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Radiological Scoping Survey of the Scotia Depot, Scotia, NY (open access)

Radiological Scoping Survey of the Scotia Depot, Scotia, NY

The objectives of the radiological scoping survey were to collect adequate field data for use in evaluating the radiological condition of Scotia Depot land areas, warehouses, and support buildings.
Date: February 25, 2008
Creator: Bailey, E. N.
Object Type: Report
System: The UNT Digital Library
A derivation of the Pn reduction factors for a spherical hohlraum (open access)

A derivation of the Pn reduction factors for a spherical hohlraum

None
Date: February 25, 2008
Creator: Chang, B.
Object Type: Report
System: The UNT Digital Library
PROBABILISTIC SENSITIVITY AND UNCERTAINTY ANALYSIS WORKSHOP SUMMARY REPORT (open access)

PROBABILISTIC SENSITIVITY AND UNCERTAINTY ANALYSIS WORKSHOP SUMMARY REPORT

Stochastic or probabilistic modeling approaches are being applied more frequently in the United States and globally to quantify uncertainty and enhance understanding of model response in performance assessments for disposal of radioactive waste. This increased use has resulted in global interest in sharing results of research and applied studies that have been completed to date. This technical report reflects the results of a workshop that was held to share results of research and applied work related to performance assessments conducted at United States Department of Energy sites. Key findings of this research and applied work are discussed and recommendations for future activities are provided.
Date: June 25, 2008
Creator: Seitz, R
Object Type: Report
System: The UNT Digital Library
On the Relationship between Stress and Elastic Strain for Porous and Fractured Rock (open access)

On the Relationship between Stress and Elastic Strain for Porous and Fractured Rock

Modeling the mechanical deformations of porous and fractured rocks requires a stress-strain relationship. Experience with inherently heterogeneous earth materials suggests that different varieties of Hook's law should be applied within regions of the rock having significantly different stress-strain behavior, e.g., such as solid phase and various void geometries. We apply this idea by dividing a rock body conceptually into two distinct parts. The natural strain (volume change divided by rock volume at the current stress state), rather than the engineering strain (volume change divided by the unstressed rock volume), should be used in Hooke's law for accurate modeling of the elastic deformation of that part of the pore volume subject to a relatively large degree of relative deformation (i.e., cracks or fractures). This approach permits the derivation of constitutive relations between stress and a variety of mechanical and/or hydraulic rock properties. We show that the theoretical predictions of this method are generally consistent with empirical expressions (from field data) and also laboratory rock experimental data.
Date: February 25, 2008
Creator: Liu, Hui-Hai; Rutqvist, Jonny & Berryman, James G.
Object Type: Article
System: The UNT Digital Library
Design, Synthesis and Study of Dendrimers as Nanoscaffolds for Solar Energy Harvest (open access)

Design, Synthesis and Study of Dendrimers as Nanoscaffolds for Solar Energy Harvest

Designing molecules in which the vectorial motions of charges can be controlled has been of significant research interest in the recent past. Covalent linear arrays of chromophores or other molecular assemblies such as liquid crystals, zeolites, polymers, peptides, and amphiphiles have all been used as components for this purpose. Significant amount of this effort also involved the use of dendrimers as the molecular architecture. The structural feature in which multiple functionalities are present in the periphery that decreases gradually as one moves towards the core renders dendrimers obvious candidates for light harvesting antenna. Most of the efforts reported in the literature are directed towards energy funneling from a chromophore in the periphery to another chromophore at the core of the dendrimer. There are relatively few reports that utilize the dendritic architecture for photoinduced charge separation, an important step in designing materials for photovoltaics. These reports focus mostly on conjugated molecular backbones. Since non-conjugated dendrimer backbones provide the possibility of independently tuning the electronic characteristics of the chromophore and the charge transfer unit and therefore carry out a systematic structure-property relationship study, we have designed and synthesized dendrimers.
Date: January 25, 2008
Creator: Thayumanavan, Sankaran
Object Type: Report
System: The UNT Digital Library
Application Of Chiral Two- And Three-Nucleon Interactions To The 4He Photo-Disintegration (open access)

Application Of Chiral Two- And Three-Nucleon Interactions To The 4He Photo-Disintegration

We report on an ab initio calculation of the {sup 4}He total photo-absorption cross section using two- and three-nucleon interactions based upon chiral effective field theory. The microscopic treatment of the continuum problem is achieved using the Lorentz integral transform method, applied within the no-core shell model approach.
Date: January 25, 2008
Creator: Quaglioni, S & Navratil, P
Object Type: Article
System: The UNT Digital Library
Digitally Controlled High Availability Power Supply (open access)

Digitally Controlled High Availability Power Supply

This paper reports the design and test results on novel topology, high-efficiency, and low operating temperature, 1,320-watt power modules for high availability power supplies. The modules permit parallel operation for N+1 redundancy with hot swap capability. An embedded DSP provides intelligent start-up and shutdown, output regulation, general control and fault detection. PWM modules in the DSP drive the FET switches at 20 to 100 kHz. The DSP also ensures current sharing between modules, synchronized switching, and soft start up for hot swapping. The module voltage and current have dedicated ADCs (>200 kS/sec) to provide pulse-by-pulse output control. A Dual CAN bus interface provides for low cost redundant control paths. Over-rated module components provide high reliability and high efficiency at full load. Low on-resistance FETs replace conventional diodes in the buck regulator. Saturable inductors limit the FET reverse diode current during switching. The modules operate in a two-quadrant mode, allowing bipolar output from complimentary module groups. Controllable, low resistance FETs at the input and output provide fault isolation and allow module hot swapping.
Date: September 25, 2008
Creator: MacNair, David
Object Type: Article
System: The UNT Digital Library
Verification Survey of Rooms 113, 114, and 208 of the Inhalation Toxicology Laboratory, Lovelace Respiratory Research Institute, Albuquerque, NM (open access)

Verification Survey of Rooms 113, 114, and 208 of the Inhalation Toxicology Laboratory, Lovelace Respiratory Research Institute, Albuquerque, NM

The objectives of the verification survey were to confirm that accessible surfaces of the three laboratories meet the DOE’s established criteria for residual contamination. Drain pipes and ductwork were not included within the survey scope.
Date: June 25, 2008
Creator: Vitkus, T. J.
Object Type: Report
System: The UNT Digital Library
Electron-Cloud Build-Up Simulations for the FNAL Main Injector (open access)

Electron-Cloud Build-Up Simulations for the FNAL Main Injector

None
Date: August 25, 2008
Creator: Furman, Miguel A.
Object Type: Article
System: The UNT Digital Library
Identification and Assessment of Recent Aging-Related Degradation Occurrences in U.S. Nuclear Power Plants (open access)

Identification and Assessment of Recent Aging-Related Degradation Occurrences in U.S. Nuclear Power Plants

None
Date: November 25, 2008
Creator: Nie,J.; Braverman, J.; Hofmayer, C.; Choun, Y-S.; Kim, M.K. & Choi, I-K.
Object Type: Report
System: The UNT Digital Library
Novel QCD Phenomena at Electron-Proton Colliders (open access)

Novel QCD Phenomena at Electron-Proton Colliders

I discuss several novel phenomenological features of QCD which are observable in deep inelastic lepton-nucleon and lepton-nucleus scattering. Initial- and final-state interactions from gluon exchange, normally neglected in the parton model, have a profound effect on QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, the diffractive contribution to deep inelastic scattering, and the breakdown of the pQCD Lam-Tung relation in Drell-Yan reactions. Leading-twist diffractive processes in turn lead to nuclear shadowing and non-universal antishadowing--physics not incorporated in the light-front wavefunctions of the nucleus computed in isolation.
Date: July 25, 2008
Creator: Brodsky, Stanley J. & /SLAC /Durham U., IPPP
Object Type: Article
System: The UNT Digital Library
Radiological Studies for the LCLS Beam Abort System (open access)

Radiological Studies for the LCLS Beam Abort System

The Linac Coherent Light Source (LCLS), a pioneer hard x-ray free electron laser is currently under construction at the Stanford Linear Accelerator Center. It is expected that by 2009 LCLS will deliver laser pulses of unprecedented brightness and short length, which will be used in several forefront research applications. This ambitious project encompasses major design challenges to the radiation protection like the numerous sources and the number of surveyed objects. In order to sort those, the showers from various loss sources have been tracked along a detailed model covering 1/2 mile of LCLS accelerator by means of the Monte Carlo intra nuclear cascade codes FLUKA and MARS15. This article covers the FLUKA studies of heat load; prompt and residual dose and environmental impact for the LCLS beam abort system.
Date: March 25, 2008
Creator: Santana Leitner, M.; Vollaire, J. & Mao, X.S.
Object Type: Article
System: The UNT Digital Library
Joint reconstruction of CO2 plumes using disparate data (open access)

Joint reconstruction of CO2 plumes using disparate data

None
Date: February 25, 2008
Creator: Ramirez, A L & Friedmann, S J
Object Type: Report
System: The UNT Digital Library
Review of LLNS Contractor Assurance System (CAS) (open access)

Review of LLNS Contractor Assurance System (CAS)

The focus of the review was to evaluate the LLNS Contractor Assurance System (CAS) system description document and implementation plan. The team reviewed the description document and the near and long term strategy improvement plans for the defined enhancements to the LLNS CAS. Review emphasis was placed on the CAS functional elements of Assessments, Issues Management, and Performance Measures, as well as the related CAS attributes of Requirements, Policies and Procedures, Risk Methodology, and Continuous Improvement. The approach taken by the team was to review the pertinent LLNL CAS documents, interview key CAS Process Owners, and interview selected line managers. The reviews were conducted in such a manner to achieve an understanding of the overall objective of the CAS and the processes within; and the soundness of the improvement plans for each of the elements/related attributes. The team then identified suggested recommendations for consideration as the overall implementation process for improvements move forward. The team appreciates the work that went into the development of the CAS Implementation Plan. It provided a meaningful starting place for this AIM team as it included sufficient information to quickly gain an understanding of the current LANS CAS processes and improvement initiatives. The team found …
Date: January 25, 2008
Creator: Johnston, J.E.; Litus, M.; Metta, S. & Luce, W.
Object Type: Report
System: The UNT Digital Library
A Gridded Electron Gun for a Sheet Beam Klystron (open access)

A Gridded Electron Gun for a Sheet Beam Klystron

This paper describes the development of an electron gun for a sheet beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.
Date: April 25, 2008
Creator: Read, M. E.; Miram, G.; Ives, R. L.; Ivanov, V. & Krasnykh, A.
Object Type: Article
System: The UNT Digital Library
Timescales of spherulite crystallization in obsidian inferred from water concentration profiles (open access)

Timescales of spherulite crystallization in obsidian inferred from water concentration profiles

We determined the kinetics of spherulite growth in obsidians from Krafla volcano, Iceland. We measured water concentration profiles around spherulites in obsidian by synchrotron Fourier transform infrared spectroscopy. The distribution of OH? groups surrounding spherulites decreases exponentially away from the spherulite-glass border, reflecting expulsion of water during crystallization of an anhydrous paragenesis (plagioclase + SiO2 + clinopyroxene + magnetite). This pattern is controlled by a balance between the growth rate of the spherulites and the diffusivity of hydrous solute in the rhyolitic melt. We modeled advective and diffusive transport of the water away from the growing spherulites by numerically solving the diffusion equation with a moving boundary. Numerical models fit the natural data best when a small amount of post-growth diffusion is incorporated in the model. Comparisons between models and data constrain the average spherulite growth rates for different temperatures and highlight size-dependent growth among a small population of spherulites.
Date: June 25, 2008
Creator: Castro, Jonathan M.; Beck, Pierre; Tuffen, Hugh; Nichols, Alexander R.L.; Dingwell, Donald B. & Martin, Michael C
Object Type: Article
System: The UNT Digital Library
Redesign of the SNS Modulator H-Bridge for Utilization of Press-Pack IGBTs (open access)

Redesign of the SNS Modulator H-Bridge for Utilization of Press-Pack IGBTs

The power conversion group at SLAC is currently redesigning the H-bridge switch plates of the High Voltage Converter Modulators at the Spallation Neutron Source. This integral part to the modulator operation has been indentified as a source of several modulator faults and potentially limits reliability with pulse width modulation operation. This paper is a presentation of the design and implementation of a redesigned switch plate based upon press-pack IGBTs.
Date: September 25, 2008
Creator: Kemp, Mark A.; Burkhart, Craig & Anderson, David E.
Object Type: Article
System: The UNT Digital Library
Test Results of the AC Field Measurements of Fermilab Booster Corrector Magnets (open access)

Test Results of the AC Field Measurements of Fermilab Booster Corrector Magnets

Multi-element corrector magnets are being produced at Fermilab that enable correction of orbits and tunes through the entire cycle of the Booster, not just at injection. The corrector package includes six different corrector elements--normal and skew orientations of dipole, quadrupole, and sextupole--each independently powered. The magnets have been tested during typical AC ramping cycles at 15Hz using a fixed coil system to measure the dynamic field strength and field quality. The fixed coil is comprised of an array of inductive pick-up coils around the perimeter of a cylinder which are sampled simultaneously at 100 kHz with 24-bit ADC's. The performance of the measurement system and a summary of the field results are presented and discussed.
Date: June 25, 2008
Creator: DiMarco, E.Joseph; Harding, D. J.; Kashikhin, V. S.; Kotelnikov, S. K.; Lamm, M. J.; Makulski, A. et al.
Object Type: Article
System: The UNT Digital Library
PLUTONIUM-URANIUM EXTRACTION (PUREX) FACILITY ALARACT DEMONSTRATION FOR FILTER HOUSING (open access)

PLUTONIUM-URANIUM EXTRACTION (PUREX) FACILITY ALARACT DEMONSTRATION FOR FILTER HOUSING

This document presents an As Low As Reasonably Achievable Control Technology (ALARACT) demonstration for evaluating corrosion on the I-beam supporting filter housing No.9 for the 291-A-l emission unit of the Plutonium-Uranium Extraction (PUREX) Facility, located in the 200 East Area of the Hanford Site. The PUREX facility is currently in surveillance and maintenance mode. During a State of Washington, Department of Health (WDOH) 291-A-l emission unit inspection, a small amount of corrosion was observed at the base of a high-efficiency particulate air (HEPA) filter housing. A series of internal and external inspections identified the source of the corrosion material as oxidation of a small section of one of the carbon steel I-beams that provides support to the stainless steel filter housing. The inspections confirmed the corrosion is isolated to one I-beam support location and does not represent any compromise of the structural support or filter housing integrity. Further testing and inspections of the support beam corrosion and its cause were conducted but did not determine the cause. No definitive evidence was found to support any degradation of the housing. Although no degradation of the housing was found, a conservative approach will be implemented. The following actions will be taken: (1) …
Date: November 25, 2008
Creator: GJ, LEBARON
Object Type: Report
System: The UNT Digital Library
Radiochemical Solar Neutrino Experiments - Successful and Otherwise. (open access)

Radiochemical Solar Neutrino Experiments - Successful and Otherwise.

Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ({sup 37}Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ({sup 71}Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled.
Date: May 25, 2008
Creator: Hahn,R.L.
Object Type: Article
System: The UNT Digital Library
Standard Model Condensates and the Cosmological Constant (open access)

Standard Model Condensates and the Cosmological Constant

This paper suggests a solution to the problem of some apparently excessive contributions to the cosmological constant from Standard-Model condensates.
Date: March 25, 2008
Creator: Brodsky, Stanley J.; /SLAC /SUNY, Stony Brook; Shrock, Robert & /SUNY, Stony Brook
Object Type: Article
System: The UNT Digital Library
Study of Hadronic Transitions Between \Upsilon States and Observation of \Upsilon(4S) to\eta\Upsilon(1S) Decay (open access)

Study of Hadronic Transitions Between \Upsilon States and Observation of \Upsilon(4S) to\eta\Upsilon(1S) Decay

The authors present a study of hadronic transitions between {Upsilon}(mS) (m = 4,3,2) and {Upsilon}(nS) (n = 2,1) resonances based on 347.5 fb{sup -1} of data taken with the BABAR detector at the PEP-II storage rings.
Date: July 25, 2008
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Design and Commissioning Plan for a Laser Heater for FERMI@elettra (open access)

Design and Commissioning Plan for a Laser Heater for FERMI@elettra

The purpose of a laser heater is to increase the electron beam uncorrelated energy spread as a way to control and ideally suppress the microbunching instability in the linac drive for x-rays FELs. We review the motivations for equipping FERMI with a laser heater and provide a specification for the basics parameters as well as a description of a practical layout including desired diagnostics provisions for both the electron and laser beams. We also outline some useful operational guidelines for commissioning.
Date: October 25, 2008
Creator: Zholents, Alexander A.; Qiang, J.; Venturini, M.; Wells,, R.; Wilcox, R.; Di Mitri, S. et al.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF A NON-NOBLE METAL HYDROGEN PURIFICATION SYSTEM (open access)

DEVELOPMENT OF A NON-NOBLE METAL HYDROGEN PURIFICATION SYSTEM

Development of advanced hydrogen separation membranes in support of hydrogen production processes such as coal gasification and as front end gas purifiers for fuel cell based system is paramount to the successful implementation of a national hydrogen economy. Current generation metallic hydrogen separation membranes are based on Pd-alloys. Although the technology has proven successful, at issue is the high cost of palladium. Evaluation of non-noble metal based dense metallic separation membranes is currently receiving national and international attention. The focus of the reported work was to develop a scaled reactor with a VNi-Ti alloy membrane to replace a production Pd-alloy tube-type purification/diffuser system.
Date: November 25, 2008
Creator: Korinko, P; Kyle Brinkman, K; Thad Adams, T & George Rawls, G
Object Type: Article
System: The UNT Digital Library