Micromilling of Metal Alloys with Focused Ion Beam-Fabricated Tools (open access)

Micromilling of Metal Alloys with Focused Ion Beam-Fabricated Tools

This work combines focused ion beam sputtering and ultra-precision machining as a first step in fabricating microstructure in metals and alloys. Specifically, {approx}25{micro}m diameter micro-end mills are made from cobalt M42 high-speed steel and C2 micrograin tungsten carbide tool blanks by ion beam sputtering. A 20 keV focused gallium beam defines tool cutting edges having radii of curvature < 0.1{micro}m. Micro-end mills having 2, 4 and 5 cutting edges successfully machine small trenches in 6061-T4 aluminum, brass, 4340 steel and polymethyl methacrylate. Machined trench widths are approximately equal to the tool diameters and surface roughnesses (rms) are {approx}150 nm or less. Microtools are robust and operate for more than 6 hours without fracture. Results from ultra-precision machining aluminum at feed rates as high as 50 mm/minute are included.
Date: November 5, 1999
Creator: ADAMS,DAVID P.; VASILE,M.J.; BENAVIDES,GILBERT L. & CAMPBELL,ANN N.
Object Type: Article
System: The UNT Digital Library
Ion Beam Sputter Fabrication of Micro-Grooving and Micro-Threading Tools (open access)

Ion Beam Sputter Fabrication of Micro-Grooving and Micro-Threading Tools

This paper presents techniques for fabricating microscopic, nonplanar features in a variety of materials. Micro-grooving and micro-threading tools having cutting dimensions of 10-30{micro}m are made by focused ion beam sputtering and used in ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide. This creates cutting edges having radii of curvature less than 0.4 {micro}m, and rake features similar to conventional lathe tools. Clearance for minimizing frictional drag of a tool results from the sputter yield dependence on ion herd target incidence angle. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close matching between tool width and feature size. Microtools controllably machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061-T6 Al cylindrical substrates. Micro-grooving tools also fabricate sinusoidal waveform features in polished metal substrates.
Date: November 5, 1999
Creator: Adams,David P.; Vasile,M. J. & Krishnan,A. S. M.
Object Type: Article
System: The UNT Digital Library
Single top production and top properties at the Tevatron (open access)

Single top production and top properties at the Tevatron

We summarize recent measurements made at the Tevatron Collider using top event candidates. Cross section and mass measurements are discussed in a separate contribution to these Proceedings. Here we report on studies of the top P<sub>T</sub> distribution in t{anti t} production and studies of single top production. Properties of top decays examined are: BF(t {yields} Wb)/BF(t {yields} Wq), helicity amplitudes of W's from top decays and correlations of t{anti t} decay products. Searches for new physics in rare top decays and a search for a state X {yields} t{anti t} are also reported.
Date: November 5, 1999
Creator: Barbaro-Galtieri, Angela
Object Type: Article
System: The UNT Digital Library
An updated measurement of sin (2{Beta}) at CDF (open access)

An updated measurement of sin (2{Beta}) at CDF

We report an updated direct measurement of the Standard Model CP violation parameter sin(2{beta}) using the CDF Detector at Fermilab. We use the entire Run-I data sample of 110 pb{sup -1} of proton-antiproton collisions at {radical}s = 1.8 TeV. In this analysis, we have combined three tagging methods: a same-side tag, a soft-lepton tag, and a jet-charge tag, and also added events that have less precise lifetime information because they are not fully contained within the acceptance of the SVX. The signal sample consists of {approx} 400 B {yields} J/{psi} K{sub S}{sup 0} events. A maximum likelihood fitting method is used to measure sin(2{beta}) = 0.79{sub -0.44}{sup +0.41} (stat.+syst.). We calculate a 93% Feldman-Cousins confidence interval of 0 &lt; sin(2{beta}) &lt; 1. This measurement is the best direct indication for CP violation in the neutral B meson sector to date. The sin(2{beta}) value is consistent with the Standard Model prediction of large CP symmetry violation in the b quark system.
Date: November 5, 1999
Creator: Bedeschi, Franco
Object Type: Article
System: The UNT Digital Library
The NLC Injector System (open access)

The NLC Injector System

The Next Linear Collider (NW) Injector System is designed to produce low emittance, 10 GeV electron and positron beams at 120 hertz for injection into the NLC main linacs. Each beam consists of a train of 9.5 bunches spaced by 2.8 ns; each bunch has a population of 1.15 x 10{sup 10} particles. At injection into the main linacs, the horizontal and vertical emittances are specified to be {gamma}{var_epsilon}{sub x} = 3 x 10{sup -6} m-rad and {gamma}{var_epsilon}{sub y} = 3 x 10{sup -8} m-rad and the bunch length is 100 {micro}m. Electron polarization of greater than 80% is required. Electron and positron beams are generated in separate accelerator complexes each of which contain the source, damping ring systems, L-band, S-band, and X-band linacs, bunch length compressors, and collimation regions. The need for low technical risk, reliable injector subsystems is a major consideration in the design effort. This paper presents an overview of the NLC injector systems.
Date: November 5, 1999
Creator: Bharadwaj, V.; Clendenin, J. E.; Emma, P.; Frisch, J.; Jobe, R.; Kotseroglou, T. et al.
Object Type: Article
System: The UNT Digital Library
Tungsten Z-Pinch Long Implosions on the Saturn Generator (open access)

Tungsten Z-Pinch Long Implosions on the Saturn Generator

Recent success on the Saturn and Z accelerators at Sandia National Laboratories have demonstrated the ability to scale z-pinch parameters to increasingly larger current pulsed power facilities. Next generation machines will require even larger currents (&gt;20 MA), placing further demands on pulsed power technology. To this end, experiments have been carried out on Saturn operating in a long pulse mode, investigating the potential of lower voltages and longer implosion times while still maintaining pinch fidelity. High wire number, 25 mm diameter tungsten arrays were imploded with implosion times ranging from 130 to 240 ns. The results were comparable to those observed in the Saturn short pulse mode, with risetimes on the order of 4.5 to 6.5 ns. Experimental data will be presented, along with two dimensional radiation magnetohydrodynamic simulations used to explain and reproduce the experiment.
Date: November 5, 1999
Creator: Douglas, Melissa R.; Deeney, Christopher; Spielman, Rick B.; Coverdale, Christine A.; Roderick, N. F. & Haines, M. G.
Object Type: Article
System: The UNT Digital Library
HCCI in a CFR engine: experiments and detailed kinetic modeling (open access)

HCCI in a CFR engine: experiments and detailed kinetic modeling

Single cylinder engine experiments and chemical kinetic modeling have been performed to study the effect of variations in fuel, equivalence ratio, and intake charge temperature on the start of combustion and the heat release rate. Neat propane and a fuel blend of 15% dimethyl-ether in methane have been studied. The results demonstrate the role of these parameters on the start of combustion, efficiency, imep, and emissions. Single zone kinetic modeling results show the trends consistent with the experimental results.
Date: November 5, 1999
Creator: Flowers, D; Aceves, S; Smith, R; Torres, J; Girard, J & Dibble, R
Object Type: Article
System: The UNT Digital Library
Analysis of Dry Storage Temperature Limits for Zircaloy-Clad Spent Nuclear Fuel (open access)

Analysis of Dry Storage Temperature Limits for Zircaloy-Clad Spent Nuclear Fuel

Safe interim dry storage of spent nuclear fuel (SNF) must be maintained for a minimum of twenty years according to the Code of Federal Regulations. The most important variable that must be regulated by dry storage licensees in order to meet current safety standards is the temperature of the SNF. The two currently accepted models to define the maximum allowable initial storage temperature for SNF are based on the diffusion controlled cavity growth (DCCG) failure mechanism proposed by Raj and Ashby. These models may not give conservative temperature limits. Some have suggested using a strain-based failure model to predict the maximum allowable temperatures, but we have shown that this is not applicable to the SNF as long as DCCG is the assumed failure mechanism. Although the two accepted models are based on the same fundamental failure theory (DCCG), the researchers who developed the models made different assumptions, including selection of some of the most critical variables in the DCCG failure equation. These inconsistencies are discussed together with recommended modifications to the failure models based on more recent data.
Date: November 5, 1999
Creator: Hayes, T.A.; Kassner, M.D. & Vecchio, K.S.
Object Type: Article
System: The UNT Digital Library
Single top and top properties at CDF (open access)

Single top and top properties at CDF

Recent CDF results with 110 pb{sup -1} of data on top quark production and decay properties are presented. Limits are placed on single top quark production in the W* and W-gluon channels. A measurement of the polarization of the intermediate W boson in top decay, a search for resonances in the mass of the t{bar t} system, and the transverse momentum of top quarks in t{bar t} events are presented.
Date: November 5, 1999
Creator: Koehn, P.
Object Type: Article
System: The UNT Digital Library
Dynamics of the Inflationary Era (open access)

Dynamics of the Inflationary Era

There is very strong circumstantial evidence that there was an inflationary epoch very early in the history of the universe. In this lecture the author describes how we might be able to piece together some understanding of the dynamics during and immediately after the inflationary epoch.
Date: November 5, 1999
Creator: Kolb, Edward W.
Object Type: Article
System: The UNT Digital Library
Recent Developments in the Design of the NLC Positron Source (open access)

Recent Developments in the Design of the NLC Positron Source

Recent developments in the design of the Next Linear Collider (NLC) positron source based on updated beam parameters are described. The unpolarized NLC positron source [1,2] consists of a dedicated 6.2 GeV S-band electron accelerator, a high-Z positron production target, a capture system and an L-band positron linac. The 1998 failure of the SLC target, which is currently under investigation, may lead to a variation of the target design. Progress towards a polarized positron source is also presented. A moderately polarized positron beam colliding with a highly polarized electron beam results in an effective polarization large enough to explore new physics at NLC. One of the schemes towards a polarized positron source incorporates a polarized electron source, a 50 MeV electron accelerator, a thin target for positron production and a new capture system optimized for high-energy, small angular-divergence positrons. The yield for such a process, checked using the EGS4 code, is of the order of 10{sup -3}. The EGS4 code has being enhanced to include the effect of polarization in bremsstrahlung and pair-production process.
Date: November 5, 1999
Creator: Kotseroglou, T.; Bharadwaj, V.; Clendenin, J. E.; Ecklund, S,; Frisch, J.; Krejcik, P. et al.
Object Type: Article
System: The UNT Digital Library
FY 1999 Annual Self-Evaluation Report of the Pacific Northwest National Laboratory (open access)

FY 1999 Annual Self-Evaluation Report of the Pacific Northwest National Laboratory

This is a report of the Pacific Northwest National Laboratory's (Pacific Northwest's) FY1999 Annual Self-Evaluation Report. This report summarizes our progress toward accomplishment of the critical outcomes, objectives, and performance indicators as delineated in the FY1999 Performance Evaluation & Fee Agreement. It also summarizes our analysis of the results of Pacific Northwest's Division and Directorate annual self-assessments, and the implementation of our key operational improvement initiatives. Together, these provide an indication of how well we have used our Integrated Assessment processes to identify and plan improvements for FY2000. As you review the report you will find areas of significantly positive progress; you will also note areas where I believe the Laboratory could make improvements. Overall, however, I believe you will be quite pleased to note that we have maintained, or exceeded, the high standards of performance we have set for the Laboratory.
Date: November 5, 1999
Creator: LaBarge, Randy R.
Object Type: Report
System: The UNT Digital Library
Chemiluminescence assay for the detection of biological warfare agents (open access)

Chemiluminescence assay for the detection of biological warfare agents

A chemiluminescent homogeneous immunoassay and a hand-size multiassay reader are described that could be used for detecting biological materials. The special feature of the assay is that it employs two different antibodies that each bind to a unique epitope on the same antigen. Each group of epitope-specific antibodies has linked to it an enzyme of a proximal-enzyme pair. One enzyme of the pair utilizes a substrate in high concentration to produce a second substrate required by the second enzyme. This new substrate enables the second enzyme to function. The reaction of the second enzyme is configured to produce light. This chemiluminescence is detected with a charge-coupled device (CCD) camera. The proximal pair enzymes must be in close proximity to one another to allow the second enzyme to react with the product of the first enzyme. This only occurs when the enzyme-linked antibodies are attached to the antigen, whether antigen is a single protein with multiple epitopes or the surface of a cell with a variety of different antigens. As a result of their juxtaposition, the enzymes produce light only in the presence of the biological material. A brief description is given as to how this assay could be utilized in …
Date: November 5, 1999
Creator: Langry, K & Horn, J
Object Type: Report
System: The UNT Digital Library
Interface Control Document between the Double Shell Tanks (DST) System and T Plant (open access)

Interface Control Document between the Double Shell Tanks (DST) System and T Plant

This Interface Control Document (ICD) describes the interface between the Double-Shell Tank (DST) System and T Plant. T Plant generates waste during decontamination activities. These facilities do not have a direct physical interface since the waste will be moved by tank trailer to the 204-AR waste unloading facility. The purpose of the ICD process is to formalize working agreements between the River Protection Project (WP) DST System and organization/companies internal and external to RPP. This ICD has been developed as part of the requirements basis for design of the DST System to support the Phase I Privatization effort.
Date: November 5, 1999
Creator: MAY, T.H.
Object Type: Report
System: The UNT Digital Library
Cost analysis of NOx control alternatives for stationary gas turbines (open access)

Cost analysis of NOx control alternatives for stationary gas turbines

The use of stationary gas turbines for power generation has been growing rapidly with continuing trends predicted well into the future. Factors that are contributing to this growth include advances in turbine technology, operating and siting flexibility and low capital cost. Restructuring of the electric utility industry will provide new opportunities for on-site generation. In a competitive market, it maybe more cost effective to install small distributed generation units (like gas turbines) within the grid rather than constructing large power plants in remote locations with extensive transmission and distribution systems. For the customer, on-site generation will provide added reliability and leverage over the cost of purchased power One of the key issues that is addressed in virtually every gas turbine application is emissions, particularly NO{sub x} emissions. Decades of research and development have significantly reduced the NO{sub x} levels emitted from gas turbines from uncontrolled levels. Emission control technologies are continuing to evolve with older technologies being gradually phased-out while new technologies are being developed and commercialized. The objective of this study is to determine and compare the cost of NO{sub x} control technologies for three size ranges of stationary gas turbines: 5 MW, 25 MW and 150 MW. The …
Date: November 5, 1999
Creator: Major, Bill
Object Type: Report
System: The UNT Digital Library
Photon Beam Diagnostics for VISA FEL (open access)

Photon Beam Diagnostics for VISA FEL

The VISA (Visible to Infrared SASE Amplifier) project is designed to be a SASE-FEL driven to saturation in the sub-micron wavelength region. Its goal is to test various aspects of the existing theory of Self-Amplified Spontaneous Emission, as well as numerical codes. Measurements include: angular and spectral distribution of the FEL light at the exit and inside of the undulator; electron beam micro-bunching using CTR; single-shot time resolved measurements of the pulse profile, using auto-correlation technique and FROG algorithm. The diagnostics are designed to provide maximum information on the physics of the SASE-FEL process, to ensure a close comparison of the experimental results with theory and simulations.
Date: November 5, 1999
Creator: Murokh, A.; Pellegrini, C.; Rosenzweig, J.; Frigola, P.; Musumeci, P.; Tremaine, A. et al.
Object Type: Article
System: The UNT Digital Library
Sampling and Analysis Plan for Catch Tank 241ER311 Vapor (open access)

Sampling and Analysis Plan for Catch Tank 241ER311 Vapor

This tank sampling and analysis plan (TSAP) identifies the sample collection, laboratory analysis, quality assurance/quality control (QA/QC) objectives for the characterization of catch tank 241-ER-311 vapor space.
Date: November 5, 1999
Creator: NGUYEN, D.M.
Object Type: Report
System: The UNT Digital Library
Evaluation of Crystalline Silicotitanate and Self-Assembled Monolayers on Mesoporous Support for Cesium and Mercury Removal from DWPF Recycle (open access)

Evaluation of Crystalline Silicotitanate and Self-Assembled Monolayers on Mesoporous Support for Cesium and Mercury Removal from DWPF Recycle

The affinities for cesium and mercury ions contained in DWPF recycle simulants and Tank-22H waste have been evaluated using Crystalline Silicotitanate (CST) and Self-Assembled Monolayers on Mesoporous Support (SAMMS) ion-exchange materials, respectively. Results of the performance evaluations of CST on the uptake of cesium with simulants and actual DWPF recycle samples (Tank 22H) indicate that, in practice, this inorganic ion-exchange material can be used to remove radioactive cesium from the DWPF recycle. SAMMS material showed little or no affinity for mercury from highly alkaline DWPF waste. However, at near neutral conditions (DWPF simulant solution pH adjusted to 7), SAMMS was found to have a significant affinity for mercury. Conventional Duolite/256 ion exchange material showed an increase in affinity for mercury with increase in DWPF recycle simulant pH. Duolite/256 GT-73 also had a high batch distribution coefficient for mercury uptake from actual Tank 22H waste.
Date: November 5, 1999
Creator: Oji, L.N.
Object Type: Report
System: The UNT Digital Library
Dose Calculations for the Codsiposal WP of HLW Glass and the Shippingport LWBR SNF (open access)

Dose Calculations for the Codsiposal WP of HLW Glass and the Shippingport LWBR SNF

The purpose of this calculation is to determine the surface dose rates of a codisposal waste package (WP) containing an intact seed assembly of the Shippingport light-water breeder reactor (LWBR) spent nuclear fuel (SNF) and the Savannah River Site (SRS) high-level waste (HLW) in glass form. The Shippingport LWBR SNF is loaded in a Department of Energy (DOE) standardized 18-in. canister. The canister is surrounded by five 4.5-m-long Hanford pour canisters containing the HLW glass. Gamma dose rate calculation for the WP containing only the HLW glass is also performed. The results will provide information about the contribution of DOE SNF to the total dose rate on the WP surfaces.
Date: November 5, 1999
Creator: Radulescu, G.
Object Type: Report
System: The UNT Digital Library
MONITORED GEOLOGIC REPOSITORY INTERNAL HAZARDS ANALYSIS (open access)

MONITORED GEOLOGIC REPOSITORY INTERNAL HAZARDS ANALYSIS

This analysis was performed by the Management and Operating Contractor (M&amp;O) Safety Assurance Department to identify and document the internal hazards and preliminary events associated with preclosure operations of the Monitored Geologic Repository (MGR). Internal hazards are those hazards presented by operation of the facility and associated processes. These are in contrast to external hazards which involve natural phenomena and external man-made hazards. The hazard analysis methodology used in this analysis provides a systematic means to identify facility hazards and associated events that may result in radiological consequences to the public and facility worker during the MGR preclosure period. The events are documented in a preliminary events list and are intended to be used as input to the MGR Design Basis Event (DBE) selection process. It is expected that the results from this analysis will undergo further screening and analysis based on the criteria that apply to the performance of DBE analyses for the preclosure period of repository operation. As the MGR design progresses, this analysis will be reviewed to ensure no new hazards are introduced and that previously evaluated hazards have not increased in severity.
Date: November 5, 1999
Creator: Salzman, Scott E.
Object Type: Report
System: The UNT Digital Library
Tank 241ER311 Interconnected Piping and Equipment Vapor Sampling and Analysis Plan (open access)

Tank 241ER311 Interconnected Piping and Equipment Vapor Sampling and Analysis Plan

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained from piping, equipment, or facilities connected to tank 241-ER-311. The purpose of this sampling event is to obtain information about the effects of the argon purge gas added to tank 241-ER-311. Vapor samples will be taken in the encasement of transfer lines, at the ER-151 diversion box, and, as necessary, any other locations connected to tank 241-ER-311. Combustible gas, ammonia, and organic vapor levels will be field-measured using hand-held instruments. Vapor samples will be taken and shipped to the Pacific Northwest National Laboratory (PNNL) for analysis. This test plan identifies the sample collection, laboratory analysis, quality assurance, and reporting objectives for this data collection effort. The plan also provides the requirements for vapor measurements performed in the field.
Date: November 5, 1999
Creator: Sasaki, L. M.
Object Type: Report
System: The UNT Digital Library
Establishment of Harrop, High-Temperature Viscometer (open access)

Establishment of Harrop, High-Temperature Viscometer

This report explains how the Harrop, High-Temperature Viscometer was installed, calibrated, and operated. This report includes assembly and alignment of the furnace, viscometer, and spindle, and explains the operation of the Brookfield Viscometer, the Harrop furnace, and the UDC furnace controller. Calibration data and the development of the spindle constant from NIST standard reference glasses is presented. A simple operational procedure is included.
Date: November 5, 1999
Creator: Schumacher, R. F.
Object Type: Report
System: The UNT Digital Library
Alignment tolerances of IR quadrupoles in the LHC (open access)

Alignment tolerances of IR quadrupoles in the LHC

Luminosity in the LHC will depend critically on the alignment of the triplet quadrupoles. These quadrupoles are closest to the interaction points (IPs), have large gradients and the {beta} functions have their largest values within these quadrupoles. Within a triplet, the cold masses of the Q1 and Q3 quadrupoles will be housed in separate cryostats while Q2a and Q2b will be placed in a single cryostat. The absolute alignments of Q1, Q3 and the Q2a/Q2b pair with respect to the desired axes will be determined during installation. The relative alignment of Q2a and Q2b however will be fixed once they are placed in their common cryostat at Fermilab. In this note, we examine the required relative alignment tolerances of Q2a and Q2b. An early study of some alignment tolerances was done by Weisz [1].
Date: November 5, 1999
Creator: Sen, Tanaji
Object Type: Article
System: The UNT Digital Library
Qualitative Macroinvertebrate Assessment of Crouch Branch, June 1999 (open access)

Qualitative Macroinvertebrate Assessment of Crouch Branch, June 1999

An assessment of the macroinvertebrate community of Crouch Branch was performed in June 1999 to determine if effluent from the H-02 outfall is impairing the quality of the stream. Concurrent samples were collected for metals analyses (copper and zinc). The results of the study indicate that the stream is most impaired just downstream from the H-02 outfall and that the quality of the stream biota improves with increasing distance from the outfall. Conversely, macroinvertebrate habitat quality is best just downstream from the H-02 outfall. The midreaches of the stream contain very poor habitat quality, and the lower reaches of the stream, contain habitat of intermediate quality. Although much of the stream has degraded habitat due to channel erosion and scouring, there is strong evidence to suggest that the impairment is due to elevated concentrations of copper and zinc that are present in the H-02 effluent. A comparison of macroinvertebrate data collected in 1997 to the data collected in this study indicates that the macroinvertebrate community of Crouch Branch has improved markedly in the last two years.
Date: November 5, 1999
Creator: Specht, Winona L.
Object Type: Report
System: The UNT Digital Library