Yrast excitations around {sup 132}Sn: The two and three valence- proton N = 82 isotones {sup 134}Te and {sup 135}I (open access)

Yrast excitations around {sup 132}Sn: The two and three valence- proton N = 82 isotones {sup 134}Te and {sup 135}I

Large multidetector {gamma}-ray arrays, which can separate the prompt {gamma}-ray cascades within a single fission product nucleus (of moderate yield) from the bulk of prompt {gamma}-rays, has now opened new prospects for studies of yrast excitations in {sup 132}Sn and the few valence particle nuclei around it. Measurements were performed at Eurogam II using a {sup 248}Cm source. This paper features the results for the two and three valence proton N=82 isotones {sup 134}Te and {sup 135}I which exhibit simple clearcut excitation modes, resembling {sup 210}Po and {sup 211}At, their well studied N=126 counterparts in the {sup 208}Pb region. A search was made for new {sup 135}I transitions by setting a single coincidence gate on 1134 keV {gamma}-rays; strong 288, 572, 690, 725, 1661, 1695, and 2247 keV coincident {gamma}-rays were identified as {sup 135}I {gamma}-rays. In summary, yrast excitations to above 5.5 MeV excitation energy in the 2- and 3-proton nuclei {sup 134}Te and {sup 135}I have been established and interpreted with help of shell model calculations using empirical nucleon-nucleon interactions. This opens possibilities for exploring simple excitation modes in the {sup 132}Sn region under conditions comparable with but not identical to those in the well-studied {sup 208}Pb region.
Date: November 1996
Creator: Daly, P. J.; Zhang, C. T. & Bhattacharyya, P.
System: The UNT Digital Library
Electroweak physics results from the Tevatron (open access)

Electroweak physics results from the Tevatron

An overview of recent electroweak physics results from the Tevatron is given. Properties of the W{sup {+-}} and Z{sup 0} gauge bosons using final states containing electrons and muons based on large integrated luminosities are presented. In particular, measurements of the W{sup {+-}} and Z{sup 0} production cross sections, the W-charge asymmetry and the measurement of the W-mass are summarized. Gauge boson self interactions are measured by studying gauge boson pair production and Emits on anomalous gauge boson couplings are discussed.
Date: November 1, 1996
Creator: Demarteau, M.
System: The UNT Digital Library
Numerical predictions of dry oxidation of iron and low-carbon steel at moderately elevated temperatures (open access)

Numerical predictions of dry oxidation of iron and low-carbon steel at moderately elevated temperatures

Wrought and cast low-carbon steel are candidate materials for the thick (e.g. 10 cm) outer barrier of nuclear waste packages being considered for use in the potential geological repository at Yucca Mountain. Dry oxidation is possible at the moderately elevated temperatures expected at the container surface (323-533 K or 50-260 C). Numerical predictions of dry oxidation damage were made based on experimental data for iron and low-carbon steel and parabolic oxidation theory. The Forward Euler method was implemented to integrate the parabolic rate law for arbitrary, complex temperature histories. Assuming growth of a defect-free, adherent oxide, the surface penetration of a low-carbon steel barrier following 5000 years of exposure to a severe, but repository-relevant, temperature history is predicted to be only about 0.127 mm, less than 0.13% of the expected container thickness of 10 cm. Allowing the oxide to spall upon reaching a critical thickness increases the predicted metal penetration values, but degradation is still computed to be negligible. Thus, dry oxidation is not expected to significantly degrade the performance of thick, corrosion allowance barriers constructed of low-carbon steel.
Date: November 1, 1996
Creator: Henshall, G.A.
System: The UNT Digital Library
Sandia/SEMATECH Contamination Free Manufacturing Research Center, novel sensor development activities for enhanced process control (open access)

Sandia/SEMATECH Contamination Free Manufacturing Research Center, novel sensor development activities for enhanced process control

The Sandia/SEMATECH Contamination Free Manufacturing Research Center (CFMRC) was founded in 1992 with the goal of providing research and development support to the U.S. semiconductor industry in the area of defect reduction in manufacturing equipment and processes. The program encompasses topics in equipment/process contamination modeling, advanced wafer cleaning, water use reduction, organic contamination, wafer- map defect data analysis and contamination sensor development. The Contamination Sensor development activity focuses on producing advanced tools for the semiconductor industry by development and commercialization of in-line cost-effective sensors for measurement of contaminants in critical process tools. There are three phases to the CFMRC sensor development activities. Initially, efforts focus on sensor feasibility testing whereby several potential sensors are evaluated for technical and business issues such as sensitivity, reproducibility, cost, size, etc. After this initial screening, subsequent refinement of one or more chosen sensors occurs through beta-testing in a manufacturing environment to ensure viability for manufacturing applications. Lastly, commercialization with an existing supplier is critical in ensuring availability of the sensors for the industry. The examples described in this paper cover sensor development at all three stages in this evolutionary process.
Date: November 1, 1996
Creator: Cohen, S. & Kelly, M.
System: The UNT Digital Library
Modeling the surface evapotranspiration over the southern Great Plains (open access)

Modeling the surface evapotranspiration over the southern Great Plains

We have developed a method to apply the Simple Biosphere Model of Sellers et al to calculate the surface fluxes of sensible heat and water vapor at high spatial resolution over the domain of the US DOE`s Cloud and Radiation Testbed (CART) in Kansas and Oklahoma. The CART, which is within the GCIP area of interest for the Mississippi River Basin, is an extensively instrumented facility operated as part of the DOE`s Atmospheric Radiation Measurement (ARM) program. Flux values calculated with our method will be used to provide lower boundary conditions for numerical models to study the atmosphere over the CART domain.
Date: 1996-11~
Creator: Liljegren, J. C.; Doran, J. C.; Hubbe, J. M.; Shaw, W. J.; Zhong, S.; Collatz, G. J. et al.
System: The UNT Digital Library
Micromachined sensor and actuator research at Sandia`s Microelectronics Development Laboratory (open access)

Micromachined sensor and actuator research at Sandia`s Microelectronics Development Laboratory

An overview of the surface micromachining program at the Microelectronics Development Laboratory of Sandia National Laboratories is presented. Development efforts are underway for a variety of surface micromachined sensors and actuators for both defense and commercial applications. A technology that embeds micromechanical devices below the surface of the wafer prior to microelectronics fabrication has been developed for integrating microelectronics with surface-micromachined micromechanical devices. The application of chemical-mechanical polishing to increase the manufacturability of micromechanical devices is also presented.
Date: November 1, 1996
Creator: Smith, J.H.
System: The UNT Digital Library
Shock-wave properties of soda-lime glass (open access)

Shock-wave properties of soda-lime glass

Planar impact experiments and wave profile measurements provided single and double shock equation of state data to 30 GPa. Both compression wave wave profile structure and release wave data were used to infer time-dependent strength and equation of state properties for soda-lime glass.
Date: November 1996
Creator: Grady, D. E. & Chhabildas, L. C.
System: The UNT Digital Library
Effects of turbulence on power generation for variable-speed wind turbines (open access)

Effects of turbulence on power generation for variable-speed wind turbines

One of the primary advantages of variable-speed wind turbines over fixed-speed turbines should be improved aerodynamic efficiency. With variable-speed generation, in order to maintain a constant ratio of wind speed to tip speed, the wind turbine changes rotor speed as the wind speed changes. In this paper we compare a stall-controlled, variable-speed wind turbine to a fixed-speed turbine. The focus of this paper is to investigate the effects of variable speed on energy capture and its ability to control peak power. We also show the impact of turbulence on energy capture in moderate winds. In this report, we use a dynamic simulator to apply different winds to a wind turbine model. This model incorporates typical inertial and aerodynamic performance characteristics. From this study we found a control strategy that makes it possible to operate a stall-controlled turbine using variable speed to optimize energy capture and to control peak power. We also found that turbulence does not have a significant impact on energy capture.
Date: November 1, 1996
Creator: Muljadi, E.; Butterfield, C.P. & Buhl, M.L. Jr.
System: The UNT Digital Library
Quarkonia production at CDF (open access)

Quarkonia production at CDF

In this paper we present results on {ital J}/{Psi}, {Psi}(2{ital S}), {chi}{sub {ital c}} and {Gamma} production at {radical}{ital s} = 1.8 TeV. These results were obtained from data taken with the CDF detector at Fermilab. We cover recently completed analyses of the 1992-1995 collider run. We find an excess of {ital J}/{Psi}, {Psi}(2{ital S}) and {Gamma} production compared with the predictions from the Color Singlet Model. Prospects for the near future are also discussed.
Date: November 1, 1996
Creator: Papadimitriou, V.
System: The UNT Digital Library
Study of nuclei far from stability with AYE-Ball array (open access)

Study of nuclei far from stability with AYE-Ball array

The coupling of a Compton-suppressed Ge (CsGe) detector array to a recoil mass separator (RMS) has seen limited use in the past due to the low efficiency for measuring recoil-{gamma} ray coincidences (< 0.1%). With the building of new generation recoil separators and gamma-ray arrays, a substantial increase in detection efficiency has been achieved. This allows for the opportunity to measure excited states in nuclei with cross-sections approaching 100 nb. In this paper, results from the coupling of a modest array of CsGe detectors (AYE-Ball) with a recoil separator (FMA) will be presented.
Date: November 1, 1996
Creator: Carpenter, M.P.
System: The UNT Digital Library
Top quark study in all-jets channel at D0 (open access)

Top quark study in all-jets channel at D0

We report on the search for top quark decays into all-jets at the Tevatron collider. We measure preliminary cross sections of 4.4 {+-} 4.9 pb and 3.9 {+-} 9.8 pb for {ital t}{ital {anti t}} production, using singly and doubly {ital b}-tagged all-jets channels, respectively.
Date: November 1, 1996
Creator: Won, E.
System: The UNT Digital Library
Quest for the quantum limit in three dimensional metals (open access)

Quest for the quantum limit in three dimensional metals

The purpose of this work is to exploit ultra-high, flux compression type magnetic fields to achieve magnetic energies which are on the same or greater scale of the electronic structure in metallic systems. Under such conditions a metal. may become an insulator, may acquire a completely new electronic structure, or may develop novel configurations of electronic order. In this paper we consider experiments on quasi-two dimensional molecular conductors in both non-destructive pulsed fields to 60 T and in destructive flux compression fields to 700 T at low temperatures. New results on the molecular conductors {alpha}-(BEDT-TTF) {sub 2}NH{sub 4}Hg(SCN){sub 4} and (TMTSF){sub 2}ClO{sub 4} are discussed in experiments up to 60 T at low temperatures, and preliminary results on {alpha}-(BEDT-TTF){sub 2}NH{sub 4}Hg(SON){sub 4} in the 700 T MC1 series flux compression generators are presented. We argue that true direct dc electrical transport measurements in these materials at low temperatures up to 700 T appear to be within reach.
Date: November 1, 1996
Creator: Brooks, J. S.; Qualls, J. S. & Engel, L. W.
System: The UNT Digital Library
Summary proceedings of a workshop on Bioremediation and its Societal Implications and Concerns (BASIC) (open access)

Summary proceedings of a workshop on Bioremediation and its Societal Implications and Concerns (BASIC)

This document summarizes the proceedings of a workshop on Bioremediation and Its Societal Implications and Concerns (BASIC) held July 18-19, 1996 at the Airlie Center near Warrenton, Virginia. The workshop was sponsored by the Office of Health and Environmental Research (OHER), U.S. Department of Energy (DOE), as part of its fundamental research program in Natural and Accelerated Bioremediation Research (NABIR). The information summarized in these proceedings represents the general conclusions of the workshop participants, and not the opinions of workshop organizers or sponsors. Neither are they consensus opinions, as opinions differed among participants on a number of points. The general conclusions presented below were reached through a review, synthesis, and condensation of notes taken by NABIR Program Office staff and OHER program managers throughout the workshop. Specific contributions by participants during breakout sessions are recorded in bullet form in the appropriate sections, without attribution to the contributors. These contributions were transcribed as faithfully as possible from notes about the original discussions. They were edited only to make them grammatically correct, parallel in structure, and understandable to someone not familiar with the NABIR Program or BASIC element.
Date: November 1, 1996
Creator: Drell, D.W.; Metting, F.B. Jr. & Wuy, L.D.
System: The UNT Digital Library
High reflector absorptance measurements by the surface thermal lensing technique (open access)

High reflector absorptance measurements by the surface thermal lensing technique

Surface thermal lensing is an alternate configuration of a photothermal deflection system that was used to measure low levels of optical absorption. The thermal lensing configuration facilitated the alignment of the pump and probe laser beams by using a larger diameter probe beam. This technique was applied to high performance optical coatings, specifically high reflectors at 511 nm, zero degrees angle of incidence. The absorptance of these coatings was previously measured using a high power copper vapor laser system. A high power copper laser beam is focused onto a -2 mm diameter spot. A thermal camera senses the temperature rise with respect to the rest of the coating. The temperature change, power density and beam diameter were used with an empirical formula that yields optical absorption. The surface thermal lensing technique was able to resolve absorption levels lower than that achieved with the copper laser method.
Date: November 1, 1996
Creator: Chow, R.; Taylor, J. R.; Wu, Z. L.; Krupka, R. & Yang, T.
System: The UNT Digital Library
Comparison and modeling of aqueous dissolution rates of various uranium oxides (open access)

Comparison and modeling of aqueous dissolution rates of various uranium oxides

Purpose of this work was to measure and model the intrinsic dissolution rates of U oxides under a variety of well-controlled conditions that are relevant to a geologic repository. When exposed to air at elevated temperature, spent fuel may form the stable phase U{sub 3}O{sub 8}. Dehydrated schoepite, UO{sub 3}{center_dot}H{sub 2}O, exists in drip tests on spent fuel. Equivalent sets of U{sub 3}O{sub 8} and UO{sub 3}{center_dot}H{sub 2}O dissolution experiments allowed a systematic examination of the effects of temperature (25-75 C), pH(8-10), and carbonate (2-200x10{sup -4}molar) concentrations at atmospheric oxygen conditions. Results indicate that UO{sub 3}{center_dot}H{sub 2}O has a much higher dissolution rate (at least tenfold) than U{sub 3}O{sub 8} under the same conditions. The intrinsic dissolution rate of unirradiated U{sub 3}O{sub 8} is about twice that of UO{sub 2}. Dissolution of both U{sub 3}O{sub 8} and UO{sub 3}{center_dot}H{sub 2}O shows a very high sensitivity to carbonate concentration. Present results show a 25 to 50-fold increase in room-temperature UO{sub 3}{center_dot}H{sub 2}O dissolution rates between the highest and lowest carbonate concentrations. As with the UO{sub 2} dissolution data, the classical observed chemical kinetic rate law was used to model the U{sub 3}O{sub 8} dissolution rate data. The pH did not have …
Date: November 1, 1996
Creator: Steward, S.A.
System: The UNT Digital Library
Gaugino condensation, loop corrections and S-duality constraint (open access)

Gaugino condensation, loop corrections and S-duality constraint

This talk is a brief review of gaugino condensation in superstring effective field theories and some related issues (such as renormalization of the gauge coupling in the effective supergravity theories and modular anomaly cancellation). As a specific example, we discuss a model containing perturbative (1-loop) corrections to the K{umlt a}hler potential and approximate S-duality symmetry.
Date: November 1, 1996
Creator: Saririan, K.
System: The UNT Digital Library
Impact of beam smoothing method on direct drive target performance for the NIF (open access)

Impact of beam smoothing method on direct drive target performance for the NIF

The impact of smoothing method on the performance of a direct drive target is modeled and examined in terms of its l-mode spectrum. In particular, two classes of smoothing methods are compared, smoothing by spectral dispersion (SSD) and the induced spatial incoherence (ISI) method. It is found that SSD using sinusoidal phase modulation (FM) results in poor smoothing at low l-modes and therefore inferior target performance at both peak velocity and ignition. Modeling of the hydrodynamic nonlinearity shows that saturation tends to reduce the difference between target performance for the smoothing methods considered. However, using SSD with more generalized phase modulation results in a smoothed spatial spectrum, and therefore target performance, which is identical to that obtained with the ISI or similar method where random phase plates are present in both methods and identical beam divergence is assumed.
Date: November 1, 1996
Creator: Rothenberg, J.E. & Weber, S.V.
System: The UNT Digital Library
J/{psi} and {psi}{prime} suppression by comovers in Pb+Pb collisions (open access)

J/{psi} and {psi}{prime} suppression by comovers in Pb+Pb collisions

Measurements of {psi} and {psi}{prime} production at the CERN SPS are compared to predictions based on a hadronic model of charmonium suppression. Detailed information is presented to facilitate comparison to other analyses. Sensitivity of these conclusions to model parameters is discussed.
Date: November 1996
Creator: Gavin, S. & Vogt, R.
System: The UNT Digital Library
Modeling large heterogeneous RF structures (open access)

Modeling large heterogeneous RF structures

Large heterogeneous structures are difficult to model on a numerical grid because of the limitations on computing resources, so that alternate approaches such as equivalent circuits and mode-matching have been developed to treat this problem. This paper will describe the three methods and will analyze a structure representative of the SLAC and JLC detuned structures to compare the efficacy of each approach.
Date: November 1, 1996
Creator: Li, Zenghai; Ko, Kwok; Srinivas, V. & Higo, Toshiyasu
System: The UNT Digital Library
Conversion of ion-exchange resins, catalysts and sludges to glass with optional noble metal recovery using the GMODS process (open access)

Conversion of ion-exchange resins, catalysts and sludges to glass with optional noble metal recovery using the GMODS process

Chemical processing and cleanup of waste streams (air and water) typically result in products, clean air, clean water, and concentrated hazardous residues (ion exchange resins, catalysts, sludges, etc.). Typically, these streams contain significant quantities of complex organics. For disposal, it is desirable to destroy the organics and immobilize any heavy metals or radioactive components into stable waste forms. If there are noble metals in the residues, it is desirable to recover these for reuse. The Glass Material Oxidation and Dissolution System (GMODS) is a new process that directly converts radioactive and hazardous chemical wastes to borosilicate glass. GMODS oxidizes organics with the residue converted to glass; converts metals, ceramics, and amorphous solids to glass; converts halides (eg chlorides) to borosilicate glass and a secondary sodium halide stream; and recovers noble metals. GMODS has been demonstrated on a small laboratory scale (hundreds of grams), and the equipment needed for larger masses has been identified.
Date: November 1996
Creator: Forsberg, C. W. & Beahm, E. C.
System: The UNT Digital Library
Fully reconstructed B decay results from CDF (open access)

Fully reconstructed B decay results from CDF

We have measured ratios of branching ratios of {ital B} mesons including charmonium in the final state and use these ratios to derive {ital B} meson branching fractions. Results are also compared to predictions of factorization. We have searched for{ital B}{sup +}{sub {ital c}} {yields} {ital J}/{Psi}{pi}{sup +} and set a limit on {delta}{center_dot}{ital B}. We observe {Lambda}{sub {ital b}} {yields} {ital J}/{Psi}{Lambda} and measure the mass {ital M}({Lambda}{sub {ital b}}) = 5.623{+-} 0.005 {+-} 0.004 GeV/c{sup 2}.
Date: November 1, 1996
Creator: Lewis, J. D.
System: The UNT Digital Library
Particle production in Au + Au collisions from BNL E866 (open access)

Particle production in Au + Au collisions from BNL E866

In this article, we present recent results on particle production from Au+Au collisions at 11 A GeV/c obtained by the E866 experiment. The experiment studies the particle production in high baryon density matter created in central Au + Au collisions. Preliminary results of proton and pion production have been reported in previous Quark Matter conferences. Two particle correlation data for Au + Au collisions in this experiment are presented in another paper in this conference.
Date: November 1, 1996
Creator: Akiba, Y.; Hamagaki, H.; Homma, S. & Sako, H.
System: The UNT Digital Library
Building collaboration tools and access to on-line facilities (open access)

Building collaboration tools and access to on-line facilities

Network-based facilities will allow researchers at different locations to collaborate on experiments as if they all were together in the same laboratory. The expected value of these geographically distributed environments includes substantially increased effectiveness in doing science, and an enabling capability for analytical and high-value production use by industry. The Distributed, Collaboratory Experiment Environments (DCEE) Program consists of four projects that were established to build prototype remote experiment and collaborative environments. The work undertaken in this project represents some of the research and development of the mechanisms and infrastructure required to make collaboratories a reality. Some of these mechanisms have already been developed. Several other mechanisms, such as data dissemination, resource management for the sharing of experiment control, safety and security, electronic notebooks, elements of telepresence, and integrated user interfaces need further research and development. The pilot application for these collaborative tools is the Advanced Light Source (ALS) Beamline 7.0 at the Ernest Orlando Lawrence Berkeley Laboratory. The ALS is a particle accelerator and is a source of very high brilliance soft X-ray beams. One experimental facility is the Spectro-Microscopy Facility Beamline 7.0. Through this project, the Spectro-Microscopy Facility will be opened up to users from a wide range of …
Date: November 1, 1996
Creator: Agarwal, D. & Sachs, S.
System: The UNT Digital Library
Probing quartic couplings through three gauge boson production at an e{sup +}e{sup {minus}} linear collider (open access)

Probing quartic couplings through three gauge boson production at an e{sup +}e{sup {minus}} linear collider

We explore the capability of a 500 or 1000 GeV e{sup +} e{sup {minus}} linear collider to measure anomalous quartic gauge boson couplings. In the framework of a non-linear effective Lagrangian with a custodial SU(2) symmetry, there are only two next-to-leading order operators which contribute to quartic, but not to two- and three-gauge boson interactions. The limits on the coefficients of these operators from present and future e{sup +} e{sup {minus}} colliders are compared with those available from other sources.
Date: November 22, 1996
Creator: Dawson, S.; Likhoded, A.; Valencia, G. & Yushchenko, O.
System: The UNT Digital Library