Boron-enhanced diffusion of boron from ultralow-energy boron implantation (open access)

Boron-enhanced diffusion of boron from ultralow-energy boron implantation

The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B{sup +}, the threshold implantation dose which leads to BED lies between 3 {times} 10{sup 14} and of 1 {times} 10{sup 15}/cm{sup {minus}2}. Formation of the shallowest possible junctions by 0.5 keV B{sup +} requires that the implant dose be kept lower than this threshold.
Date: May 3, 1998
Creator: Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C. et al.
Object Type: Report
System: The UNT Digital Library
ISCR annual report FY 1998 (open access)

ISCR annual report FY 1998

Advances in scientific computing research have never been more vital to the core missions of Lawrence Livermore National Laboratory than they are today. These advances are evolving so rapidly, and over such a broad front of computational science, that to remain on the leading edge, the Laboratory must collaborate with many academic centers of excellence. In FY 1998, ISCR dramatically expanded its interactions with academia through collaborations, visiting faculty, guests and a seminar series. The pages of this annual report summarize the activities of the 63 faculty members and 34 students who participated in ISCR collaborative activities during FY 1998. The 1998 ISCR call for proposals issued by the University Collaborative Research Program (UCRP) resulted in eight awards made by the University of California Office of the President to research teams at UC San Diego, UC Davis, UC Los Angeles, and UC Berkeley. These projects are noted. ISCR is now part of the Laboratory�s Center for Applied Scientific Computing (CASC). Many CASC scientists participate actively in ISCR�University collaborations, as noted. The eight collaborations shown represent innovative research efforts supported by ISCR in FY 1998. Abstracts discussing each of these collaborations begin on page 79. The Accelerated Strategic Computing Initiative (ASCI) …
Date: May 3, 1999
Creator: Alchorn, A & Fitzgerald, J M
Object Type: Report
System: The UNT Digital Library
Tanks Focus Area (TFA) Site Needs Assessment FY 1999 (open access)

Tanks Focus Area (TFA) Site Needs Assessment FY 1999

This report documents the process used by the Tanks Focus Area (TFA) to analyze and develop responses to technology needs submitted by five major U.S. Department of Energy (DOE) sites with radioactive tank waste problems, and the initial results of the analysis. The sites are the Hanford Site, Idaho National Engineering and Environmental Laboratory (INEEL), Oak Ridge Reservation (ORR), Savannah River Site (SRS), and West Valley Demonstration Project (WVDP). This is the fifth edition of the TFA site needs assessment. As with previous editions, this edition serves to provide the basis for accurately defining the TFA program for the upcoming fiscal year (FY), and adds definition to the program for up to 4 additional outyears. Therefore, this version distinctly defines the FY 2000 progrti and adds further definition to the FY 2001- FY 2004 program. Each year, the TFA reviews and amends its program in response to site users' science and technology needs.
Date: May 3, 1999
Creator: Allen, RW
Object Type: Report
System: The UNT Digital Library
Heating of nuclear matter and multifragmentation : antiprotons vs. pions. (open access)

Heating of nuclear matter and multifragmentation : antiprotons vs. pions.

Heating of nuclear matter with 8 GeV/c {bar p} and {pi}{sup {minus}} beams has been investigated in an experiment conducted at BNL AGS accelerator. All charged particles from protons to Z {approx_equal} 16 were detected using the Indiana Silicon Sphere 4{pi} array. Significant enhancement of energy deposition in high multiplicity events is observed for antiprotons compared to other hadron beams. The experimental trends are qualitatively consistent with predictions from an intranuclear cascade code.
Date: May 3, 1999
Creator: Back, B.; Beaulieu, L.; Breuer, H.; Gushue, S.; Hsi, W.-C.; Korteling, R. G. et al.
Object Type: Article
System: The UNT Digital Library
Heating {sup 197}Au nuclei with 8 GeV antiproton and {pi}- beams. (open access)

Heating {sup 197}Au nuclei with 8 GeV antiproton and {pi}- beams.

This contribution stresses results recently obtained from experiment E900 performed at the Brookhaven AGS accelerator with 8 GeV/c antiproton and negative pion beams using the Indiana Silicon Sphere detector array. An investigation of the reaction mechanism is presented, along with source characteristics deduced from a two-component fit to the spectra. An enhancement of deposition energy with the antiproton beam with respect to the pion beam is observed. The results are qualitatively consistent with predictions of an intranuclear cascade code.
Date: May 3, 1999
Creator: Back, B.; Beaulieu, L.; Breuer, H.; Gushue, S.; Hsi, W.-C.; Korteling, R. G. et al.
Object Type: Article
System: The UNT Digital Library
Isolating the thermal degree of freedom in nuclear multifragmentation. (open access)

Isolating the thermal degree of freedom in nuclear multifragmentation.

Multifragmentation studies induced by GeV light-ion beams permit investigation of the influence of intrinsic thermal properties of hot nuclear matter, with minimal interference from the compression/decompression cycle and rotational instabilities. We summarize recent results obtained with {sup 3}He, proton and pion beams up to 15 GeV/c and present the initial results from a recent experiment with 8 GeV/c antiproton and pion beams. The results are compared with INC simulations coupled to EES and SMM models and the caloric curve for the {sup 3}He data will also be discussed.
Date: May 3, 1999
Creator: Back, B.; Beaulieu, L.; Breuer, H.; Gushue, S.; Hsi, W.-C.; Korteling, R. G. et al.
Object Type: Article
System: The UNT Digital Library
Influence of Rapid Thermal Ramp Rate on Phase Transformation of Titanium Silicides (open access)

Influence of Rapid Thermal Ramp Rate on Phase Transformation of Titanium Silicides

ULSI technology requires low resistance, stable silicides formed on small geometry lines. Titanium disilicide (TiSiz), which is the most widely used silicide for ULSI applications, exists in two crystallographic phases: the high resistance, metastable C49 phase and the low resistance, stable C54 phase. The major issue with TiSiz is the increasing thermal budget required to transform the C49 phase into the low resistance C54 phase as linewiths decrease below 0.25 pm. Annealing above 900"C to obtain this transformation often results in thermal degradation, so it is desirable to reduce the transformation temperature. The transformation temperature has been shown to be a fi.mction of many factors including microstructure, grain size, and impurities. In this paper we report an investig+ion of rapid thermal silicidation of titanium films (250, 400, and 600 A) on single crystalline silicon at temperatures from 300 to 1000"C. The ramp rates for these experiments are 5, 30, 70, and 200oC/s. The transformation temperature decreases as the ramp rate increases and as the initial film thickness increases. Scanning electron microscopy (SEM) is used to analyze the resultant film microstructure. The ramp rate influence on Ti silicidation is also investigated on polycrystalline Si lines with widths ranging from 0.27 to …
Date: May 3, 1999
Creator: Bailey, Glenn; Hu, Yao, Zhi; Smith, Paul Martin; Tay, Sing Pin; Thakur, Randhir & Yang, Jiting
Object Type: Article
System: The UNT Digital Library
Scale up issues involved with the ceramic waste form : ceramic-container interactions and ceramic cracking quantification. (open access)

Scale up issues involved with the ceramic waste form : ceramic-container interactions and ceramic cracking quantification.

Argonne National Laboratory is developing a process for the conditioning of spent nuclear fuel to prepare the material for final disposal. Two waste streams will result from the treatment process, a stainless steel based form and a ceramic based form. The ceramic waste form will be enclosed in a stainless steel container. In order to assess the performance of the ceramic waste form in a repository two factors must be examined, the surface area increases caused by waste form cracking and any ceramic/canister interactions that may release toxic material. The results indicate that the surface area increases are less than the High Level Waste glass and any toxic releases are below regulatory limits.
Date: May 3, 1999
Creator: Bateman, K. J.; DiSanto, T.; Goff, K. M.; Johnson, S. G.; O'Holleran, T. & Riley, W. P., Jr.
Object Type: Article
System: The UNT Digital Library
Sign-Selected Quadrupole Train (open access)

Sign-Selected Quadrupole Train

The design of the Sign-Selected Quadrupole Train for E-815 (NuTeV) is set forth. The relevant physics requirements are explained. The optics of the beam are presented, along with an explanation of the proton dumping scheme. A discussion of rates and backgrounds follows, with special care given to backgrounds from scraping and obstructions. The relevant tolerances for beam construction are given and justified by simulations of the beamline. This leads to a discussion of the beam monitoring.
Date: May 3, 1994
Creator: Bernstein, R.
Object Type: Report
System: The UNT Digital Library
Improvement of Photosynthetic Efficiency Through Reduction of Chlorophyll Antenna Size (open access)

Improvement of Photosynthetic Efficiency Through Reduction of Chlorophyll Antenna Size

We have previously presented a graphical illustration of a strategy to improve photosynthetic conversion efficiencies by a reduction of the antenna size in photosynthetic reaction centers. During the current reporting period, we have made progress in demonstrating the conceptual correctness of this idea. Light-saturation studies for CO, in air were performed with an antenna-deficient mutant of Chlamydomonas (DS521) and the wild type (DES15). The light-saturated rate for CO(2), assimilation in mutant DS521 was about two times higher (187 Mu-mol.h(-1).mg chl(-1)) than that of the wild type, DES15 (95 Mu-mol.h(-1).mg chl(-1). Significantly, a partial linearization of the light-saturation curve was also observed. The light intensities that give half-saturation of the photosynthetic rate were 276 and 152 Mu-E.m(-2).s(-1) in DS521 and DES15, respectively. These results confirmed that DS521 has a smaller chlorophyll antenna size and demonstrated that the reduction of antenna size can indeed improve the overall efficiency of photon utilization. Corresponding experiments were also performed with CO(2), in helium. Under this anaerobic condition, no photoinhibition was observed, even at elevated light intensities. Photoinhibition occurs under aerobic conditions. The antenna-deficient mutant DS521 can also provide significant resistance to photoinhibition, in addition to the improvement in the overall efficiency in CO(2), fixation.
Date: May 3, 1999
Creator: Blankinship, S.L.; Greenbaum, E.; Lee, J.W. & Mets, L.
Object Type: Article
System: The UNT Digital Library
Portable data acquisition system (open access)

Portable data acquisition system

Lawrence Livermore National Laboratory (LLNL) has developed a Portable Data Acquisition (DAQ) System that is basically a laboratory-scale of Program Logic Control (PLC). This DAQ system can obtain signals from numerous sensors (e.g., pH, level, pressure, flow meters), open and close valves, and turn on and off pumps. The data can then be saved on a spreadsheet or displayed as a graph/indicator in real-time on a computer screen. The whole DAQ system was designed to be portable so that it could sit on a bench top during laboratory-scale treatability studies, or moved out into the field during larger studies. This DAQ system is also fairly simple to use. All that is required is some working knowledge of LabVIEW 4.1, and how to properly wire the process equipment. The DAQ system has been used during treatability studies on cesium precipitation, controlled hydrolysis of water- reactive wastes, and other waste treatment studies that enable LLNL to comply with the Federal Facility Compliance Act (FFCAct). Improved data acquisition allows the study to be better monitored, and therefore better controlled, and can be used to determine the results of the treatment study more effectively. This also contributes to the design of larger treatment processes.
Date: May 3, 1999
Creator: Bowers, J & Rogers, H
Object Type: Article
System: The UNT Digital Library
Computer-Aided dispatching system design specification (open access)

Computer-Aided dispatching system design specification

This document defines the performance requirements for a graphic display dispatching system to support Hanford Patrol emergency response. This system is defined as a Commercial-Off the-Shelf computer dispatching system providing both text and graphical display information while interfacing with the diverse reporting system within the Hanford Facility. This system also provided expansion capabilities to integrate Hanford Fire and the Occurrence Notification Center and provides back-up capabilities for the Plutonium Processing Facility.
Date: May 3, 1996
Creator: Briggs, M. G.
Object Type: Report
System: The UNT Digital Library
A novel method for diagnosing the growth of subresolution-scale perturbations (open access)

A novel method for diagnosing the growth of subresolution-scale perturbations

We have demonstrated a technique for diagnosing the growth of subresolution-scale perturbations by the appearance of longer-wavelength, coupled modes once the growth has proceeded into the nonlinear regime. Comparison of the growth rate of this larger scale feature with numerical simulations can then be used to infer the growth rates of the initial perturbations. This experiment was conceived as an analog of large-scale computer simulations where the large eddy approximation is applied. There a subgrid-scale model is used to represent the effects of small scales on large-scale motion, which is directly numerically simulated.
Date: May 3, 1996
Creator: Budil, K. S.; Remington, B. A. & Perry, T. S.
Object Type: Article
System: The UNT Digital Library
Implementing Management Systems-Based Assessments (open access)

Implementing Management Systems-Based Assessments

A management system approach for evaluating environment, safety, health, and quality is in use at Sandia National Laboratories (SNL). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000. As a multi-program national laboratory, SNL has many diverse operations including research, engineering development and applications, production, and central services supporting all activities and operations. Basic research examples include fusion power generation, nuclear reactor experiments, and investigation of combustion processes. Engineering development examples are design, testing, and prototype developments of micro-mechanical systems for safe'~arding computer systems, air bags for automobiles, satellite systems, design of transportation systems for nuclear materials, and systems for use in medical applications such as diagnostics and surgery. Production operations include manufacture of instrumented detection devices, radioisotopes, and replacement parts for previously produced engineered systems. Support services include facilities engineering, construction, and site management, site security, packaging and transportation of hazardous materials wastes, ES&H functional programs to establish requirements and guidance to comply with federal, state, local, and contractual requirements and work safety. In this diverse environment, unlike more traditional single function business units, an integrated consistent management system is not typical. Instead, each type …
Date: May 3, 1999
Creator: Campisi, John A. & Reese, Robert T.
Object Type: Article
System: The UNT Digital Library
Status of the new muon (g - 2) experiment. (open access)

Status of the new muon (g - 2) experiment.

The new muon (g - 2) experiment is now fully operational The goal of the experiment is to obtain a relative error on (g - 2) of {+-}O.35 ppm to measure the electroweak contribution for the first time, and to observe, or place stringent limits on physics beyond the standard model which can contribute to (g - 2). A brief status report is presented.
Date: May 3, 1999
Creator: Carey, R. M.; Earle, W.; Efstathiadis, E.; Hare, M. F.; Collaboration, MUON (g - 2); Nodulman, L. et al.
Object Type: Article
System: The UNT Digital Library
Certification of MCNP Version 4A for WHC computer platforms. Revision 7 (open access)

Certification of MCNP Version 4A for WHC computer platforms. Revision 7

MCNP is a general-purpose Monte Carlo code that can be used for neutron, photon, or coupled neutron/photon transport, including the capability to calculate eigenvalues for critical systems. The code treats an arbitrary three-dimensional configuration of materials in geometric cells bounded by first- and second-degree surfaces, and some special fourth-degree surfaces (elliptical tori).
Date: May 3, 1995
Creator: Carter, L. L.
Object Type: Report
System: The UNT Digital Library
Aqueous biphasic systems for metal separations : a microcalorimetric analysis of polymer/salt interactions. (open access)

Aqueous biphasic systems for metal separations : a microcalorimetric analysis of polymer/salt interactions.

Certain radionuclide ions (e.g., TcO{sub 4}{sup 16}) exhibit unusually strong Affinities toward the polymer-rich phase in aqueous biphase systems generated by combinations of salt solutions with polymers such as poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG). Thus, aqueous polymer phases could potentially be used to selectively extract these ions during pretreatment of radioactive tank wastes at Hanford. To help develop a fundamental understanding of the interactions between various ions and polymers in aqueous solution, interaction enthalpies between sodium perrhenate and a random copolymer of PEG and PPG (UCON-50) were measured by microcalorimetric titration. An entropy compensation effect was observed in this system in which changes in enthalpic interactions were balanced by entropy changes such that the interaction free energy remained constant and approximately equal to zero.
Date: May 3, 1999
Creator: Chaiko, D. J.; Hatton, T. A. & Zaslavsky, B.
Object Type: Article
System: The UNT Digital Library
Interim Results from Alternative Fuel Truck Evaluation Project (open access)

Interim Results from Alternative Fuel Truck Evaluation Project

The objective of this project, which is supported by the U.S. Department of Energy (DOE) through the National Renewable Energy Laboratory (NREL), is to provide a comprehensive comparison of heavy-duty trucks operating on alternative fuels and diesel fuel. Data collection from up to eight sites is planned. Currently, the project has four sites: Raley's in Sacramento, CA (Kenworth, Cummins LlO-300G, liquefied natural gas - LNG); Pima Gro Systems, Inc. in Fontana, CA (White/GMC, Caterpillar 31768 Dual-Fuel, compressed natural gas - CNG); Waste Management in Washington, PA (Mack, Mack E7G, LNG); and United Parcel Service in Hartford, CT (Freightliner Custom Chassis, Cummins B5.9G, CNG). This paper summarizes current data collection and evaluation results from this project.
Date: May 3, 1999
Creator: Chandler, Kevin L.; Norton, Paul & Clark, Nigel
Object Type: Article
System: The UNT Digital Library
W, Z + jets at Tevatron (open access)

W, Z + jets at Tevatron

We report the production jet cross-sections and properties in W and Z events using data from collisions with {radical}s = 1800 GeV at Fermilab Tevatron. Observed distributions in general agree with predictions of leading order QCD matrix element calculations with added gluon radiations and simulated parton fragmentations; however, some limitations of LO QCD predictions are also observed. The cross-section ratio of W + {>=} 1 jet events to inclusive W events is reported and compared with next-to-the-leading order QCD expectations. Good agreement between data and theory is seen. The color coherence effects are also observed in W+ jets events.
Date: May 3, 1999
Creator: Chang, Paoti
Object Type: Article
System: The UNT Digital Library
A lattice gas model for thermohydrodynamics (open access)

A lattice gas model for thermohydrodynamics

The FHP lattice gas model is extended to include a temperature variable in order to study thermohydrodynamics. The compressible Navier-Stokes equations are derived using a Chapman-Enskog expansion. Heat conduction and convention problems are investigated, including Benard convention. It is shown that the usual FHP rescaling procedure can be avoided by controlling the temperature. 20 refs., 12 figs.
Date: May 3, 1990
Creator: Chen, Shiyi; Chen, Hudong; Doolen, G. D.; Gutman, S. & Lee, M.
Object Type: Article
System: The UNT Digital Library
Application of the New City-Suburban Heavy Vehicle Route (CSHVR) to Truck Emissions Characterization (open access)

Application of the New City-Suburban Heavy Vehicle Route (CSHVR) to Truck Emissions Characterization

Speed-time and video data were tractor-trailers performing local deliveries in logged for Akron, OH. and Richmond, VA. in order to develop an emissions test schedule that represented real truck use. The data bank developed using these logging techniques was used to create a Yard cycle, a Freeway cycle and a City-Suburban cycle by the concatenation of microtrips. The City-Suburban driving cycle was converted to a driving route, in which the truck under test would perform at maximum acceleration during certain portions of the test schedule. This new route was used to characterize the emissions of a 1982 Ford tractor with a Cummins 14 liter, 350 hp engine and a 1998 International tractor with a Cummins 14 liter, 435 hp engine. Emissions levels were found to be repeatable with one driver and the drier-to-driver variation of NO{sub x} was under 4%, although the driver-to driver variations of CO and PM were higher. Emissions levels of NO{sub x} for the Ford tractor at a test weight of 46,400 lb. u sing the CSHVR were comparable with values obtained using the WVU 5 mile route and the EPA Urban Dynamometer Driving Schedule for Heavy Duty Vehicles (''Test D''). The PM missions were slightly …
Date: May 3, 1999
Creator: Clark, Nigel N.; Daley, James J.; Nine, Ralph D. & Atkinson, Christopher M.
Object Type: Article
System: The UNT Digital Library
Diesel and CNG Transit Bus Emissions Characterization By Two Chassis Dynamometer Laboratories: Results and Issues (open access)

Diesel and CNG Transit Bus Emissions Characterization By Two Chassis Dynamometer Laboratories: Results and Issues

Emissions of six 32 passenger transit buses were characterized using one of the West Virginia University (WVU) Transportable Heavy Duty Emissions Testing Laboratories, and the fixed base chassis dynamometer at the Colorado Institute for Fuels and High Altitude Engine Research (CIFHAER). Three of the buses were powered with 1997 ISB 5.9 liter Cummins diesel engines, and three were powered with the 1997 5.9 liter Cummins natural gas (NG) counterpart. The NG engines were LEV certified. Objectives were to contrast the emissions performance of the diesel and NG units, and to compare results from the two laboratories. Both laboratories found that oxides of nitrogen and particulate matter (PM) emissions were substantially lower for the natural gas buses than for the diesel buses. It was observed that by varying the rapidity of pedal movement during accelerations in the Central Business District cycle (CBD), CO and PM emissions from the diesel buses could be varied by a factor of three or more. The driving styles may be characterized as aggressive and non-aggressive, but both styles followed the CBD speed command acceptably. PM emissions were far higher for the aggressive driving style. For the NG fueled vehicles driving style had a similar, although smaller, …
Date: May 3, 1999
Creator: Clark, Nigel N.; Rapp, Byron L.; Lyons, Donald W.; Graboski, Michael S.; McCormick, Robert L.; Alleman, Teresa L. et al.
Object Type: Article
System: The UNT Digital Library
Interfacing Detectors to Triggers And DAQ Electronics (open access)

Interfacing Detectors to Triggers And DAQ Electronics

The complete design of the front-end electronics interfacing LHCb detectors, Level-0 trigger and higher levels of trigger with flexible configuration parameters has been made for (a) ASIC implementation, and (b) FPGA implementation. The importance of approaching designs in technology-independent form becomes essential with the actual rapid electronics evolution. Being able to constrain the entire design to a few types of replicated components: (a) the fully programmable 3D-Flow system, and (b) the configurable front-end circuit described in this article, provides even further advantages because only one or two types of components will need to migrate to the newer technologies. To base on today's technology the design of a system such as the LHCb project that is to begin working in 2006 is not cost-effective. The effort required to migrate to a higher-performance will, in that case, be almost equivalent to completely redesigning the architecture from scratch. The proposed technology independent design with the current configurable front-end module described in this article and the scalable 3D-Flow fully programmable system described elsewhere, based on the study of the evolution of electronics during the past few years and the forecasted advances in the years to come, aims to provide a technology-independent design which lends …
Date: May 3, 1999
Creator: Crosetto, Dario B.
Object Type: Report
System: The UNT Digital Library
The Human Genome Project and Mental Retardation: An Educational Program. Final Progress Report (open access)

The Human Genome Project and Mental Retardation: An Educational Program. Final Progress Report

The Arc, a national organization on mental retardation, conducted an educational program for members, many of whom have a family member with a genetic condition causing mental retardation. The project informed members about the Human Genome scientific efforts, conducted training regarding ethical, legal and social implications and involved members in issue discussions. Short reports and fact sheets on genetic and ELSI topics were disseminated to 2,200 of the Arc's leaders across the country and to other interested individuals. Materials produced by the project can e found on the Arc's web site, TheArc.org.
Date: May 3, 1999
Creator: Davis, Sharon
Object Type: Report
System: The UNT Digital Library