ENHANCED DOE HIGH LEVEL WASTE MELTER THROUGHPUT STUDIES: SRNL GLASS SELECTION STRATEGY (open access)

ENHANCED DOE HIGH LEVEL WASTE MELTER THROUGHPUT STUDIES: SRNL GLASS SELECTION STRATEGY

The Department of Energy has authorized a team of glass formulation and processing experts at the Savannah River National Laboratory (SRNL), the Pacific Northwest National Laboratory (PNNL), and the Vitreous State Laboratory (VSL) at Catholic University of America to develop a systematic approach to increase high level waste melter throughput (by increasing waste loading with minimal or positive impacts on melt rate). This task is aimed at proof-of-principle testing and the development of tools to improve waste loading and melt rate, which will lead to higher waste throughput. Four specific tasks have been proposed to meet these objectives (for details, see WSRC-STI-2007-00483): (1) Integration and Oversight, (2) Crystal Accumulation Modeling (led by PNNL)/Higher Waste Loading Glasses (led by SRNL), (3) Melt Rate Evaluation and Modeling, and (4) Melter Scale Demonstrations. Task 2, Crystal Accumulation Modeling/Higher Waste Loading Glasses is the focus of this report. The objective of this study is to provide supplemental data to support the possible use of alternative melter technologies and/or implementation of alternative process control models or strategies to target higher waste loadings (WLs) for the Defense Waste Processing Facility (DWPF)--ultimately leading to higher waste throughputs and a reduced mission life. The glass selection strategy discussed …
Date: January 23, 2008
Creator: Raszewski, F; Tommy Edwards, T & David Peeler, D
Object Type: Report
System: The UNT Digital Library
A Les Houches Interface for BSM Generators (open access)

A Les Houches Interface for BSM Generators

We propose to combine and slightly extend two existing 'Les Houches Accords' to provide a simple generic interface between beyond-the-standard-model parton-level and event-level generators. All relevant information--particle content, quantum numbers of new states, masses, cross sections, parton-level events, etc.--is collected in one single file, which adheres to the Les Houches Event File (LHEF) standard.
Date: January 23, 2008
Creator: Alwall, J.; Boos, E.; Dudko, L.; Gigg, M.; Herquet, M.; Pukhov, A. et al.
Object Type: Report
System: The UNT Digital Library
Response Time Measurements of the NIF DANTE XRD-31 X-Ray Diodes (Pre-print) (open access)

Response Time Measurements of the NIF DANTE XRD-31 X-Ray Diodes (Pre-print)

The XRD-31 is a fast, windowless X-ray vacuum photodiode developed by EG&G. It is currently the primary fast X-ray detector used to diagnose the X-rays on NIF and OMEGA on the multichannel DANTE spectrometer. The XRD-31 has a dynamic range of less than 1e-12 amps to more than 10 amps. A technique is described to measure the impulse response of the diodes to a 150 fs pulse of 200 nm laser light and a method to calculate the “risetime” for a square pulse and compare it with the computed electron transit time from the photocathode to the anode. Measured response time for 5 XRD-31s assembled in early 2004 was 149.7 ps +-2.75 ps.
Date: January 23, 2009
Creator: Griffin, Don Pellinen and Michael
Object Type: Article
System: The UNT Digital Library
Towards sub-10 nm resolution zone plates using the overlaynanofabrication processes (open access)

Towards sub-10 nm resolution zone plates using the overlaynanofabrication processes

Soft x-ray zone plate microscopy has proven to be a valuable imaging technique for nanoscale studies. It complements nano-analytic techniques such as electron and scanning probe microscopies. One of its key features is high spatial resolution. We developed an overlay nanofabrication process which allows zone plates of sub-20 nm zone widths to be fabricated. Zone plates of 15 nm outer zones were successfully realized using this process, and sub-15 nm resolution was achieved with these zone plates. We extend the overlay process to fabricating zone plates of 12 nm outer zones, which is expected to achieve 10 nm resolution. In addition, we have identified a pathway to realizing sub-10 nm resolution, high efficiency zone plates with tilted zones using the overlay process.
Date: January 23, 2008
Creator: Chao, Weilun; Anderson, Erik H.; Fischer, Peter & Kim, Dong-Hyun
Object Type: Article
System: The UNT Digital Library
Life Cost Based FMEA Manual: A Step by Step Guide to Carrying Out a Cost-based Failure Modes and Effects Analysis (open access)

Life Cost Based FMEA Manual: A Step by Step Guide to Carrying Out a Cost-based Failure Modes and Effects Analysis

Failure occurs when one or more of the intended functions of a product are no longer fulfilled to the customer's satisfaction. The most critical product failures are those that escape design reviews and in-house quality inspection and are found by the customer. The product may work for a while until its performance degrades to an unacceptable level or it may have not worked even before customer took possession of the product. The end results of failures which may lead to unsafe conditions or major losses of the main function are rated high in severity. Failure Modes and Effects Analysis (FMEA) is a tool widely used in the automotive, aerospace, and electronics industries to identify, prioritize, and eliminate known potential failures, problems, and errors from systems under design, before the product is released (Stamatis, 1997). Several industrial FMEA standards such as those published by the Society of Automotive Engineers, US Department of Defense, and the Automotive Industry Action Group employ the Risk Priority Number (RPN) to measure risk and severity of failures. The Risk Priority Number (RPN) is a product of 3 indices: Occurrence (O), Severity (S), and Detection (D). In a traditional FMEA process design engineers typically analyze the 'root …
Date: January 23, 2009
Creator: Rhee, Seung; Spencer, Cherrill & /SLAC, /Stanford U.
Object Type: Report
System: The UNT Digital Library
EMSL Fiscal Year 2008 Annual Report (open access)

EMSL Fiscal Year 2008 Annual Report

This annual report provides details on the research conducted at EMSL--the Environmental Molecular Sciences Laboratory in Fiscal Year 2008.
Date: January 23, 2009
Creator: Showalter, Mary Ann
Object Type: Report
System: The UNT Digital Library
Modeling of Fission Gas Release in UO2 (open access)

Modeling of Fission Gas Release in UO2

A two-stage gas release model was examined to determine if it could provide a physically realistic and accurate model for fission gas release under Prometheus conditions. The single-stage Booth model [1], which is often used to calculate fission gas release, is considered to be oversimplified and not representative of the mechanisms that occur during fission gas release. Two-stage gas release models require saturation at the grain boundaries before gas is release, leading to a time delay in release of gases generated in the fuel. Two versions of a two-stage model developed by Forsberg and Massih [2] were implemented using Mathcad [3]. The original Forsbers and Massih model [2] and a modified version of the Forsberg and Massih model that is used in a commercially available fuel performance code (FRAPCON-3) [4] were examined. After an examination of these models, it is apparent that without further development and validation neither of these models should be used to calculate fission gas release under Prometheus-type conditions. There is too much uncertainty in the input parameters used in the models. In addition. the data used to tune the modified Forsberg and Massih model (FRAPCON-3) was collected under commercial reactor conditions, which will have higher fission …
Date: January 23, 2006
Creator: Krohn, MH
Object Type: Report
System: The UNT Digital Library
Electron Bypass Line (EBL) Design: Electrons to A-line bypassing LCLS (open access)

Electron Bypass Line (EBL) Design: Electrons to A-line bypassing LCLS

Forty one years ago, September 20, 1966, the first beam entered End Station A, passed on through, and was terminated in Beam Dump East. This beam had an energy of 18.4 GeV, a record for the time. Since then, the SLAC ESA has been a mainstay facility for many high-energy physics and test beam experiments involving countless hours of data taking. Heretofore, it was assumed that with the completion and commissioning of the LCLS facility, beams from the main injector would no longer be available to this well equipped experimental facility. Fortunately, it has become clear that a bypass beamline design calling for modest modifications and using existing, soon to be surplus, components will enable continued utilization of this important facility.
Date: January 23, 2008
Creator: Fieguth, T. & Arnold, R.
Object Type: Report
System: The UNT Digital Library
CREEP STRAIN CORRELATION FOR IRRADIATED CLADDING (open access)

CREEP STRAIN CORRELATION FOR IRRADIATED CLADDING

In an attempt to predict the creep deformation of spent nuclear fuel cladding under the repository conditions, different correlations have been developed. One of them, which will be referred to as Murty's correlation in the following, and whose expression is given in Henningson (1998), was developed on the basis of experimental points related to unirradiated Zircaloy cladding (Henningson 1998, p. 56). The objective of this calculation is to adapt Murty's correlation to experimental points pertaining to irradiated Zircaloy cladding. The scope of the calculation is provided by the range of experimental parameters characterized by Zircaloy cladding temperature between 292 C and 420 C, hoop stress between 50 and 630 MPa, and test time extending to 8000 h. As for the burnup of the experimental samples, it ranges between 0.478 and 64 MWd/kgU (i.e., megawatt day per kilogram of uranium), but this is not a parameter of the adapted correlation.
Date: January 23, 2001
Creator: Macheret, P.
Object Type: Report
System: The UNT Digital Library
Measurements of the Propagation of EM Waves through the Vacuum Chamber of the PEP-II Low Energy Ring for Beam Diagnostics (open access)

Measurements of the Propagation of EM Waves through the Vacuum Chamber of the PEP-II Low Energy Ring for Beam Diagnostics

We present the results of our measurements of the electron cloud density in the PEP-II low energy ring (LER) by propagating a TE wave into the beam pipe. By connecting a signal generator to a beam position monitor button we can excite a signal above the vacuum chamber cut-off frequency and measure its propagation through the beam pipe with a spectrum analyzer connected to another button about 50 meters away. The measurement can be performed with different beam conditions and also at different settings of the solenoids used to reduce the build up of electrons. The presence of a modulation in the TE wave transmission, synchronous with the beam revolution frequency, which appear to increase in depth when the solenoids are switched off, seem to be directly correlated to the electron cloud density in the region between the two BPM's. In this paper we present and discuss the measurements taken in the Interaction Region 12 straight of the LER during 2006 and the first part of 2007.
Date: January 23, 2008
Creator: Byrd, John Michael; De Santis, S. & Pivi, MTF
Object Type: Article
System: The UNT Digital Library
An Instrument Design for the Accurate Determination of the Electron Beam Location in the Linac Coherent Light Source Undulator (open access)

An Instrument Design for the Accurate Determination of the Electron Beam Location in the Linac Coherent Light Source Undulator

The Linac Coherent Light Source (LCLS), currently under design, requires accurate alignment between the electron beam and each undulator's magnetic centerline. A beam finder wire (BFW) instrument has been developed to provide beam location information that is used to move the undulators to their appropriate positions. A BFW instrument is mounted at each of the 33 magnets in the undulator section. Beam detection is achieved by electrons impacting two carbon fiber wires and then sensing the downstream radiation. The wires are mounted vertically and horizontally on a wire card similar to that of a traditional wire scanner instrument. The development of the BFW presents several design challenges due to the need for high accuracy of the wires locations and the need for removal of the wires during actual operation of the LCLS (30 microns repeatability is required for the wire locations). In this paper, we present the technical specification, design criteria, mechanical design, and results from prototype tests for the BFW.
Date: January 23, 2008
Creator: Bailey, J. L.; Capatina, D.; Morgan, J. W. & Nuhn, H. D.
Object Type: Article
System: The UNT Digital Library
Application of Entry-Time Processes in Asset Management for Nuclear Power Plants (Final Report) (open access)

Application of Entry-Time Processes in Asset Management for Nuclear Power Plants (Final Report)

A mathematical model of entry-time processes was developed, and a computational method for solving that model was verified. This methodology was demonstrated via application to a succession of increasingly more complex subsystems of nuclear power plants. The effort culminated in the application to main generators that constituted the PhD dissertation of Shuwen (“Eric”) Wang. Dr. Wang is now employed by ABS Consulting, in Anaheim, CA. ABS is a principal provider to the nuclear industry of technical services related to reliability and safety.
Date: January 23, 2008
Creator: Nelson, Paul
Object Type: Report
System: The UNT Digital Library
Program Evaluation - Automotive Lightweighting Materials Program Research and Development Projects Assessment of Benefits - Case Studies No. 2 (open access)

Program Evaluation - Automotive Lightweighting Materials Program Research and Development Projects Assessment of Benefits - Case Studies No. 2

This report is the second of a series of studies to evaluate research and development (R&D) projects funded by the Automotive Lightweighting Materials (ALM) Program of the Office of Advanced Automotive Technologies (OAAT) of the U.S. Department of Energy (DOE). The objectives of the program evaluation are to assess short-run outputs and long-run outcomes that may be attributable to the ALM R&D projects. The ALM program focuses on the development and validation of advanced technologies that significantly reduce automotive vehicle body and chassis weight without compromising other attributes such as safety, performance, recyclability, and cost. Funded projects range from fundamental materials science research to applied research in production environments. Collaborators on these projects include national laboratories, universities, and private sector firms, such as leading automobile manufacturers and their suppliers. Three ALM R&D projects were chosen for this evaluation: Design and Product Optimization for Cast Light Metals, Durability of Lightweight Composite Structures, and Rapid Tooling for Functional Prototyping of Metal Mold Processes. These projects were chosen because they have already been completed. The first project resulted in development of a comprehensive cast light metal property database, an automotive application design guide, computerized predictive models, process monitoring sensors, and quality assurance methods. …
Date: January 23, 2003
Creator: Das, S.
Object Type: Report
System: The UNT Digital Library
Scalable Methods for Electronic Excitations and Optical Responses of Nanstructures: Mathematics to Algorithms to Observables (open access)

Scalable Methods for Electronic Excitations and Optical Responses of Nanstructures: Mathematics to Algorithms to Observables

This multi-investigator project was concerned with the development and application of new methods and computer codes that would allow realistic modeling of nanosystems. Carter's part in this team effort involved two method/algorithm/code development projects during the first 14 months of this grant. Carter's group has been advancing theory and applications of the orbital-free density functional theory (OF-DFT), the only DFT method that exhibits linear scaling for metals. Such a method offers the possibility of simulating large numbers of atoms with quantum mechanics, such that properties of metallic nanostructures (e.g. nanowires of realistic dimensions) could be investigated. In addition, her group has been developing and applying an embedded correlated wavefunction theory for treating localized excited states in condensed matter (including metals). The application of interest here is spin manipulation at the nanoscale, i.e., spintronics, in which local electron excitations interact with the surrounding material. Her embedded correlation method is ideal for studying such problems.
Date: January 23, 2009
Creator: Carter, Emily A.
Object Type: Report
System: The UNT Digital Library
[(eta5-PentamethylcyclopentadienylYb(III)(5,5'-dimethyl-2,2-bipyridyl)mu-OH)2(mu 2-trifluoromethylsulfanato-O,O')][tetraphenylborate](5,5'-dimethyl-2,2-bipyridyl) (open access)

[(eta5-PentamethylcyclopentadienylYb(III)(5,5'-dimethyl-2,2-bipyridyl)mu-OH)2(mu 2-trifluoromethylsulfanato-O,O')][tetraphenylborate](5,5'-dimethyl-2,2-bipyridyl)

The title compound C{sub 81}H{sub 88}BF{sub 3}N{sub 6}O{sub 5}SYb{sub 2}, crystallizes as a half-sandwich complex with a bridging inner-sphere trifluoro-methane sulfonate as well as two bridging hydroxide groups. there is uncoordinated 5,5{prime}-dimethyl-2,2{prime}-bipyridine in the crystal structure. The bound bipyridine ligands have N-C-C{prime}-n{prime} torsion angles of 12-13{sup o}. The triply bridged Yb centers are 3.5990(4) Angstroms apart. The Yb-N bonds range from 2.389(6)-2.424(5) Angstroms.
Date: January 23, 2008
Creator: Kazhdan, Daniel
Object Type: Article
System: The UNT Digital Library
Matter Dependence of the Three-Loop Soft Anomalous Dimension Matrix (open access)

Matter Dependence of the Three-Loop Soft Anomalous Dimension Matrix

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions, which has been computed through two loops. The two-loop matrix is proportional to the one-loop matrix. Recently there have been proposals that this proportionality extends to higher loops. One can test such proposals by computing the dependence of this matrix on the matter content in a generic gauge theory. It is shown that for the matter-dependent part the proportionality extends to three loops for arbitrary massless processes.
Date: January 23, 2009
Creator: Dixon, Lance J.
Object Type: Article
System: The UNT Digital Library
Design and Performance of the LCLS Cavity BPM System (open access)

Design and Performance of the LCLS Cavity BPM System

In this paper we present the design of the beam position monitor (BPM) system for the LCLS undulator, which features a high-resolution X-band cavity BPM. Each BPM has a TM{sub 010} monopole reference cavity and a TM{sub 110} dipole cavity designed to operate at a center frequency of 11.384 GHz. The signal processing electronics features a low noise single-stage three-channel heterodyne receiver that has selectable gain and a phase locking local oscillator. We will discuss the system specifications, design, and prototype test results.
Date: January 23, 2008
Creator: Lill, R. M.; Morrison, L. H.; Norum, W. E.; Sereno, N.; Waldschmidt, G. J.; Walters, D. R. et al.
Object Type: Article
System: The UNT Digital Library
Bootstrap Approximations in Contractor Renormalization (open access)

Bootstrap Approximations in Contractor Renormalization

None
Date: January 23, 2008
Creator: Siu, M.Stewart & Weinstein, Marvin
Object Type: Article
System: The UNT Digital Library
Polarized Photocathode R&D for Future Linear Collliders (open access)

Polarized Photocathode R&D for Future Linear Collliders

It is a challenge to generate full charge electrons from the electron sources without compromising polarization for the proposed ILC and CLIC. It is essential to advance polarized photocathodes to meet the requirements. SLAC has worldwide unique dedicated test facilities, Cathode Test System and dc-Gun Test Laboratory, to fully characterize polarized photocathodes. Recent systematic measurements on a strained-well InAlGaAs/AlGaAs cathode at the facilities show that 87% polarization and 0.3% QE are achieved. The QE can be increased to {approx}1.0% with atomic hydrogen cleaning. The surface charge limit at a very low current intensity and the clear dependence of the polarization on the surface charge limit are observed for the first time. On-going programs to develop photocathodes for the ILC and CLIC are briefly introduced.
Date: January 23, 2009
Creator: Zhou, F; Brachmann, A.; Maruyama, T. & Sheppard, J. C.
Object Type: Article
System: The UNT Digital Library
Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples (open access)

Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha and beta activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion with the relative bias being small compared to the dispersion. By also measuring environmental air sample filters simultaneously with electroplated alpha and beta sources, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations. Use of the current algorithm is therefore not recommended for assay applications and so use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha and beta activities on air sample filters (not due to radon progeny) around the 200 dpm level.
Date: January 23, 2009
Creator: Hayes, Robert
Object Type: Article
System: The UNT Digital Library
Determination of the b-quark Mass and Nonperturbative parameters in Semileptonic and Radiative Penguin Decays at BaBar (open access)

Determination of the b-quark Mass and Nonperturbative parameters in Semileptonic and Radiative Penguin Decays at BaBar

Knowing the mass of the b-quark is essential to the study of the structure and decays of B mesons as well as to future tests of the Higgs mechanism of mass generation. We present recent preliminary measurements of the b-quark mass and related nonperturbative parameters from moments of kinematic distributions in charmed and charmless semileptonic and radiative penguin B decays. Their determination from charmless semileptonic B decays is the first measurement in this mode. The data were collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -}-collider at the Stanford Linear Accelerator Center at a center-of-momentum energy of 10:58 GeV.
Date: January 23, 2008
Creator: Tackmann, Kerstin & collaboration, for the BABAR
Object Type: Article
System: The UNT Digital Library
Modeling of E-Cloud Build-Up in Grooved Vacuum Chambers using POSINST (open access)

Modeling of E-Cloud Build-Up in Grooved Vacuum Chambers using POSINST

Use of grooved vacuum chambers have been suggested as a way to limit electron cloud accumulation in the ILCDR. We report on simulations carried out using an augmented version of POSINST, accounting for e-cloud dynamics in the presence of grooves, and make contact with previous estimates of an effective secondary electron yield for grooved surfaces.
Date: January 23, 2008
Creator: Furman, Miguel A.; Vay, Jean-Luc; Venturini, M. & Pivi, M. T. F.
Object Type: Article
System: The UNT Digital Library
SUPPORT OF MSA AND GS SHORT COURSES AND THE COMPANION REVIEWS VOLUMES (open access)

SUPPORT OF MSA AND GS SHORT COURSES AND THE COMPANION REVIEWS VOLUMES

Report on two short courses: [1] Fluid-fluid Equilibria in the Crust: Petrology - Geochemistry - Economic potential. August 16-17, 2007 preceding the Goldschmidt Conference in Cologne, Germany) and [2] Paleoaltimetry: Geochemical And Thermodynamic Approaches. October 26-27, 2007 (preceding the GSA Annual Meeting in Denver, Colorado)
Date: January 23, 2008
Creator: Speer, J Alex
Object Type: Text
System: The UNT Digital Library
Gravitational Wave Detection with Atom Interferometry (open access)

Gravitational Wave Detection with Atom Interferometry

We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferometer presently under construction. The terrestrial experiment can operate with strain sensitivity {approx} 10{sup -19}/{radical}Hz in the 1 Hz-10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment probes the same frequency spectrum as LISA with better strain sensitivity {approx} 10{sup -20}/{radical}Hz. Each configuration compares two widely separated atom interferometers run using common lasers. The effect of the gravitational waves on the propagating laser field produces the main effect in this configuration and enables a large enhancement in the gravitational wave signal while significantly suppressing many backgrounds. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations and acceleration noise, and reduces spacecraft control requirements.
Date: January 23, 2008
Creator: Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC /Stanford U., Phys. Dept.; Hogan, Jason M.; Kasevich, Mark A. et al.
Object Type: Report
System: The UNT Digital Library