragments. In this work wehave extracted cross sections for all fragment species, using dataobtained at three distinct values of angular acceptance, supplemented bydata taken with the detector stack placed off the beam axis. A simulationof the experiment with the PHITS Monte Carlo code shows fair agreementwith the data obtained with the large acceptance detectors, but agreementis poor at small acceptance. The measured cross sections are alsocompared to the predictions of the one-dimensional cross section modelsEPAX2 and NUCFRG2; the latter is presently used in NASA's space radiationtransport calculations. Though PHITS and NUCFRG2 reproduce thecharge-changing cross sections with reasonable accuracy, none of themodels is able to accurately predict the fragment cross sections for allfragment species and target materials.

None

T-474 at SLAC is a prototype BPM-based energy spectrometer for the ILC. We describe magnetic measurements and simulations for the 4-magnet chicane used in T-474.

We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and Kuiper Belt strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. If detected, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic, especially near the Galactic center and for signals at high Galactic latitudes, such as the extragalactic {gamma}-ray emission. Additionally, it can be used to probe the spectrum of CR nuclei at close-to-interstellar conditions, and the mass spectrum of small bodies in the Main Belt and Kuiper Belt. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory …

The isotropic elastic wave equation governs the propagation of seismic waves caused by earthquakes and other seismic events. It also governs the propagation of waves in solid material structures and devices, such as gas pipes, wave guides, railroad rails and disc brakes. In the vast majority of wave propagation problems arising in seismology and solid mechanics there are free surfaces. These free surfaces have, in general, complicated shapes and are rarely flat. Another feature, characterizing problems arising in these areas, is the strong heterogeneity of the media, in which the problems are posed. For example, on the characteristic length scales of seismological problems, the geological structures of the earth can be considered piecewise constant, leading to models where the values of the elastic properties are also piecewise constant. Large spatial contrasts are also found in solid mechanics devices composed of different materials welded together. The presence of curved free surfaces, together with the typical strong material heterogeneity, makes the design of stable, efficient and accurate numerical methods for the elastic wave equation challenging. Today, many different classes of numerical methods are used for the simulation of elastic waves. Early on, most of the methods were based on finite difference approximations …

Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

The EBIT spectroscopy that now seems routine would not be possible without considerable good luck in several areas of EBIT technology. Among these are x-ray background, ion cooling, neutral gas density, and electron current density and energy control. A favourable outcome in these areas has enabled clean x-ray spectra, sufficient intensity for high resolution spectroscopy, production of very high charge states, and a remarkable variety of spectroscopic measurements. During construction of the first EBIT 20 years ago, it was not clear that any of this was possible.

High-voltage vacuum insulator failure is generally due to surface flashover rather than insulator bulk breakdown. Vacuum surface flashover is widely believed to be initiated by a secondary electron emission avalanche along the vacuum-insulator interface. This process requires a physical mechanism to cause secondary electrons emitted from the insulator surface to return to that surface. Here, we show that when an insulator is subjected to a fast high-voltage pulse, the magnetic field due to displacement current through the insulator can provide this mechanism. This indicates the importance of the voltage pulse shape, especially the rise time, in the flashover initiation process.

A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO2 production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

A single parameter, the gravitational growth index gamma, succeeds in characterizing the growth of density perturbations in the linear regime separately from the effects of the cosmic expansion. The parameter is restricted to a very narrow range for models of dark energy obeying the laws of general relativity but can take on distinctly different values in models of beyond-Einstein gravity. Motivated by the parameterized post-Newtonian (PPN) formalism for testing gravity, we analytically derive and extend the gravitational growth index, or Minimal Modified Gravity, approach to parameterizing beyond-Einstein cosmology. The analytic formalism demonstrates how to apply the growth index parameter to early dark energy, time-varying gravity, DGP braneworld gravity, and some scalar-tensor gravity.

We present the initial results of an experimental study of abeam timing monitor based on an optoelectronic technique. This techniqueuses the electrical signal from a beam position monitor to modulate theamplitude of a train of laser pulses, converting timing jitter into anamplitude jitter. This modulation is then measured with a photodetectorand sampled by a fast ADC. This approach has already demonstrated sub-100fs resolution and promises even better results. Additionally, we areplanning to use the technique as a way to extract the maximum possiblebandwidth from a BPM, avoiding the dispersion typical of long RF cables.We show our initial results using signals from the Advanced Light Sourcestorage ring.

In this study we investigate the formation and properties of prestellar and protostellar cores using hydrodynamic, self-gravitating Adaptive Mesh Refinement simulations, comparing the cases where turbulence is continually driven and where it is allowed to decay. We model observations of these cores in the C{sup 18}O(2 {yields} 1), NH{sub 3}(1, 1), and N{sub 2}H{sup +}(1 {yields} 0) lines, and from the simulated observations we measure the linewidths of individual cores, the linewidths of the surrounding gas, and the motions of the cores relative to one another. Some of these distributions are significantly different in the driven and decaying runs, making them potential diagnostics for determining whether the turbulence in observed star-forming clouds is driven or decaying. Comparing our simulations with observed cores in the Perseus and {rho} Ophiuchus clouds shows reasonably good agreement between the observed and simulated core-to-core velocity dispersions for both the driven and decaying cases. However, we find that the linewidths through protostellar cores in both simulations are too large compared to the observations. The disagreement is noticeably worse for the decaying simulation, in which cores show highly supersonic in fall signatures in their centers that decrease toward their edges, a pattern not seen in the observed …

The ANSI N43.1 Standard, currently in revision (ANSI 2007), sets forth the requirements for accelerator facilities to provide adequate protection for the workers, the public and the environment from the hazards of ionizing radiation produced during and from accelerator operations. The Standard also recommends good practices that, when followed, provide a level of radiation protection consistent with those established for the accelerator communities. The N43.1 Standard is suitable for all accelerator facilities (using electron, positron, proton, or ion particle beams) capable of producing radiation, subject to federal or state regulations. The requirements (see word 'shall') and recommended practices (see word 'should') are prescribed in a graded approach that are commensurate with the complexity and hazard levels of the accelerator facility. Chapters 4, 5 and 6 of the N43.1 Standard address specially the Radiation Safety System (RSS), both engineered and administrative systems, to mitigate and control the prompt radiation hazards from accelerator operations. The RSS includes the Access Control System (ACS) and Radiation Control System (RCS). The main requirements and recommendations of the N43.1 Standard regarding the management, technical and operational aspects of the RSS are described and condensed in this report. Clearly some aspects of the RSS policies and practices …

We investigate unparticle physics with supersymmetry (SUSY). The SUSY breaking effects due to the gravity mediation induce soft masses for the SUSY unparticles and hence break the conformal invariance. The unparticle physics observable in near future experiments is only consistent if the SUSY breakingeffects from the hidden sector to the standard model sector are dominated by the gauge mediation, or if the SUSY breaking effects to the unparticle sector are sufficiently sequestered. We argue that the natural realization of the latter possibility is the conformal sequestering scenario.

Back-to-back dihadron spectra in high-energy heavy-ioncollisions are studied within the next-to-leading order (NLO)perturbative QCD parton model with jet quenching incorporated viamodified jet fragmentation functions due to radiative parton energy lossin dense medium. The experimentally observed appearance of back-to-backdihadron sat high p_T is found to originate mainly from jet pairsproduced close and tangential to the surface of the dense matter.However, a substantial fraction of observed high p_T dihadrons also comesfrom jets produced at the center of the medium after losing finite amountof energy. Consequently, the suppression factor of such high-p_T hadronpairs is foundto be more sensitive to the initial gluon density than thesingle hadron spectra that are dominated by surface emission. Asimultaneous chi2-fit to both the single and dihadron spectra can beachieved within an arrow range of the energy loss parametersepsilon_0=1.6-2.1 GeV/fm. Because of the flattening of the initial jetproduction spectra, high p_T dihadrons at the LHC energy are found to bemore robust as probes of the dense medium.

Free sintering of SiC with Al, B, and C additions in two successive stages, first under nitrogen and then under argon, produced a near full-density ceramic with equiaxed grain structure. The beta to alpha transformation proceeded to completion; however, the grain shape remained equiaxed due to the action of nitrogen present during the first stage of sintering. It is found that the beta to alpha transformation is necessary but not sufficient for producing the microstructure of interlocking plates found in high-toughness SiC.