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We study inclusive heavy quark and exclusive heavy quark pair production in pp, pA and AA interactions. Intrinsic transverse momentum is introduced in pp interactions. Nuclear effects, limited to k{sub T} broadening and nuclear shadowing, are introduced in pA and AA interactions. The nuclear dependence is studied over a range of energies, both in fixed target and collider setups.

An electron-nucleus (e-A) collider with center-of-mass energy in excess of 50 GeV per electron-nucleon collision will allow the physics community to obtain unprecedented new knowledge of the partonic structure of nuclei. If reliable information is to be extracted on these partonic densities, it is essential to realize that with our current level of understanding of QCD, momentum transfers to the struck partons greater than 1 GeV/c are necessary. This requirement puts a priority on high center-of-mass energy if partonic densities are to be measured over a wide range. Comparing the partonic structure of the free nucleon to that of bound nucleons and measuring the systematic changes in that structure as a function of nucleon number (A) will provide deeper insight into the origins and dynamics of nuclear binding. In addition, e-A collisions will allow the exploration of partonic densities appreciably higher than is accessible in e-p collisions. An e-A collider will allow one to measure the gluonic structure functions of nuclei down to x {approx} 10{sup -3}, information valuable in its own right and essential to a quantitative understanding of highly relativistic A-A collisions. The time-space evolution of partons can only be investigated by studying the modifications of hard collisions …

A technique to convert reflection elastic recoil detection analysis spectra to depth profiles, the channel-depth conversion, was introduced by Verda, et al [1]. But the channel-depth conversion does not correct for energy spread, the unwanted broadening in the energy of the spectra, which can lead to errors in depth profiling. A work in progress introduces a technique that corrects for energy spread in elastic recoil detection analysis spectra, the energy spread correction [2]. Together, the energy spread correction and the channel-depth conversion comprise an accurate and convenient hydrogen depth profiling method.

Selenocarbonyls that are housed in a chiral environment have been found to play a pivotal role aldol reactions. We have found that, in general,, the aldol reaction affords the non-Evans aldol syn products. However, the use of glycolate donors with glycoaldehydes, under proper conditions, gave rise to predominately the anti aldol.

We present an adaptive control loop that synthesizes fs-pulses that are self-correcting for higher order nonlinear effects when launched in a conventional single-mode fiber, nearly preserving the initial (t{approx}200 fs) pulse duration.

The Accelerator Driven Test Facility (ADTF) is being developed as a reactor concepts test bed for transmutation of nuclear waste. A 13.3 mA continuous-wave (CW) proton beam will be accelerated to 600 MeV and impinged on a spallation target. The subsequent neutron shower is used to create a nuclear reaction within a subcritical assembly of waste material that reduces the waste half-life from the order of 10{sup 5} years to 10{sup 2} years. Additionally, significant energy is produced that can be used to generate electrical power. The ADTF proton accelerator consists of room-temperature (RT) structures that accelerate the beam to 6.7-MeV and superconducting (SC) elements that boost the beam's energy to 600-MeV. Traditional SC elliptical cavities experience structural difficulties at low energies due to their geometry. Therefore, stiff-structured SC spoke cavities have been adopted for the energy range between 6.7 and 109 MeV. Elliptical cavities are used at the higher energies. This paper describes a multi-spoke-cavity cryomodule concept for ADTF.

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We present here computer modeling efforts to describe the time-dependent pressurization and gas-phase mole fractions inside sealed canisters containing actinide materials packaged with small (0.12 - 0.5 wt. %) amounts of water. The model is run using Chemkin software, and the chemical reaction mechanism includes gas generation due to radiolysis of adsorbed water, interfacial chemical reactions, and adsorption/desorption kinetics of water on PuO2 materials. The ultimate goal is to provide a verifiable computer model that can be used to predict problematic gas generation in storage forms and assure design criteria for short-term storage and transportation of less than well-characterized (with respect to gas generation) material classes. Our initial efforts are intended to assess pressurization and gas-phase mole fractions using well-defined 3013 container test cases. We have modeled gas generation on PuO2 with water loading up to 0.5 wt. %, at 300 and 525 K, for time frames of 3 years. Estimates of the initial H2 generation rates were determined using RadCalc and employed in the Chemkin model to assess time- and coverage-dependent system behavior. Results indicate that canister pressurization due to radiolysis is a relatively slow process, with pressure increases at 300 K of approximately 1.5 atm. for 5000 g …

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The Albany Research Center of the U.S. Department of Energy has been investigating a means to form useful wrought products by direct and continuous casting of titanium bars using cold-wall induction melting rather than current batch practices such as vacuum arc remelting. Continuous ingots produced by cold-wall induction melting, utilizing a bottomless water-cooled copper crucible, without slag (CaF2) additions had minor defects in the surface such as ''hot tears''. Slag additions as low as 0.5 weight percent were used to improve the surface finish. Therefore, a slag melted experimental Ti-6Al-4V alloy ingot was compared to a commercial Ti-6Al-4V alloy ingot in the areas of physical, chemical, mechanical, and corrosion attributes to address the question, ''Are any detrimental effects caused by slag addition''?

Knowledge of aerosol chemical composition is key to understanding a number of properties of ambient aerosol particles including sources, size/number distribution, chemical evolution, optical properties and human health effects. Although filter based techniques have been widely used to determine aerosol chemical constituents, they generally cannot provide sufficiently fast time resolution needed to investigate sources and chemical evolution that effect aerosol chemical, size and number changes. In order to gain an ability to describe and predict the life cycles of ambient aerosols as a basis for ambient air quality control, fast and sensitive determination of the aerosol chemical composition must be made available. To help to achieve this goal, we deployed a newly developed technique, referred to as PILS (particle-into-liquid-sampler), on the DOE G1 aircraft during the 2000 Texas Air Quality Study (TexAQS 2000) to characterize the major ionic species of aerosol particles with aerodynamic size smaller than 2.5 {micro}m (PM 2.5). The results obtained are examined in the context of other simultaneously collected data for insights into the measurement capability of the PILS system.

Knowledge of aerosol chemical composition is key to understanding a number of properties of ambient aerosol particles including sources, size/number distribution, chemical evolution, optical properties and human health effects. Although filter based techniques have been widely used to determine aerosol chemical constituents, they generally cannot provide sufficiently fast time resolution needed to investigate sources and chemical evolution that effect aerosol chemical, size and number changes. In order to gain an ability to describe and predict the life cycles of ambient aerosols as a basis for ambient air quality control, fast and sensitive determination of the aerosol chemical composition must be made available. To help to achieve this goal, we deployed a newly developed technique, referred to as PILS (particle-into-liquid-sampler), on the DOE G1 aircraft during the 2000 Texas Air Quality Study (TexAQS 2000) to characterize the major ionic species of aerosol particles with aerodynamic size smaller than 2.5 {micro}m (PM 2.5). The results obtained are examined in the context of other simultaneously collected data for insights into the measurement capability of the PILS system.

A hybrid particle/continuum algorithm is formulated for Fickian diffusion in the fluctuating hydrodynamic limit. The particles are taken as independent random walkers; the fluctuating diffusion equation is solved by finite differences with deterministic and white-noise fluxes. At the interface between the particle and continuum computations the coupling is by flux matching, giving exact mass conservation. This methodology is an extension of Adaptive Mesh and Algorithm Refinement to stochastic partial differential equations. A variety of numerical experiments were performed for both steady and time-dependent scenarios. In all cases the mean and variance of density are captured correctly by the stochastic hybrid algorithm. For a non-stochastic version (i.e., using only deterministic continuum fluxes) the mean density is correct, but the variance is reduced except within the particle region, far from the interface. Extensions of the methodology to fluid mechanics applications are discussed.

Adaptive mesh refinement is complicated by both the algorithms and the dynamic nature of the computations. In parallel the complexity of getting good performance is dependent upon the architecture and the application. Most attempts to address the complexity of AMR have lead to the development of library solutions, most have developed object-oriented libraries or frameworks. All attempts to date have made numerous and sometimes conflicting assumptions which make the evaluation of performance of AMR across different applications and architectures difficult or impracticable. The evaluation of different approaches can alternatively be accomplished through simulation of the different AMR processes. In this paper we outline our research work to simulate the processing of adaptive mesh refinement grids using a distributed array class library (P++). This paper presents a combined analytic and empirical approach, since details of the algorithms can be readily predicted (separated into specific phases), while the performance associated with the dynamic behavior must be studied empirically. The result, AMRSim, provides a simple way to develop bounds on the expected performance of AMR calculations subject to constraints given by the algorithms, frameworks, and architecture.

Enhancements have been made to the log-ratio analog front-end electronics based on the Analog Devices 8307 logarithmic amplifier as used on the LEDA accelerator. The dynamic range of greater than 85 dB, has been extended to nearly the full capability of the AD8307 from the previous design of approximately 65 dB through the addition of a 350 MHz band-pass filter, careful use of ground and power plane placement, signal routing, and power supply bypassing. Additionally, selection of high-isolation RF switches (55dB) has been an integral part of a new calibration technique, which is fully described in another paper submitted to this conference. Provision has also been made for insertion of a first-stage low-noise amplifier for using the circuit under low-signal conditions.

Developing a predictive model for cook-off is a difficult task. Recent experiments with PBX 9501 have shown that under certain heating and confinement conditions it is possible to generate large regions of almost uniform temperature in an explosive. Such regions react violently in a coherent fashion and may have the potential to produce unusually symmetric detonation waves in certain geometries. These results were unexpected before the experiments and have generated considerable additional activity both experimentally and in model building. At this time, there is no unambiguous explanation for the observed behavior, and therefore, there is a considerable number of fledgling models in existence. These models suggest varying and possibly contradictory mechanisms to explain the thermal profiles and wave behavior data. In this paper, we present an approach to model development for cook-off of PBX 9501 based on logic models called process trees. Process trees are well-suited to the task of describing causal sequences and delineating alternative descriptions of observed phenomenology. Therefore, they provide a valuable basis for constructing physical models and integrating them.

The Zeus experiments have been designed to test the adequacy of {sup 235}U cross sections in the intermediate energy range. The first Zeus experiment achieved initial criticality on April 26, 1999 with 10 HEU platters and 79 platters of graphite. The second experiment reached a critical condition on October 24, 2000, with 9 HEU platters and 54 platters of graphite. The first experiment, which has been described and analyzed previously, had a C/{sup 235}U ratio of approximately 52:1. The corresponding ratio for the second experiment was approximately 40:1. This summary describes the analysis of the second Zeus critical experiment.

CCL cavities are figures of revolution about the beam axis. An automated tuning program sets up the geometry for a symmetric accelerating cavity and runs SUPERFISH repetitively, varying the geometry to tune each cavity to the desired frequency for the electromagnetic fields. SUPERFISH solves Maxwell's equations in 2-D. A large portion of the RF power (60-80%) applied to accelerate protons is a waste heat deposited on the inside of the copper cavity. This waste heat is removed most efficiently with water circulating through cooling passages. The waste heat needs to be removed in order to minimize thermal deformations and with it control the resonance of the cavities. A slot between the main cavity and coupled cavity receives additional heating that is not captured in the 2-D analysis. This heating causes deformation of the region and with it frequency shift. This paper covers the estimation of the slot heating and three-dimensional thermal and structural analysis of the CCL cavity.

Cylinder test data is reported for commercially available prilled ANFO (ammonium-nitrate/fuel-oil) at 0.93 ,g/cc density and ambient temperature. The tests were four-inch inner diameter, with wall-thickness and length scaled from the standard one-inch test (0.4 inch and 48 inch, respectively). The wall expansion was measured with a rotating mirror streak camera and the velocity was measured by fine-wire pin switches, in the standard manner. The wall expansion trajectory is much smoother than for conventional explosives, which show a pronounced jump-off with subs uent ring-up. This observation is consistent with a broadened detohation shock in the granular bed. ?he data is analyzed for equation-of-state information and JWL parameters are given.

The effect of MnS inclusion orientation on damage evolution and fracture toughness in HYlOO steel is investigated in the context of anisotropic damage modeling at the continuum level. Experimental notched-bar data sets are analyzed and modeled using finite element calculations with constitutive behavior that assumes isotropic elastoplastic behavior in conjunction with anisotropic damage.

This Recommendation/International Standard uses a transformation of tile components. In this Annex and all of its sub clauses, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate.

Hydrodynamic gas-lubricated foil bearings are ideal for machinery that operates at high speed or in extreme-temperature environments. As motors and generators run at higher speeds with more torque capacity, the need for commonly available, robust, high-speed, low-loss foil bearings is clear. This paper presents an application example of the successful replacement of a tape-type bearing for a bump-type bearing in a helium turbocompressor. Both bearing types are described, as are the steps involved in design and fabrication of the bump bearing, and results of comparison tests between the original and replacement bearings. Methods to analyze bump-type foil bearings with commercially available software are reviewed to further emphasize the inherent simplicity of these bearings. By providing the engineering community with the understanding needed to successfully apply foil bearings, the authors hope that the benefits and true potential of this technology will finally be realized.