NEUTRON ACTIVATION ANALYSIS APPLICATIONS AT THE SAVANNAH RIVER SITE USING AN ISOTOPIC NEUTRON SOURCE (open access)

NEUTRON ACTIVATION ANALYSIS APPLICATIONS AT THE SAVANNAH RIVER SITE USING AN ISOTOPIC NEUTRON SOURCE

NAA using {sup 252}Cf is used to address important areas of applied interest at SRS. Sensitivity needs for many of the applications are not severe; analyses are accomplished using a 21 mg {sup 252}Cf NAA facility. Because NAA allows analysis of bulk samples, it offers strong advantages for samples in difficult-to-digest matrices when its sensitivity is sufficient. Following radiochemical separation with stable carrier addition, chemical yields for a number methods are determined by neutron activation of the stable carrier. In some of the cases where no suitable stable carriers exist, the source has been used to generate radioactive tracers to yield separations.
Date: August 14, 2006
Creator: Diprete, D; C Diprete, C & Raymond Sigg, R
Object Type: Article
System: The UNT Digital Library
Niobium Oxide-Metal Based Seals for High Temperature Applications (open access)

Niobium Oxide-Metal Based Seals for High Temperature Applications

The present final report describes technical progress made in regards to evaluating niobium oxide/alumina as a high temperature seal material. Fabrication and characterization of specimens comprising niobium oxide and alumina composites of various compositions was performed. The goal was to identify regions where a glass formed. There were no experimental conditions where a glassy phase was unequivocally identified. However, the results led to the formation of an interesting class of fibrous composites which may have applications where high compliance and high toughness are needed. It is clear that vapor phase sintering is an active mass transport mechanism in Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} composites (Figure 1), and it may be possible to design porous materials by utilizing vapor phase sintering. The compositions evaluated in the present work are 52, 60, 73, 82 and 95 mol. % Nb{sub 2}O{sub 5} with the remainder Al{sub 2}O{sub 3}. These were chosen so that some eutectic composition was present during cooling, in an attempt to encourage glass formation. However, the presence of large, elongated crystals, both in the slow cool and the quench experiments indicates that the driving force for crystallization is very high. Several joints were formed between high purity alumina with two …
Date: August 14, 2006
Creator: Reimanis, Ivar
Object Type: Report
System: The UNT Digital Library
The Radiation Dose Measurement System for the BaBar Electromagnetic Calorimeter (open access)

The Radiation Dose Measurement System for the BaBar Electromagnetic Calorimeter

An array of 116 p-channel radiation sensitive MOSFET transistors (RadFETs) has been operational for the past 6 years at the BaBar experiment at the PEP-II asymmetric B-Factory at the Stanford Linear Accelerator Center (SLAC). This system maps the integrated dose absorbed by different regions of the Electromagnetic Calorimeter (EMC) during the running of the experiment. We report on the design and implementation of the system and finally, the performance of the monitoring system during the last 6 years of BaBar data-taking.
Date: August 14, 2006
Creator: Khan, A.; U., /Brunel; Meyer, W.T.; U., /Iowa State; Stelzer, J.; /Stanford U., Phys. Dept. et al.
Object Type: Article
System: The UNT Digital Library
Grid Application for the BaBar Experiment (open access)

Grid Application for the BaBar Experiment

This paper discusses the use of e-Science Grid in providing computational resources for modern international High Energy Physics (HEP) experiments. We investigate the suitability of the current generation of Grid software to provide the necessary resources to perform large-scale simulation of the experiment and analysis of data in the context of multinational collaboration.
Date: August 14, 2006
Creator: Khan, A.; U., /Brunel; Wilson, F. & /Rutherford
Object Type: Article
System: The UNT Digital Library
Time-resolved Temperature Measurements in SSPX (open access)

Time-resolved Temperature Measurements in SSPX

We seek to measure time-resolved electron temperatures in the SSPX plasma using soft X-rays from free-free Bremsstrahlung radiation. To increase sensitivity to changes in temperature over the range 100-300 eV, we use two photodiode detectors sensitive to different soft X-ray energies. The detectors, one with a Zr/C coating and the other with a Ti/Pd coating, view the plasma along a common line of sight tangential to the magnetic axis of the spheromak, where the electron temperature is a maximum. The comparison of the signals, over a similar volume of plasma, should be a stronger function of temperature than a single detector in the range of Te< 300 eV. The success of using photodiodes to detect changing temperatures along a chord will make the case for designing an array of the detectors, which could provide a time changing temperature profile over a larger portion of the plasma.
Date: August 14, 2006
Creator: Ludington, A. R.; Hill, D. N.; McLean, H. S.; Moller, J. & Wood, R. D.
Object Type: Report
System: The UNT Digital Library
Measurement of cross sections for alpha-induced reactions on 197Au and thick-target yields for the ((alpha),(gamma)) process on 64Zn and 63Cu (open access)

Measurement of cross sections for alpha-induced reactions on 197Au and thick-target yields for the ((alpha),(gamma)) process on 64Zn and 63Cu

We have measured the cross sections for the {sup 197}Au({alpha},{gamma}){sup 201}Tl and {sup 197}Au({alpha},2n){sup 199}Tl reactions in the 17.9- to 23.9-MeV energy range, and {sup 197}Au({alpha},n){sup 200}Tl reaction in the 13.4- to 23.9-MeV energy range using an activation technique. Thick-target yields for the {sup 64}Zn({alpha},{gamma}){sup 68}Ge (7- to 14-MeV) and {sup 63}Cu({alpha},{gamma}){sup 67}Ga (7-MeV) reactions were measured. For all measurements, natural elements were bombarded with He{sup +} beams from the 88'' Cyclotron at the Lawrence Berkeley National Laboratory (LBNL). Irradiated samples were counted using a g-spectrometry system at LBNL's Low Background Facility. Measured {sup 197}Au({alpha},{gamma}){sup 201}Tl cross-sections were compared with the NON-SMOKER theoretical values. The thick-target yields for the {sup 64}Zn({alpha},{gamma}){sup 68}Ge and {sup 63}Cu({alpha},{gamma}){sup 67}Ga reactions are also compared with the theoretical yield, calculated numerically using the energy dependent NON-SMOKER cross section data. In both cases, measured values are found to follow a trend of overlapping the predicted value near the alpha nucleus barrier height and fall below with a slowly widening difference between them in the sub barrier energy points.
Date: August 14, 2006
Creator: Basunia, M. S.; Shugart, H. A.; Smith, A. R. & Norman, E. B.
Object Type: Article
System: The UNT Digital Library
Geostatistical and Stochastic Study of Flow and Transport in the Unsaturated Zone at Yucca Mountain (open access)

Geostatistical and Stochastic Study of Flow and Transport in the Unsaturated Zone at Yucca Mountain

Yucca Mountain has been proposed by the U.S. Department of Energy as the nation’s long-term, permanent geologic repository for spent nuclear fuel or high-level radioactive waste. The potential repository would be located in Yucca Mountain’s unsaturated zone (UZ), which acts as a critical natural barrier delaying arrival of radionuclides to the water table. Since radionuclide transport in groundwater can pose serious threats to human health and the environment, it is important to understand how much and how fast water and radionuclides travel through the UZ to groundwater. The UZ system consists of multiple hydrogeologic units whose hydraulic and geochemical properties exhibit systematic and random spatial variation, or heterogeneity, at multiple scales. Predictions of radionuclide transport under such complicated conditions are uncertain, and the uncertainty complicates decision making and risk analysis. This project aims at using geostatistical and stochastic methods to assess uncertainty of unsaturated flow and radionuclide transport in the UZ at Yucca Mountain. Focus of this study is parameter uncertainty of hydraulic and transport properties of the UZ. The parametric uncertainty arises since limited parameter measurements are unable to deterministically describe spatial variability of the parameters. In this project, matrix porosity, permeability and sorption coefficient of the reactive tracer …
Date: August 14, 2007
Creator: Ye, Ming; Pan, Feng; Hu, Xiaolong & Zhu, Jianting
Object Type: Report
System: The UNT Digital Library
Air Convection Noise of Pencil-Beam Interfermeter for Long Trace Profiler (open access)

Air Convection Noise of Pencil-Beam Interfermeter for Long Trace Profiler

In this work, we investigate the effect of air convection on laser-beam pointing noise essential for the long trace profiler (LTP). We describe this pointing error with noise power density (NPD) frequency distributions. It is shown that the NPD spectra due to air convection have a very characteristic form. In the range of frequencies from {approx}0.05 Hz to {approx}0.5 Hz, the spectra can be modeled with an inverse-power-law function. Depending on the intensity of air convection that is controlled with a resistive heater of 100 to 150 mW along a one-meter-long optical path, the power index lies between 2 and 3 at an overall rms noise of {approx}0.5 to 1 microradian. The efficiency of suppression of the convection noise by blowing air across the beam optical path is also discussed. Air-blowing leads to a white-noise-like spectrum. Air blowing was applied to the reference channel of an LTP allowing demonstration of the contribution of air convection noise to the LTP reference beam. The ability to change (with the blowing technique presented) the spectral characteristics of the beam pointing noise due to air convection allows one to investigate the contribution of the convection effect, and thus make corrections to the power spectral …
Date: August 14, 2006
Creator: Yashchuk, V. V.; Irick, S. C.; MacDowell, A. A.; McKinney, W. R. & Takacs, P. Z.
Object Type: Article
System: The UNT Digital Library
Technical Challenges for the Head-on Collisions and Extraction at the ILC (open access)

Technical Challenges for the Head-on Collisions and Extraction at the ILC

An interaction region with head-on collisions is considered as an alternative to the baseline ILC configuration. Progress in the final focus optics design includes engineered large bore superconducting final doublet magnets and their 3D magnetic integration in the detector solenoids. Progress on the beam separation optics is based on technical designs of electrostatic separator and special extraction quadrupoles. The spent beam extraction is realized by a staged collimation scheme relying on realistic collimators.
Date: August 14, 2007
Creator: Napoly, O.; Delferriere, O.; Durante, M.; Payet, J.; Rippon, C.; Uriot, D. et al.
Object Type: Article
System: The UNT Digital Library
Design of the Beam Delivery System for the International Linear Collider (open access)

Design of the Beam Delivery System for the International Linear Collider

None
Date: August 14, 2007
Creator: Seryi, A.; Amann, J.; Arnold, R.; Asiri, F.; Bane, K.; Bellomo, P. et al.
Object Type: Article
System: The UNT Digital Library
MOSSFRAC: An anisotropic 3D fracture model (open access)

MOSSFRAC: An anisotropic 3D fracture model

Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by …
Date: August 14, 2006
Creator: Moss, W C & Levatin, J L
Object Type: Report
System: The UNT Digital Library
CALCULATION: PRECIPITATION CHARACTERISITICS FOR STORM WATER MANAGEMENT (open access)

CALCULATION: PRECIPITATION CHARACTERISITICS FOR STORM WATER MANAGEMENT

This Calculation is intended to satisfy engineering requirements for maximum 60-minute precipitation amounts for 50 and 100-year return periods at and near Yucca Mountain. This data requirement is documented in the ''Interface Control Document for Support Operations to Surface Facilities Operations Functional and Organizational Interfaces'' (CRWMS M&O 1998a). These developed data will supplement the information on 0.1 hour to 6-hour (in 0.1-hour increments) probable maximum precipitation (PMP) presented in the report, ''Precipitation Design Criteria for Storm Water Management'' (CRWMS M&O 1998b). The Reference Information Base (RIB) item, Precipitation ''Characteristics for Storm Water Management'' (M09902RIB00045 .OOO), was developed based on CRWMS M&O (1998b) and will be supplemented (via revision) with the information developed in this Calculation. The ''Development Plan for the Calculation: Precipitation Characteristics for Storm Water Management'' (CRWMS M&O 2000) was prepared in accordance with AP-2.l3Q, ''Technical Product Development Planning''. This calculation was developed in accordance with AP-3.12Q, Rev. O/ICN 2.
Date: August 14, 2000
Creator: Ambos, D.
Object Type: Report
System: The UNT Digital Library
Waste Management Quality Assurance Plan (open access)

Waste Management Quality Assurance Plan

The WMG QAP is an integral part of a management system designed to ensure that WMG activities are planned, performed, documented, and verified in a manner that assures a quality product. A quality product is one that meets all waste acceptance criteria, conforms to all permit and regulatory requirements, and is accepted at the offsite treatment, storage, and disposal facility. In addition to internal processes, this QA Plan identifies WMG processes providing oversight and assurance to line management that waste is managed according to all federal, state, and local requirements for waste generator areas. A variety of quality assurance activities are integral to managing waste. These QA functions have been identified in the relevant procedures and in subsequent sections of this plan. The WMG QAP defines the requirements of the WMG quality assurance program. These requirements are derived from Department of Energy (DOE) Order 414.1C, Quality Assurance, Contractor Requirements Document, the LBNL Operating and Assurance Program Plan (OAP), and other applicable environmental compliance documents. The QAP and all associated WMG policies and procedures are periodically reviewed and revised, as necessary, to implement corrective actions, and to reflect changes that have occurred in regulations, requirements, or practices as a result of …
Date: August 14, 2006
Creator: Group, Waste Management
Object Type: Report
System: The UNT Digital Library
EFRT M-12 Issue Resolution: Caustic Leach Rate Constants from PEP and Laboratory-Scale Tests (open access)

EFRT M-12 Issue Resolution: Caustic Leach Rate Constants from PEP and Laboratory-Scale Tests

Testing Summary Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed and constructed and is to be operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.” The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution …
Date: August 14, 2009
Creator: Mahoney, Lenna A.; Rassat, Scot D.; Eslinger, Paul W.; Aaberg, Rosanne L.; Aker, Pamela M.; Golovich, Elizabeth C. et al.
Object Type: Report
System: The UNT Digital Library
Development of High-Temperature Ferritic Alloys and Performance Prediction Methods for Advanced Fission Energy Systems (open access)

Development of High-Temperature Ferritic Alloys and Performance Prediction Methods for Advanced Fission Energy Systems

Reports the results of a comprehensive development and analysis of a database on irradiation hardening and embrittlement of tempered martensitic steels (TMS). Alloy specific quantitative semi-empirical models were derived for the dpa dose, irradiation temperature (ti) and test (Tt) temperature of yield stress hardening (or softening) .
Date: August 14, 2009
Creator: Odette, G. RObert & Yamamoto, Takuya
Object Type: Report
System: The UNT Digital Library
Handling Pyrophoric Reagents (open access)

Handling Pyrophoric Reagents

Pyrophoric reagents are extremely hazardous. Special handling techniques are required to prevent contact with air and the resulting fire. This document provides several methods for working with pyrophoric reagents outside of an inert atmosphere.
Date: August 14, 2009
Creator: Alnajjar, Mikhail S. & Haynie, Todd O.
Object Type: Report
System: The UNT Digital Library
Skyshine Contribution to Gamma Ray Background Between 0 and 4 MeV (open access)

Skyshine Contribution to Gamma Ray Background Between 0 and 4 MeV

Natural gamma-ray background is composed of four components; which include cosmic rays, cosmic ray produced atmospheric activity, terrestrial sources, and skyshine from terrestrial sources. Skyshine is radiation scattered from the air above a source that can produce a signal in radiation detection instrumentation. Skyshine has been studied for many years but its contribution to the natural background observed in a detector has not been studied. A large NaI(Tl) detector was used to investigate each of the four components of the natural background using a series of 48-hour measurements and appropriate lead shielding configured to discriminate contributions from each component. It was found that while the contribution from skyshine decreases rapidly with energy, it represents a significant portion of the background spectrum below ~500keV. A similar campaign of measurements using a HPGe detector is underway.
Date: August 14, 2009
Creator: Mitchell, Allison L.; Borgardt, James D. & Kouzes, Richard T.
Object Type: Report
System: The UNT Digital Library
Modeling Laser Effects on the Final Optics in Simulated IFE Environments (open access)

Modeling Laser Effects on the Final Optics in Simulated IFE Environments

When laser light interacts with a material's surface, photons rapidly heat the electronic system, resulting in very fast energy transfer to the underlying atomic crystal structure. The intense rate of energy deposition in the shallow sub-surface layer creates atomic defects, which alter the optical characteristics of the surface itself. In addition, the small fraction of energy absorbed in the mirror leads to its global deformation by thermal and gravity loads (especially for large surface area mirrors). The aim of this research was to model the deformation of mirror surfaces at multiple length and time scales for applications in advanced Inertial Fusion Energy (IFE) systems. The goal is to control micro- and macro-deformations by material system and structural design. A parallel experimental program at UCSD has been set up to validate the modeling efforts. The main objective of the research program was to develop computer models and simulations for Laser-Induced Damage (LID) in reflective and transmissive final optical elements in IFE laser-based systems. A range of materials and material concepts were investigated and verified by experiments at UCSD. Four different classes of materials were considered: (1) High-reflectivity FCC metals (e.g. Cu, Au, Ag, and Al), (2) BCC metals (e.g. Mo, Ta …
Date: August 14, 2004
Creator: Ghoniem, Nasr
Object Type: Report
System: The UNT Digital Library
The Advanced Light Source: A third-generation Synchrotron Radiation Source (open access)

The Advanced Light Source: A third-generation Synchrotron Radiation Source

The Advanced Light Source (ALS) at the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) of the University of California is a ''third-generation'' synchrotron radiation source optimized for highest brightness at ultraviolet and soft x-ray photon energies. It also provides world-class performance at hard x-ray photon energies. Berkeley Lab operates the ALS for the United States Department of Energy as a national user facility that is available 24 hours/day around the year for research by scientists from industrial, academic, and government laboratories primarily from the United States but also from abroad.
Date: August 14, 2002
Creator: Robinson, Arthur L.
Object Type: Article
System: The UNT Digital Library
Historical background: Why is it important to improve automated particle selection methods? (open access)

Historical background: Why is it important to improve automated particle selection methods?

A current trend in single-particle electron microscopy is to compute three-dimensional reconstructions with ever-increasing numbers of particles in the data sets. Since manual--or even semi-automated--selection of particles represents a major bottleneck when the data set exceeds several thousand particles, there is growing interest in developing automatic methods for selecting images of individual particles. Except in special cases, however, it has proven difficult to achieve the degree of efficiency and reliability that would make fully automated particle selection a useful tool. The simplest methods such as cross correlation (i.e., matched filtering) do not perform well enough to be used for fully automated particle selection. Geometric properties (area, perimeter-to-area ratio, etc.) and the integrated ''mass'' of candidate particles are additional factors that could improve automated particle selection if suitable methods of contouring particles could be developed. Another suggestion is that data be always collected as pairs of images, the first taken at low defocus (to capture information at the highest possible resolution) and the second at very high defocus (to improve the visibility of the particle). Finally, it is emphasized that well-annotated, open-access data sets need to be established in order to encourage the further development and validation of methods for automated …
Date: August 14, 2003
Creator: Glaeser, Robert M.
Object Type: Article
System: The UNT Digital Library
Alternative Field Methods to Treat Mercury in Soil (open access)

Alternative Field Methods to Treat Mercury in Soil

The Department of Energy (DOE) currently has mercury (Hg) contaminated materials and soils at the various sites. Figure 1-1 (from http://www.ct.ornl.gov/stcg.hg/) shows the estimated distribution of mercury contaminated waste at the various DOE sites. Oak Ridge and Idaho sites have the largest deposits of contaminated materials. The majorities of these contaminated materials are soils, sludges, debris, and waste waters. This project concerns treatment of mercury contaminated soils. The technology is applicable to many DOE sites, in-particular, the Y-12 National Security Complex in Oak Ridge Tennessee and Idaho National Engineering and Environmental Laboratory (INEEL). These sites have the majority of the soils and sediments contaminated with mercury. The soils may also be contaminated with other hazardous metals and radionuclides. At the Y12 plant, the baseline treatment method for mercury contaminated soil is low temperature thermal desorption (LTTD), followed by on-site landfill disposal. LTTD is relatively expensive (estimated cost of treatment which exclude disposal cost for the collect mercury is greater than $740/per cubic yard [cy] at Y-12), does not treat any of the metal or radionuclides. DOE is seeking a less costly alternative to the baseline technology. As described in the solicitation (DE-RA-01NT41030), this project initially focused on evaluating cost-effective in-situ …
Date: August 14, 2002
Creator: Stine, Ernie F.
Object Type: Report
System: The UNT Digital Library
Radiation load to the SNAP CCD (open access)

Radiation load to the SNAP CCD

Results of an express Monte Carlo analysis with the MARS14 code of radiation load to the CCD optical detectors in the Supernova Acceleration Project (SNAP) mission presented for realistic radiation environment over the satellite orbit.
Date: August 14, 2003
Creator: N. V. Mokhov, I. L. Rakhno and S. I. Striganov
Object Type: Report
System: The UNT Digital Library
The low-energy undulator test line : a SASE FEL operating from 660 to 130 nm. (open access)

The low-energy undulator test line : a SASE FEL operating from 660 to 130 nm.

None
Date: August 14, 2002
Creator: Biedron, S. G.; Borland, M.; Den Hartog, P.; Dejus, R.; Erdmann, M.; Huang, Z. et al.
Object Type: Article
System: The UNT Digital Library
Security for Grids (open access)

Security for Grids

Securing a Grid environment presents a distinctive set of challenges. This paper groups the activities that need to be secured into four categories: naming and authentication; secure communication; trust, policy, and authorization; and enforcement of access control. It examines the current state of the art in securing these processes and introduces new technologies that promise to meet the security requirements of Grids more completely.
Date: August 14, 2005
Creator: Humphrey, Marty; Thompson, Mary R. & Jackson, Keith R.
Object Type: Article
System: The UNT Digital Library