Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool designed for 3D resistivity imaging around a single borehole. The tool was developed for deployment in high temperature geothermal wells under a joint program funded by the California Energy Commission, Electromagnetic Instruments (EMI) and the U.S. Department of Energy. EM1 was responsible for tool design and manufacture, and numerical modeling efforts were being addressed at Lawrence Livermore Laboratory (LLNL) and other contractors. The field deployment was done by EM1 and LLNL. The tool operates at frequencies from 2 to 42 kHz, and its design features a series of three-component magnetic sensors offset at 2 and 5 meters from a three-component magnetic source. The combined package makes it possible to do 3D resistivity imaging, deep into the formation, from a single well. The manufacture and testing of the tool was completed in spring of 2001, and the initial deployment of Geo-BILT occurred in May 2001 at the Lost Hills oil field in southern California at leases operated by Chevron USA. This site was chosen for the initial field test because of the favorable geological conditions and the availability of a number of wells suitable for tool deployment. The second …

Recent measurements of the asymmetries between Feynman x-distributions of strange and antistrange hadrons in {pi}{sup -}A interactions show a strong effect as a function of x{sub F}. We calculate strange hadron production in the context of the intrinsic model and make predictions for particle/antiparticle asymmetries in these interactions.

Analytical expressions for three P-wave attenuation mechanisms in rocks are given and numerically-compared. The mechanisms are: (1) Biot loss, in which flow occurs at the scale of the wavelength between the peaks and troughs of a P wave; (2) squirt loss, in which flow occurs at the grain scale between microcracks the grains and the adjacent pores; and (3) mesoscopic loss, in which flow occurs at intermediate scales between the various lithological bodies that are present in an averaging volume of earth material. Each mechanism is of importance over different frequency bands. Typically, Biot loss is only important at the highest of ultrasonic frequencies (> 1 MHz), squirt-loss (when it occurs) is important in the range of 10 kHz to 1 MHz, while mesoscale loss dominates at the lower frequencies (<10 kHz) employed in seismology.

Results on soft and hard diffraction obtained by the CDF Collaboration in Run 1 of the Fermilab Tevatron {bar p}p collider are presented. Comparisons are made with theoretical predictions and with results from the DESY ep collider HERA.

None

Both shared memory and distributed memory models have advantages and shortcomings. Shared memory model is much easier to use but it ignores data locality/placement. Given the hierarchical nature of the memory subsystems in the modern computers this characteristic might have a negative impact on performance and scalability. Various techniques, such as code restructuring to increase data reuse and introducing blocking in data accesses, can address the problem and yield performance competitive with message passing[Singh], however at the cost of compromising the ease of use feature. Distributed memory models such as message passing or one-sided communication offer performance and scalability but they compromise the ease-of-use. In this context, the message-passing model is sometimes referred to as?assembly programming for the scientific computing?. The Global Arrays toolkit[GA1, GA2] attempts to offer the best features of both models. It implements a shared-memory programming model in which data locality is managed explicitly by the programmer. This management is achieved by explicit calls to functions that transfer data between a global address space (a distributed array) and local storage. In this respect, the GA model has similarities to the distributed shared-memory models that provide an explicit acquire/release protocol. However, the GA model acknowledges that remote data …

This report talks about Complex formation by the human Rad51B and Rad51C DNA repairproteins and their activities in vitro

Simulation of subsurface heterogeneity is important for modeling subsurface flow and transport processes. Previous studies have indicated that subsurface property variations can often be characterized by fractional Brownian motion (fBm) or (truncated) fractional Levy motion (fLm). Because Levy-stable distributions have many novel and often unfamiliar properties, studies on generating fLm distributions are rare in the literature. In this study, we generalize a relatively simple and computationally efficient successive random additions (SRA) algorithm, originally developed for generating Gaussian fractals, to simulate fLm distributions. We also propose an additional important step in response to continued observations that the traditional SRA algorithm often generates fractal distributions having poor scaling and correlation properties. Finally, the generalized and modified SRA algorithm is validated through numerical tests.

The Rare Isotope Accelerator (RIA) facility includes a driver linac for production of 400 kW CW heavy-ion beams. The initial acceleration of heavy-ions delivered from an ECR ion source can be effectively performed by a 57.5 MHz four-meter long RFQ. The principal specifications of the RFQ are: (1) formation of extremely low longitudinal emittance; (2) stable operation over a wide range of voltage for acceleration of various ion species needed for RIA operation; (3) simultaneous acceleration of two-charge states of uranium ions. CW operation of an accelerating structure leads to a number of requirements for the resonators such as high shunt impedance, efficient water cooling of all parts of the resonant cavity, mechanical stability together with precise alignment, reliable rf contacts, a stable operating mode and fine tuning of the resonant frequency during operation. To satisfy these requirements a new resonant structure has been developed. This paper discusses beam dynamics and electrodynamics design of the RFQ cavity, as well as, some aspects of the mechanical design of this low-frequency CW RFQ.

A new design for X band dielectric accelerator using a TE-TM mode converter has been proposed and studied. It first converts RF from TE to TM mode in a pure metal section, then a tapered transition section is used for high efficiency transmission to the dielectric accelerator section. Because there is no dielectrics near the RF coupler, this scheme has potential to overcome RF breakdown problems near the coupling holes in the dielectric based accelerators, as it happened in the older designs. A detailed design study shows that high conversion efficiency ({approx}100%) can be achieved for both single and dual coupling ports and it is less sensitive to machine errors than previous designs. Another advantage of this design is that it can be made to different modules thus greatly reduce the R&D cycles.

In order to examine more distant astronomical objects, with higher resolution, future space telescopes require objectives with significantly larger aperture than presently available. NASA has identified a progression in size from the 2.4m aperture objective currently used in the HUBBLE space telescope[l,2], to 25m and greater in order to observe, e.g., extra-solar planets. Since weight is a crucial factor for any object sent into space, the relative weight of large optics over a given area must be reduced[3]. The areal mass density of the primary mirror for the Hubble space telescope is {approx}200 kg/m{sup 2}. This is expected to be reduced to around 15 kg/m{sup 2} for the successor to Hubble--the next generation space telescope (NGST)[4]. For future very large aperture telescopes needed for extra-solar planet detection, the areal mass density must be reduced even further. For example, the areal mass density goal for the Gossamer space telescopes is < 1 kg/m{sup 2}. The production of lightweight focusing optics at >10m size is also an enabling technology for many other applications such as Earth observation, power beaming, and optical communications.

Various nondestructive evaluation (NDE) technologies are being developed to study the use of ceramic coatings on components in the hot-gas path of advanced low-emission gas-fired turbines. The types of ceramic coatings include thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). TBCs are under development for vanes, blades, and combustor liners to allow hotter gas-path temperatures, and EBCs are under development to reduce environmental damage to high-temperature components made of ceramic matrix composites. The NDE methods will be used to (a) provide data to assess the reliability of new coating application processes, (b) identify defective components that could cause unscheduled outages, (c) track growth rates of defects during component use in engines, and (d) allow rational judgment for replace/repair/re-use decisions regarding components. Advances in TBC application, both electron beam-physical vapor deposition (EB-PVD) and air plasma spraying (APS), are allowing higher temperatures in the hot-gas path. However, as TBCs become ''prime reliant,'' their condition at scheduled or unscheduled outages must be known. NDE methods are under development to assess the condition of the TBC for pre-spall conditions. EB-PVD test samples with up to 70 thermal cycles have been studied by a newly developed method involving polarized laser back-scatter NDE. Results suggest …

Using a recently developed, massively parallel molecular-dynamics (MD) code for the simulation of polycrystal plasticity, we analyze for the case of nanocrystalline Al the complex interplay among various dislocation and grain-boundary processes during low-temperature deformation. A unique aspect of this work, arising from our ability to deform to rather large plastic strains and to consider a rather large grain size, is the observation of deformation under very high grain-boundary and dislocation densities, i.e., in a deformation regime where they compete on an equal footing. We are thus able to identify the intra- and intergranular dislocation and grain-boundary processes responsible for the extensive deformation twinning observed in our simulations. This illustrates the ability of this type of simulations to capture novel atomic-level insights into the underlying deformation mechanisms not presently possible experimentally. smaller grain size, mobile dislocations must be nucleated from other sources, such as the GBs or grain junctions.

Recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source (SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR) at Los Alamos are presented in this paper. A refined model for the secondary emission process including the so called true secondary, rediffused and backscattered electrons has recently been included in the electron-cloud code.

None

Eyeglass is a very large aperture (25-100 meter) space telescope consisting of two distinct spacecraft, separated in space by several kilometers. A diffractive lens provides the telescope's large aperture, and a separate, much smaller, space telescope serves as its mobile eyepiece. Use of a transmissive diffractive lens solves two basic problems associated with very large aperture space telescopes; it is inherently fieldable (lightweight and flat, hence packagable and deployable) and virtually eliminates the traditional, very tight, surface shape tolerances faced by reflecting apertures. The potential drawback to use of a diffractive primary (very narrow spectral bandwidth) is eliminated by corrective optics in the telescope's eyepiece. The Eyeglass can provide diffraction-limited imaging with either single-band, multiband, or continuous spectral coverage. Broadband diffractive telescopes have been built at LLNL and have demonstrated diffraction-limited performance over a 40% spectral bandwidth (0.48-0.72 {micro}m). As one approach to package a large aperture for launch, a foldable lens has been built and demonstrated. A 75 cm aperture diffractive lens was constructed from 6 panels of 1 m thick silica; it achieved diffraction-limited performance both before and after folding. This multiple panel, folding lens, approach is currently being scaled-up at LLNL. We are building a 5 meter …

None

The Nuclear Science Community in the Unites States has unanimously concluded that developments in both nuclear science and its supporting technologies make building a world-leading Rare-Isotope Accelerator (RIA) facility for production of radioactive beams the top priority. The RIA development effort involves several US Laboratories (ANL, JLAB, LBNL, MSU, ORNL). The RIA Facility includes a CW 1.4 GeV driver linac and a 100 MV post-accelerator both based on superconducting (SC) cavities operating at frequencies from 48 MHz to 805 MHz. An initial acceleration in both linacs is provided by room temperature RFQs. The driver linac is designed for acceleration of any ion species; from protons up to 900 MeV to uranium up to 400 MeV/u. The novel feature of the driver linac is an acceleration of multiple charge-state heavy-ion beams in order to achieve 400 kW beam power. Basic design concepts of the driver linac are given. Several new conceptual solutions in beam dynamics, room temperature and SC accelerating structures for heavy ion accelerator applications are discussed.

This work focuses on the investigation of the distribution of contaminants in individual sediment particles from the New York/New Jersey Harbor. Knowledge of the spatial distribution of the contaminants within the particles is needed to enable (1) more sophisticated approaches to the understanding of the fate and transport of the contaminants in the environment and (2) more refined methods for cleaning the sediments. The size of the investigated particles ranges from 30-80 microns. Due to the low concentration of the elements of interest and the microscopic size of the environmental particles in these measurements, the small size and high intensity of the analyzing X-ray beam was critical. The high photon flux at the ESRF Microfocus beam line (ID13) was used as the basis for fluorescence tomography to investigate whether the inorganic compounds are taken upon the surface organic coating or whether they are distributed through the volume of the grains being analyzed. The experiments were done using a 13 keV monochromatic beam of approximately 2 {micro}m in size having an intensity of 10{sup 10} ph/s, allowing absolute detection limits on the 0.04-1 fg level for Ti, Cr, Mn, Fe, Ni, and Zn.

High resolution X-ray Photoelectron Spectroscopy (XPS) was used to analyze thin layers of germanium oxide grown on germanium substrates under various conditions. The results reveal the presence of high density of electron states located at the oxide/germanium interface that lead to the energy band bending. The surface of native oxide layers and that of thin oxide layer grown under dry oxygen correspond to GeO2 composition. Under Ar etching, lower oxidation states were revealed. Short in-situ heat treatment at T=400 degrees C under ultra high vacuum leads to the removal of the oxide layer. In addition, the analysis of the layer grown at T=380 degrees C under dry oxygen suggest that carbides form at the oxide/substrate interface.

None

The effect of pre-irradiation heat treatments on thermal non-equilibrium grain boundary segregation (TNES) and subsequent radiation-induced grain boundary segregation (RIS) is studied in a series of model austenitic stainless steels. The alloys used for this study are based on AISI 316 stainless steel and have the following nominal compositions: Fe-16Cr-13Ni-1.25Mn (base 316), Fe-16Cr-13Ni-1.25Mn-2.0Mo (316 + Mo) and Fe-16Cr-13Ni-1.25Mn-2.0Mo-0.07P (316 + Mo + P). Samples were heat treated at temperatures ranging from 1100 to 1300 C and cooled at 4 different rates (salt brine quench, water quench, air cool and furnace cool) to evaluate the effect of annealing temperature and quench rate on TNES. The alloys were than processed with the treatment (temperature and cooling rate) that resulted in the maximum Cr enrichment. Alloys with and without the heat treatment to enrich the grain boundaries with Cr were characterized following irradiation to 1 dpa at 400 C with high-energy protons in order to understand the influence of alloying additions and pre-irradiation grain boundary chemistry on irradiation-induced elemental enrichment and depletion profiles. Various mechanistic models will be examined to explain the observed behavior.

A well-adapted spectrograph concept has been developed for the SNAP (SuperNova/Acceleration Probe) experiment. The goal is to ensure proper identification of Type Ia supernovae and to standardize the magnitude of each candidate by determining explosion parameters. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented in this paper. The spectrograph concept is optimized to have very high efficiency and low spectral resolution (R {approx} 100), constant through the wavelength range (0.35-1.7{micro}m), adapted to the scientific goals of the mission.

Recent analyses by the CDF and D0 Collaborations of jet data produced in p{bar p} collisions at the Fermilab Tevatron Collider are presented. These include new studies of the inclusive jet production cross section, a measurement of the strong coupling constant, the first measurement of subjet multiplicity of quark and gluon jets, examination of ratios of multijet cross sections and their implications for choice of renormalization scale, and a study of charged jet evolution and energy flow in the underlying event. The results are compared to theoretical predictions.