Some scoping experiments were performed to evaluate fuel performance in a lithium heat pipe reactor operating at a nominal 1500K heat pipe temperature. Fuel-coolant and fuel-coolant-clad relationships showed that once a failed heat pipe occurs temperatures can rise high enough so that large concentrations of uranium can be transported by the vapor phase. Upon condensation this uranium would be capable of penetrating heat pipes adjacent to the failed pipe. The potential for propagation of failure exists with UO/sub 2/ and a lithium heat pipe. Changing the composition of the metal of the heat pipe would have only a second order effect on the kinetics of the failure mechanism. Uranium carbide and nitride were considered as potential fuels which are nonreactive in a lithium environment. At high temperatures the nitride would be favored because of its better compatibility with potential cladding materials. Compositions of UN with small additions of YN appear to offer very attractive properties for a compact high temperature high power density reactor.

An apparatus utilizing filter-fluorescer combinations is provided to measure short bursts of high fluence x-rays above 120 keV energy, where there are no practical absorption edges available for conventional filter-fluorescer techniques. The absorption edge of the prefilter is chosen to be less than that of the fluorescer, i.e., E/sub PRF/ < E/sub F/, contrary to the prior art technique E/sub PRF/ > E/sub F/. In this way, the response function is virtually zero between E/sub PRF/ and E/sub F/ and well defined and enhanced in an energy band of less than 1000 keV above the 120 keV energy.

A double arm lead-glass lead-scintillator calorimeter system was used to search for narrow states, such as the eta/sub c/, produced in the exclusive reactions ..pi../sup -/p ..--&gt;.. ..gamma gamma..n, ..pi../sup -/p ..--&gt;.. ..pi../sup 0/..gamma..n, and ..pi../sup -/p ..--&gt;.. ..pi../sup 0/..pi../sup 0/n at 13 GeV/c. A 90% c.l. upper limit sigma.BR &lt; 260 pb was found for ..gamma gamma.. states with masses from 2.6 to 3.1 GeV/c/sup 2/. Corresponding limits on narrow ..pi../sup 0/..gamma.. and ..pi../sup 0/..pi../sup 0/ states are also given.

A cylindrical eddy current tube testing probe is disclosed. Current flow in dual electromagnetic coils separated by an eddy current sensing coil is so directed that magnetic fields of the electromagnet coils have components extending in opposite directions axially of the tested tube and components extending radially of the tube which add in the region of the eddy current sensing coil.

The initial research and development of a system that uses high pressure helium gas to pressurize vessels over a wide range of pressurization rates, vessel volumes, and maximum test pressures are described. A method of controlling the mass flow rate in a test vessel was developed by using the pressure difference across a capillary tube. The mass flow rate is related to the pressurization rate through a real gas equation of state. The resulting mass flow equation is then used in a control algorithm. Plots of two typical pressurization tests run on a manually operated system are included.

The LOFT pressurizer spray and surge line piping was analyzed for a 450/sup 0/F step change in fluid temperature. This transient was chosen to conservatively represent several pressurizer operating transients that had not previously been analyzed. These include temperature transients resulting from a 300/sup 0/F ..delta..T between pressurizer temperature and cold leg temperature, injection of a cooled (70/sup 0/F) slug of stagnant fluid into the hot (540/sup 0/F) spray line piping, and inflow of 100/sup 0/F primary coolant system water into the hot (480/sup 0/F) surge line piping.

The multiblade slurry technique capable of slicing 10 cm ingot into wafers 0.25 mm thick with only 0.20 mm kerf loss and 98% yield has been demonstrated. The total silicon requirement represents an ingot to sheet conversion of 0.95 m/sup 2//kg. Full production slicing tests have demonstrated the cost of MS slicing to contribute $40 to $50/m/sup 2/, with ''best effort'' estimates for today's configuration to be $30 to $35/m/sup 2/. By reducing material cost, and increasing the specific capacity of a saw to slice 900 wafers simultaneously, the long-term cost of MS slicing is estimated to be less than $10/m/sup 2/. The conversion of ingot to sheet is shown to be the most valuable contribution of slicing technology. At today's ingot costs, and with the thin wafer, low kerf loss slicing techniques demonstrated, the silicon material represents 5 to 10 times the cost of the wafering process in finished silicon wafers. Increasing the number of blades used in MS slicing from 100 to 150 to 225 to 300 has resulted in a reduction of yield to 33 to 70% for thin slicing, or an increase in wafer thickness to 0.30 mm slices. The limitation is intrinsic misalignment of multiple …

The coupling of energetic metallic multilayers (a.k.a. flash metal) with energetic sol-gel synthesis and processing is an entirely new approach to forming energetic devices for several DoD and DOE needs. They are also practical and commercially viable manufacturing techniques. Improved occupational safety and health, performance, reliability, reproducibility, and environmentally acceptable processing can be achieved using these methodologies and materials. The development and fielding of this technology will enhance mission readiness and reduce the costs, environmental risks and the necessity of resolving environmental concerns related to maintaining military readiness while simultaneously enhancing safety and health. Without sacrificing current performance, we will formulate new impact initiated device (IID) compositions to replace materials from the current composition that pose significant environmental, health, and safety problems associated with functions such as synthesis, material receipt, storage, handling, processing into the composition, reaction products from testing, and safe disposal. To do this, we will advance the use of nanocomposite preparation via the use of multilayer flash metal and sol-gel technologies and apply it to new small IIDs. This work will also serve to demonstrate that these technologies and resultant materials are relevant and practical to a variety of energetic needs of DoD and DOE. The goal …

The CALPHAD approach is applied to kinetic studies of phase transformations and aging of prototypes of Ni-Cr-Mo-based alloys selected for waste disposal canisters in the Yucca Mountain Project (YMP). Based on a previous study on alloy stability for several candidate alloys, the thermodynamic driving forces together with a newly developed mobility database have been used to analyze diffusion-controlled transformations in these Ni-based alloys. Results on precipitation of the Ni{sub 2}Cr-ordered phase in Ni-Cr and Ni-Cr-Mo alloys, and of the complex P- and {delta}-phases in a surrogate of Alloy 22 are presented, and the output from the modeling are compared with experimental data on aging.

The recent discoveries of nonmolecular phases of simple molecular solids [1,2] demonstrate the proof-of-the-principles for producing exotic phases by application of high pressure. Modern advances in theoretical and computational methodologies now make possible to explain or even predict novel structures and properties in a relatively wide range of length scales on the basis of thermodynamic stability [3]. Equally important in materials research is the recent developments in advanced x-ray and laser diagnostics that enable in-situ observations at the formidable pressure-temperature conditions [4]. Having benefited by all these developments, we discuss the first principle of the pressure-induced chemistry, 'Mbar Chemistry', with a few examples that may have important implications in materials research.

P. fluorescens PfO-1 is a soil bacterium isolated by this laboratory from sandy loam soil (4). Because of the importance of adhesion for persistence in natural environments, we utilized adherence to sand as an assay to screen a library of PfO-1 mutants for defects in adhesion. Three adhesion defective mutants, PfO-5, PfO-10, and PfO-15 were recovered. PfO-5 and PfO-10 had different insertions in the same gene, which we called adnA, and also showed motility defects (3). PfO-15 was motile, but was hyper-flagellated. The insertion was in a different gene, adnB, which shows similarity to mot genes involved in flagella functions (Strain and Levy, unpublished). These early studies demonstrated the important but separable requirements for flagella and motility in adherence. In a field study, the adnA mutant PfO-5 was less able to persist than the wildtype PfO-1 and did not spread as fast or as far from the point of inoculation as did PfO-1 (7), linking adhesion and soil fitness. DNA sequencing revealed that AdnA shares 82% identity with the flagella regulator FleQ from P. aeruginosa (3). FleQ is required for adhesion of P. aeruginosa to respiratory mucin, which is important for pathogenesis (1, 2). Using a gene fusion approach, seven …

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius …

Rare charmless hadronic B decays are a good testing ground for QCD. In this paper we describe a selection of new measurements made by the BABAR and BELLE collaborations.

The trace anomaly of gluodynamics encodes the breakdown of classical scale invariance due to interactions around the deconfinement phase transition. While it is expected that at high temperatures perturbation theory becomes applicable we show that current lattice calculations are far from the perturbative regime and are dominated instead by inverse even power corrections in the temperature, while the total perturbative contribution is estimated to be extremely small and compatible with zero within error bars. We provide an interpretation in terms of dimension-two gluon condensate of the dimensionally reduced theory which value agrees with a similar analysis of power corrections from available lattice data for the renormalized Polyakov loop and the heavy quark-antiquark free energy in the deconfined phase of QCD [1,2].

Depleted uranium hexafluoride (UF{sub 6}) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF{sub 6} Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF{sub 6} and the cylinders containing it. This report documents activities that address UF{sub 6} Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to …

SABER, the South Arc Beam Experimental Region, is a proposed new beam line facility designed to replace the Final Focus Test Beam at SLAC. In this paper, we outline the optical design features and beam parameters now envisioned for SABER. A magnetic chicane to compress positron bunches for SABER and a bypass line that could transport electrons or positrons from the two-thirds point of the linac to SABER, bypassing the LCLS systems, are also discussed.

CTCP, an innovative TCP congestion control algorithm developed by Microsoft, is evaluated and compared to HSTCP and StandardTCP. Tests were performed on the production Internet from Stanford Linear Accelerator Center (SLAC) to various geographically located hosts to give a broad overview of the performances. We find that certain issues were apparent during testing (not directly related to the congestion control algorithms) which may skew results. With this in mind, we find that CTCP performed similarly to HSTCP across a multitude of different network environments. However, to improve the fairness and to reduce the impact of CTCP upon existing StandardTCP traffic, two areas of further research were investigated. Algorithmic additions to CTCP for burst control to reduce the aggressiveness of its cwnd increments demonstrated beneficial improvements in both fairness and throughput over the original CTCP algorithm. Similarly, {gamma} auto-tuning algorithms were investigated to dynamically adapt CTCP flows to their network conditions for optimal performance. While the effects of these auto-tuning algorithms when used in addition to burst control showed little to no benefit to fairness nor throughput for the limited number of network paths tested, one of the auto-tuning algorithms performed such that there was negligible impact upon StandardTCP. With these …

The intended purpose of the multiscale thermohydrologic model (MSTHM) is to predict the possible range of thermal-hydrologic conditions, resulting from uncertainty and variability, in the repository emplacement drifts, including the invert, and in the adjoining host rock for the repository at Yucca Mountain. The goal of the MSTHM is to predict a reasonable range of possible thermal-hydrologic conditions within the emplacement drift. To be reasonable, this range includes the influence of waste-package-to-waste-package heat output variability relevant to the license application design, as well as the influence of uncertainty and variability in the geologic and hydrologic conditions relevant to predicting the thermal-hydrologic response in emplacement drifts. This goal is quite different from the goal of a model to predict a single expected thermal-hydrologic response. As a result, the development and validation of the MSTHM and the associated analyses using this model are focused on the goal of predicting a reasonable range of thermal-hydrologic conditions resulting from parametric uncertainty and waste-package-to-waste-package heat-output variability. Thermal-hydrologic conditions within emplacement drifts depend primarily on thermal-hydrologic conditions in the host rock at the drift wall and on the temperature difference between the drift wall and the drip-shield and waste-package surfaces. Thus, the ability to predict a …

An international collaboration is currently working on the construction and design of an asymmetric B Factory at the Stanford Linear Accelerator Center that will be ready to collect data in 1999. The main physics motivation for such a facility is to test the description and mechanism of CP violation in the Standard Model of particle physics and provide insight into the question of why more matter than antimatter is observed in the universe today. In particular, this experiment will measure CP violation in the decay of B mesons. In the early stages of this effort, the Canadian contingent proposed to build the central tracking chamber for the BaBar detector. Presently, a prototype drift chamber is in operation and studies are being performed to test some of the unique features of drift chamber design dictated by the conditions of the experiment. Using cosmic muons, it is possible to study tracking and pattern recognition in the prototype chamber, and therefore calculate the efficiency and spatial resolution of the prototype chamber cells. These performance features will be used to test whether or not the helium-based gas mixtures proposed for the BaBar drift chamber are a viable alternative to the more traditional argon-based gases.

The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R&amp;D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics.

The growth rates of the longitudinal higher-order impedance-driven beam modes have greatly increased since the initial PEP-II design and commissioning. This increase is attributed to the addition of 6 1.2MW RF stations with 8 accelerating cavities in the HER and 2 1.2MW RF stations with 4 accelerating cavities in the LER, which allowed operations at twice the design current and almost four times the luminosity. As a result, the damping requirements for the longitudinal feedback have greatly increased since the design, and the feedback filters and control schemes have evolved during PEP-II operations. In this paper, growth and damping rate data for the higher-order mode (HOM) driven coupled-bunch modes are presented from various PEP-II runs and are compared with historical estimates during commissioning. The effect of noise in the feedback processing channel is also studied. Both the stability and performance limits of the system are analyzed.

The increased need to manage California?s electricity grid in real time is a result of the ongoing transition from a system operated by vertically-integrated utilities serving native loads to one operated by an independent system operator supporting competitive energy markets. During this transition period, the traditional approach to reliability management -- construction of new transmission lines -- has not been pursued due to unresolved issues related to the financing and recovery of transmission project costs. In the absence of investments in new transmission infrastructure, the best strategy for managing reliability is to equip system operators with better real-time information about actual operating margins so that they can better understand and manage the risk of operating closer to the edge. A companion strategy is to address known deficiencies in offline modeling tools that are needed to ground the use of improved real-time tools. This project: (1) developed and conducted first-ever demonstrations of two prototype real-time software tools for voltage security assessment and phasor monitoring; and (2) prepared a scoping study on improving load and generator response models. Additional funding through two separate subsequent work authorizations has already been provided to build upon the work initiated in this project.

During 2007 and 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was designed and fabricated for use in double-shell tank 241-AN-102. The system was successfully installed in the tank on May 1, 2008. The 241-AN-102 MPCMS consists of one 'fixed' in-tank probe containing primary and secondary reference electrodes, tank material electrodes, Electrical Resistance (ER) sensors, and stressed and unstressed corrosion coupons. In addition to the fixed probe, the 241-AN-102 MPCMS also contains four standalone coupon racks, or 'removable' probes. Each rack contains stressed and unstressed coupons made of American Society of Testing and Materials A537 CL1 steel, heat-treated to closely match the chemical and mechanical characteristics of the 241-AN-102 tank wall. These coupon racks can be removed periodically to facilitate examination of the attached coupons for corrosion damage. Along the way to successful system deployment and operation, the system design, fabrication, and testing activities presented a number of challenges. This document discusses these challenges and lessons learned, which when applied to future efforts, should improve overall project efficiency.

The BaBar high energy physics experiment will be in operation at the PEP-II asymmetric e{sup +}e{sup -} collider in Spring 1999. The primary purpose of the experiment is the investigation of CP violation in the neutral B meson system. The electromagnetic calorimeter forms a central part of the experiment and new techniques are employed in data acquisition and reconstruction software to maximize the capability of this device. The use of a matched digital filter in the feature extraction in the front end electronics is presented. The performance of the filter in the presence of the expected high levels of soft photon background from the machine is evaluated. The high luminosity of the PEP-II machine and the demands on the precision of the calorimeter require reliable software that allows for increased physics capability. BaBar has selected C++ as its primary programming language and object oriented analysis and design as its coding paradigm. The application of this technology to the reconstruction software for the calorimeter is presented. The design of the systems for clustering, cluster division, track matching, particle identification and global calibration is discussed with emphasis on the provisions in the design for increased physics capability as levels of understanding of …