A specification is proposed for an initial transient benchmark analysis of the China Experimental Fast Reactor design based on the analysis capabilities of the SAS4A/SASSYS-1 code. For the initial benchmark, a single-channel protected transient overpower accident is defined. Reactivity feedback coefficients will not be required and simplified material properties are recommended. This report also describes the data required for developing the modeling input. This data includes assembly geometry, reactor power distributions, kinetics and decay heat data, and material properties. Comparisons of benchmark results will take place at a future SAS4A/SASSYS-1 training meeting planned to occur at Argonne National Laboratory. Future benchmark specifications will be planned to expand upon this initial model to include more complex reactivity feedback models, material properties, additional assembly geometry, and primary and intermediate coolant systems.

None

None

Persistent uranium contamination of groundwater under the 300 Area of the Hanford Site has been observed. The source of the uranium contamination resides in uranium deposits on sediments at the groundwater interface, and the contamination is mobilized when periodically wetted by fluctuations of Columbia River levels. Treatability work is ongoing to develop and apply phosphate-containing reagents to promote the formation of stable and insoluble uranium phosphate minerals (i.e., autunite) and other phosphate precipitates (di-calcium phosphate, apatite) to stabilize the uranium source. Technologies for applying phosphate-containing reagents by vertical percolation and lateral injection into sediments of the periodically wetted groundwater interface are being investigated. This report is a preliminary evaluation of technologies for lateral injection.

A scanning visible spectrometer has been prototyped to complement fixed-wavelength transmission grating spectrometers for charge exchange recombination spectroscopy. Fast f/1.8 200 mm commercial lenses are used with a large 2160 mm-1 grating for high throughput. A stepping-motor controlled sine drive positions the grating, which is mounted on a precision rotary table. A high-resolution optical encoder on the grating stage allows the grating angle to be measured with an absolute accuracy of 0.075 arcsec, corresponding to a wavelength error ≤ 0.005 Å. At this precision, changes in grating groove density due to thermal expansion and variations in the refractive index of air are important. An automated calibration procedure determines all relevant spectrometer parameters to high accuracy. Changes in bulk grating temperature, atmospheric temperature and pressure are monitored between the time of calibration and the time of measurement to insure a persistent wavelength calibration

Neutrino astronomy beyond the Sun was first imagined in the late 1950s; by the 1970s, it was realized that kilometer-scale neutrino detectors were required. The first such instrument, IceCube, is near completion and taking data. The IceCube project transforms a cubic kilometer of deep and ultra-transparent Antarctic ice into a particle detector. A total of 5,160 optical sensors are embedded into a gigaton of Antarctic ice to detect the Cherenkov light emitted by secondary particles produced when neutrinos interact with nuclei in the ice. Each optical sensor is a complete data acquisition system, including a phototube, digitization electronics, control and trigger systems and LEDs for calibration. The light patterns reveal the type (flavor) of neutrino interaction and the energy and direction of the neutrino, making neutrino astronomy possible. The scientific missions of IceCube include such varied tasks as the search for sources of cosmic rays, the observation of Galactic supernova explosions, the search for dark matter, and the study of the neutrinos themselves. These reach energies well beyond those produced with accelerator beams.

We study the impact of theoretical uncertainty in the dark matter halo mass function and halo bias on dark energy constraints from imminent galaxy cluster surveys. We find that for an optical cluster survey like the Dark Energy Survey, the accuracy required on the predicted halo mass function to make it an insignificant source of error on dark energy parameters is {approx}1%. The analogous requirement on the predicted halo bias is less stringent ({approx}5%), particularly if the observable-mass distribution can be well constrained by other means. These requirements depend upon survey area but are relatively insensitive to survey depth. The most stringent requirements are likely to come from a survey over a significant fraction of the sky that aims to observe clusters down to relatively low mass, M{sub th}{approx} 10{sup 13.7} h{sup -1} M{sub sun}; for such a survey, the mass function and halo bias must be predicted to accuracies of {approx}0.5% and {approx}1%, respectively. These accuracies represent a limit on the practical need to calibrate ever more accurate halo mass and bias functions. We find that improving predictions for the mass function in the low-redshift and low-mass regimes is the most effective way to improve dark energy constraints.

A diagnostic suite has been developed to measure impurity poloidal flow using charge exchange recombination spectroscopy on the National Spherical Torus Experiment. Toroidal and poloidal viewing systems measure all quantities required to determine the radial electric field. Two sets of up/down symmetric poloidal views are used to measure both active emission in the plane of the neutral heating beams and background emission in a radial plane away from the neutral beams. Differential velocity measurements isolate the line-integrated poloidal velocity from apparent flows due to the energy-dependent chargeexchange cross section. Six f/1.8 spectrometers measure 276 spectra to obtain 75 active and 63 background channels every 10 ms. Local measurements from a similar midplane toroidal viewing system are mapped into two dimensions to allow the inversion of poloidal line-integrated measurements to obtain local poloidal velocity profiles. Radial resolution after inversion is 0.6-1.8 cm from the plasma edge to the center.

The branching fraction for the decay D{sub s}{sup +} {yields} {tau}{sup +}{nu}{sub {tau}} with {tau}{sup +} {yields} e{sup +}{bar {nu}}{sub {tau}}, is measured using a data sample corresponding to an integrated luminosity of 427 fb{sup -1} collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. In the process e{sup +}e{sup -} {yields} c{bar c} {yields} D*{sub s}{sup +} {bar D}{sub TAG}{bar K}X, the D*{sub s}{sup +} meson is reconstructed as a missing particle, and the subsequent decay D*{sub s}{sup +} {yields} D{sub s}{sup +}{gamma} yields an inclusive D{sub s}{sup +} data sample. Here {bar D}{sub TAG} refers to a fully reconstructed hadronic {bar D} decay, {bar K} is a K{sup -} or {bar K}{sup 0}, and X stands for any number of charged or neutral pions. The decay D{sub s}{sup +} {yields} K{sub S}{sup 0}K{sup +} is isolated also, and from ratio of event yields and known branching fractions, {Beta}(D{sub s}{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (4.5 {+-} 0.5 {+-} 0.4 {+-} 0.3)% is determined. The pseudoscalar decay constant is extracted to be f{sub D{sub s}} = (233 {+-} 13 {+-} 10 {+-} 7) MeV, …

The goal of this project is to evaluate the extensive feasibility of a novel concept called Thermal Swing Sorption Enhanced Reaction (TSSER) process to simultaneously produce H{sub 2} and CO{sub 2} as a single unit operation in a sorber-reactor. The successful demonstration of the potential feasibility of the TSSER concept implies that it is worth pursuing further development of the idea. This can be done by more extensive evaluation of the basic sorptive properties of the CO{sub 2} chemisorbents at realistic high pressures and by continuing the experimental and theoretical study of the TSSER process. This will allow us to substantiate the assumptions made during the preliminary design and evaluation of the process and firm up the initial conclusions. The task performed under this project consists of (i) retrofitting an existing single column sorption apparatus for measurement of high pressure CO{sub 2} sorption characteristics, (ii) measurement of high pressure CO{sub 2} chemisorption equilibria, kinetics and sorption-desorption column dynamic characteristics under the conditions of thermal swing operation of the TSSER process, (iii) experimental evaluation of the individual steps of the TSSER process (iv) development of extended mathematical model for simulating cyclic continuous operation of TSSER to aid in process scale-up and …

It is shown that nonlinear self-interaction of energetic particle-driven Geodesic Acoustic Mode does not generate a second harmonic in radial electric field using the fluid model. However, kinetic effects of energetic particles can induce a second harmonic in the radial electric field. A formula for the second order plasma density perturbation is derived. It is shown that a second harmonic of plasma density perturbation is generated by the convective nonlinearity of both thermal plasma and energetic particles. Near the midplane of a tokamak, the second order plasma density perturbation (the sum of second harmonic and zero frequency sideband) is negative on the low field side with its size comparable to the main harmonic at low uctuation level. These analytic predictions are consistent with the recent experimental observation in DIII-D.

TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states 'GeV-Matter' that are charged under this force and constitute a small fraction of the dark matter halo. Dark higgsinos in a supersymmetric dark sector are natural candidates for GeV-Matter that scatter off protons with a universal cross-section of 5 x 10{sup -38} cm{sup 2} and can naturally be split by 10-30 keV so that their dominant interaction with protons is down-scattering. As an example, down-scattering of an O(5) GeV dark higgsino can simultaneously explain the spectra observed by both CoGeNT and DAMA. The event rates in these experiments correspond to a GeV-Matter abundance of 0.2-1% of the halo mass density. This abundance can arise directly from thermal freeze-out at weak coupling, or from the late decay of an unstable TeV-scale WIMP. Our proposal can be tested by searches for exotics in the BaBar and Belle datasets.

A new calculation of the production of 37Ar from nuclear explosion neutron interactions on 40Ca in a suite of common sub-surface materials (rock, etc) is presented. Even in mineral structures that are relatively low in Ca, the resulting 37Ar signature is large enough for detection in cases of venting or gaseous diffusion driven by barometric pumping. Field and laboratory detection strategies and projected sensitivities are presented.

None

We create a transient Bragg grating in a high harmonic generation medium using two counterpropagating pulses. The Bragg grating disperses the harmonics in angle and can diffract a large bandwidth with temporal resolution limited only by the source size.

Collimators and transitions in accelerator vacuum chambers often include small-angle tapering to lower the wakefields generated by the beam. While the low-frequency impedance is well described by Yokoya's formula (for axisymmetric geometry), much less is known about the behavior of the impedance in the high frequency limit. In this paper we develop an analytical approach to the highfrequency regime for round collimators and tapers. Our analytical results are compared with computer simulations using the code ECHO.

We report on long exposure results obtained with a Teledyne HyViSI H2RG detector operating in guide mode. The sensor simultaneously obtained nearly seeing-limited data while also guiding the Kitt Peak 2.1 m telescope. Results from unguided and guided operation are presented and used to place lower limits on flux/fluence values for accurate centroid measurements. We also report on significant noise reduction obtained in recent laboratory measurements that should further improve guiding capability with higher magnitude stars.

It is well-known that seeding can be used to produce narrow-bandwidth and fully-coherent x- ray free-electron lasers. Self-seeding, which uses an extra undulator to generate the seed pulse, is perhaps one of the most promising methods to accomplish this. In the hard x-ray regime with high- energy electrons, this method requires a large magnetic chicane to match the path length delay of the x-ray monochromator that selects a narrow bandwidth of radiation. Such a chicane not only takes large footprint to build, but also may degrade the electron beam qualities through incoherent and coherent synchrotron radiation. In this paper, we present an alternative two-bunch self-seeding scheme. The two bunches are precisely separated to match the x-ray delay of the monochromator and eliminate the need for a long, complex magnetic chicane. The spectrally filtered SASE x-ray pulse produced by the first bunch is combined with the second electron bunch at the entrance of the second undulator and then amplified to the saturation level. We present start-to-end simulation results based on the LCLS hard x-ray FEL and show that this method can produce a nearly fully coherent x-ray pulse at a few GW power level.

We have investigated the doping and temperature dependences of the pseudogap/superconducting gap in the single-layer cuprate La{sub 2-x}Sr{sub x}CuO{sub 4} by angle-resolved photoemission spectroscopy. The results clearly exhibit two distinct energy and temperature scales, namely, the gap around ({pi}, 0) of magnitude {Delta}{asterisk} and the gap around the node characterized by the d-wave order parameter {delta}{sub 0}, like the double-layer cuprate Bi2212. In comparison with Bi2212 having higher T{sub c}'s, {delta}{sub 0} is smaller, while {delta}{asterisk} and T{ampersand} are similar. This result suggests that {delta}{asterisk} and T{asterisk} are approximately material-independent properties of a single Cu0{sub 2} plane, in contrast the material-dependent {delta}{sub 0}, representing the pairing strength.