Resource Type

Pump Side-scattering in Ultra-powerful Backward Raman Amplifiers (open access)

Pump Side-scattering in Ultra-powerful Backward Raman Amplifiers

Extremely large laser power might be obtained by compressing laser pulses through backward Raman amplification (BRA) in plasmas. Premature Raman backscattering of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even as the desired amplification of the seed persists with a high efficiency. In this paper, we analyze side-scattering of laser pumps by plasma noise in backward Raman amplifiers. Though its growth rate is smaller than that of backscattering, the side-scattering can nevertheless be dangerous, because of a longer path of side-scattered pulses in plasmas and because of an angular dependence of the Raman resonance detuning. We show that side-scattering of laser pumps by plasma noise in BRA might be suppressed to a tolerable level at all angles by an appropriate combination of two detuning mechanisms associated with plasma density gradient and pump chirp.
Date: March 2, 2004
Creator: A.A. Solodov, V.M. Malkin, and N.J. Fisch
System: The UNT Digital Library
Development of An On-Line, Core Power Distribution Monitoring System (open access)

Development of An On-Line, Core Power Distribution Monitoring System

The objective of the proposed work was to develop a software package that can construct in three-dimensional core power distributions using the signals from constant temperature power sensors distributed in the reactor core. The software developed uses a mode-based state/parameter estmation technique that is particularly attractive when there are model uncertainties and/or large signal noise. The software yields the expected value of local power at the detector locations and points in between, as well as the probability distribution of the local power density
Date: October 2, 2007
Creator: ALdemir, Tunc; Miller, Don & Wang, Peng
System: The UNT Digital Library
Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components (open access)

Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components

Laser safety evaluation and output emission measurements were performed (during October and November 2001) on SNL MILES and Mini MILES laser emitting components. The purpose, to verify that these components, not only meet the Class 1 (eye safe) laser hazard criteria of the CDRH Compliance Guide for Laser Products and 21 CFR 1040 Laser Product Performance Standard; but also meet the more stringent ANSI Std. z136.1-2000 Safe Use of Lasers conditions for Class 1 lasers that govern SNL laser operations. The results of these measurements confirmed that all of the Small Arms Laser Transmitters, as currently set (''as is''), meet the Class 1 criteria. Several of the Mini MILES Small Arms Transmitters did not. These were modified and re-tested and now meet the Class 1 laser hazard criteria. All but one System Controllers (hand held and rifle stock) met class 1 criteria for single trigger pulls and all presented Class 3a laser hazard levels if the trigger is held (continuous emission) for more than 5 seconds on a single point target. All units were Class 3a for ''aided'' viewing. These units were modified and re-tested and now meet the Class 1 hazard criteria for both ''aided'' as well as ''unaided'' …
Date: February 2, 2002
Creator: AUGUSTONI, ARNOLD L.
System: The UNT Digital Library
Experimental Investigation of the Root Cause Mechanism and Effectiveness of Mitigating Actions for Axial Offset Anomaly in Pressurized Water Reactors (open access)

Experimental Investigation of the Root Cause Mechanism and Effectiveness of Mitigating Actions for Axial Offset Anomaly in Pressurized Water Reactors

Axial offset anomaly (AOA) in pressurized water reactors refers to the presence of a significantly larger measured negative axial offset deviation than predicted by core design calculations. The neutron flux depression in the upper half of high-power rods experiencing significant subcooled boiling is believed to be caused by the concentration of boron species within the crud layer formed on the cladding surface. Recent investigations of the root-cause mechanism for AOA [1,2] suggest that boron build-up on the fuel is caused by precipitation of lithium metaborate (LiBO2) within the crud in regions of subcooled boiling. Indirect evidence in support of this hypothesis was inferred from operating experience at Callaway, where lithium return and hide-out were, respectively, observed following power reductions and power increases when AOA was present. However, direct evidence of lithium metaborate precipitation within the crud has, heretofore, not been shown because of its retrograde solubility. To this end, this investigation has been undertaken in order to directly verify or refute the proposed root-cause mechanism of AOA, and examine the effectiveness of possible mitigating actions to limit its impact in high power PWR cores.
Date: July 2, 2005
Creator: Abdel-Khalik, Said
System: The UNT Digital Library
Electricity: The Road Toward Restructuring (open access)

Electricity: The Road Toward Restructuring

The Public Utility Holding Company Act of 1935 (PUHCA) and the Federal Power Act (FPA) were enacted to eliminate unfair practices and other abuses by electricity and gas holding companies by requiring federal control and regulation of interstate public utility holding companies. Comprehensive energy legislation has passed the House and Senate. The House passed H.R. 6 on April 11, 2003. On July 31, 2003, the Senate suspended debate on S. 14, inserted the text of H.R. 4 (107th Congress) as a substitute, and passed H.R. 6. A conference agreement was reached November 17, 2003, and passed by the House the next day. H.R. 6 includes an electricity title that would, in part, repeal PUHCA, would prospectively repeal the mandatory purchase requirement under PURPA, and would create an electric reliability organization. On June 15, 2004, H.R. 4503, a comprehensive energy policy bill, passed the House.
Date: May 2, 2003
Creator: Abel, Amy & Parker, Larry
System: The UNT Digital Library
Diffusion Simulation and Lifetime Calculation at RHIC (open access)

Diffusion Simulation and Lifetime Calculation at RHIC

The beam lifetime is an important parameter for any storage ring. For protons in RHIC it is dominated by the non-linear nature of the head-on collisions that causes the particles to diffuse outside the stable area in phase space. In this report we show results from diffusion simulation and lifetime calculation for the 2006 and 2008 polarized proton runs in RHIC.
Date: January 2, 2009
Creator: Abreu,N.P.; Fischer, W.; Luo, Y. & Robert-Demolaize, G.
System: The UNT Digital Library
Partial Closure Report for the Area 514 Treatment and Storage Facility (open access)

Partial Closure Report for the Area 514 Treatment and Storage Facility

The purpose of this partial closure report is to inform the Department of Toxic Substances Control (DTSC) of the status of final closure of the Area 514 Treatment and Storage Facility (Area 514) and fulfill the DTSC requirements to proceed with the implementation of the interim action. Area 514 is located at the Livermore main site of Lawrence Livermore National Laboratory (LLNL). LLNL is owned by the U.S. Department of Energy (DOE) and operated jointly by DOE and the University of California. LLNL received its permit to operate hazardous waste facilities from DTSC in 1997. The hazardous waste treatment and storage operations of Area 514 were transferred to a newly constructed complex, the Decontamination and Waste Treatment Facility (DWTF), in 2003. Once the DWTF was operational, the final closure of Area 514 began in accordance with the DTSC-approved closure plan in June 2004. Abri Environmental Engineering, Inc., was retained by LLNL to observe the A514 closure process and prepare this partial closure report and certification. Prior to closure, the configuration of the Area 514 Treatment and Storage Facility consisted of Building 514, the Area 514-1 Container Storage and Treatment unit, the Area 514-2 Container Storage Unit (CSU), the Area 514-3 …
Date: May 2, 2005
Creator: Abri, M
System: The UNT Digital Library
NATO Enlargement: Senate Advice and Consent (open access)

NATO Enlargement: Senate Advice and Consent

None
Date: May 2, 2003
Creator: Ackerman, David M.
System: The UNT Digital Library
Electroweak physics: measurement of w gamma and z gamma production in pp-bar collisions at s**(1/2) = 1.96 tev (open access)

Electroweak physics: measurement of w gamma and z gamma production in pp-bar collisions at s**(1/2) = 1.96 tev

The Standard Model predictions for W{gamma} and Z{gamma} production are tested using an integrated luminosity of 200 pb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E{sub T} > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W{gamma} and Z{gamma} data are compared to SM predictions.
Date: February 2, 2005
Creator: Acosta, D.
System: The UNT Digital Library
Exotic physics: search for long-lived doubly-charged higgs bosons in p anti-p collisions at s**(1/2) = 1.96 tev (open access)

Exotic physics: search for long-lived doubly-charged higgs bosons in p anti-p collisions at s**(1/2) = 1.96 tev

We present a search for long-lived doubly-charged Higgs bosons (H{sup {+-}{+-}}), with signatures of high ionization energy loss and muon-like penetration. We use 292 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly-charged particle production, we exclude H{sub L}{sup {+-}{+-}} and H{sub R}{sup {+-}{+-}} bosons with masses below 133 GeV/c{sup 2} and 109 GeV/c{sup 2}, respectively. In the degenerate case we exclude H{sup {+-}{+-}} mass below 146 GeV/c{sup 2}. All limits are quoted at the 95% confidence level.
Date: March 2, 2005
Creator: Acosta, D.
System: The UNT Digital Library
Applying Agile Methods to Weapon/Weapon-Related Software (open access)

Applying Agile Methods to Weapon/Weapon-Related Software

This white paper provides information and guidance to the Department of Energy (DOE) sites on Agile software development methods and the impact of their application on weapon/weapon-related software development. The purpose of this white paper is to provide an overview of Agile methods, examine the accepted interpretations/uses/practices of these methodologies, and discuss the applicability of Agile methods with respect to Nuclear Weapons Complex (NWC) Technical Business Practices (TBPs). It also provides recommendations on the application of Agile methods to the development of weapon/weapon-related software.
Date: May 2, 2007
Creator: Adams, Dennis; Armendariz, Maria; Blackledge, Mike; Campbell, Frank; Cloninger, Mack; Cox, Larry et al.
System: The UNT Digital Library
FY2001 Tank Characterization Technical Sampling Basis & Waste Information Requirements Document (open access)

FY2001 Tank Characterization Technical Sampling Basis & Waste Information Requirements Document

The Fiscal Year 2001 Tank Characterization Technical Sampling Basis and Waste Information Requirements Document (TSB-WIRD) has the following purposes: (1) To identify and integrate sampling and analysis needs for fiscal year (FY) 2001 and beyond. (2) To describe the overall drivers that require characterization information and to document their source. (3) To describe the process for identifying, prioritizing, and weighting issues that require characterization information to resolve. (4) To define the method for determining sampling priorities and to present the sampling priorities on a tank-by-tank basis. (5) To define how the characterization program is going to satisfy the drivers, close issues, and report progress. (6)To describe deliverables and acceptance criteria for characterization deliverables.
Date: August 2, 2000
Creator: Adams, M. R.
System: The UNT Digital Library
Lebanon: Background and U.S. Relations (open access)

Lebanon: Background and U.S. Relations

This report provides an overview of Lebanese politics, recent events in Lebanon, and current issues in U.S.-Lebanon relations and will be updated to reflect major developments.
Date: November 2, 2009
Creator: Addis, Casey L.
System: The UNT Digital Library
Application of a Device for Uniform Web Drying and Preheating Using Microwave Energy (open access)

Application of a Device for Uniform Web Drying and Preheating Using Microwave Energy

The project summarized in this report dealt with an evaluation of new microwave applicator ideas for paper preheating and drying. The technical basis for success in this project is the fact that Industrial Microwave Systems has recently identified certain previously unrecognized wave guide ''design variables'' and hardware implementation concepts that can be employed to greatly improve the uniformity of microwave energy distribution for continuous flow processes. Two applicator concepts were ultimately evaluated, a Cross-Machine Direction (CD) oriented applicator and a Machine Direction (MD) oriented applicator. The economic basis for success is the result of several factors. Since 1985, the capital expenditure required for an industrial microwave applicator system has decreased by a factor of four. The maintenance costs have decreased by a factor of 10 and the life expectancy of the magnetron has increased by more than a factor of four to in excess of 8,000 hours (nearly one year at 24 hours/day operation).
Date: October 2, 2003
Creator: Ahrens, Frederick W.; Habeger, C.; Loughran, J. & Patterson, T.
System: The UNT Digital Library
Laboratory Directed Research and Development FY2002 Annual Report (open access)

Laboratory Directed Research and Development FY2002 Annual Report

None
Date: May 2, 2003
Creator: Al-Ayat, R
System: The UNT Digital Library
Beyond the dna: a prototype for functional genomics (open access)

Beyond the dna: a prototype for functional genomics

A prototype oligonucleotide ''functional chip'' has been developed to screen novel DNA repair proteins for their ability to bind or alter different forms of DNA. This chip has been developed as a functional genomics screen for analysis of protein-DNA interactions for novel proteins identified from the Human Genome Project The process of novel gene identification that has ensued as a consequence of available sequence information is remarkable. The challenge how lies in determining the function of newly identified gene products in a time-and cost-effective high-throughput manner. The functional chip is generated by the robotic application of DNA spotted in a microarray format onto a glass slide. Individual proteins are then analyzed against the different form of DNA bound to the slide. Several prototype functional chips were designed to contain various DNA fragments tethered to a glass slide for analysis of protein-DNA binding or enzymatic activity of known proteins. The technology has been developed to screen novel, putative DNA repair proteins for their ability to bind various types of DNA alone and in concert with protein partners. An additional scheme has been devised to screen putative repair enzymes for their ability to process different types of DNA molecules. Current methods to …
Date: March 2, 2000
Creator: Albala, J
System: The UNT Digital Library
Does the Endangered Species Act (ESA) Listing Provide More Protection of the Polar Bear? (open access)

Does the Endangered Species Act (ESA) Listing Provide More Protection of the Polar Bear?

This report discusses the polar bear that has been protected under the Marine Mammal Protection Act (MMPA) since 1972. The polar bear was listed because the bear's primary habitat of sea ice was threatened with destruction due to global climate change.
Date: September 2, 2008
Creator: Alexander, Kristina
System: The UNT Digital Library
METAL FILTERS FOR PRESSURIZED FLUID BED COMBUSTION (PFBC) APPLICATIONS (open access)

METAL FILTERS FOR PRESSURIZED FLUID BED COMBUSTION (PFBC) APPLICATIONS

Advanced coal and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, and Hipps) are currently under development and demonstration. Efforts at the Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and demonstration of hot gas filter systems as an enabling technology for power generation. As part of the demonstration effort, SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field-tested filter elements, and has undertaken extended, accelerated filter life testing programs. This report reviews SWPC's material and component assessment efforts, identifying the performance, stability, and life of porous commercial metal, advanced alloy, and intermetallic filters under simulated, pressurized fluidized-bed combustion (PFBC) conditions.
Date: January 2, 2004
Creator: Alvin, M. A.
System: The UNT Digital Library
Guide to Individuals Seated on the House Dais (open access)

Guide to Individuals Seated on the House Dais

This report provides information about the Guide to Individuals Seated on the House Dais. The house of representatives meets in the capitol in the house chamber.
Date: October 2, 2007
Creator: Amer, Mildred
System: The UNT Digital Library
House Ethics Rules Changes in the 108th Congress (open access)

House Ethics Rules Changes in the 108th Congress

None
Date: April 2, 2004
Creator: Amer, Mildred
System: The UNT Digital Library
Colleges and Universities Attended by Representatives of the 107th Congress (open access)

Colleges and Universities Attended by Representatives of the 107th Congress

This report identifies the colleges and universities attended by representatives and delegates in the 107th Congress grouped by state.
Date: January 2, 2002
Creator: Amer, Mildred L.
System: The UNT Digital Library
Colleges and Universities Attended by Senators of the 107th Congress (open access)

Colleges and Universities Attended by Senators of the 107th Congress

This report identifies the colleges and universities attended by Senators serving in the 107th Congress. Where available in published sources, the degrees earned are also listed.
Date: January 2, 2002
Creator: Amer, Mildred L.
System: The UNT Digital Library
Supercritical Water Nuclear Steam Supply System: Innovations In Materials, Neutronics & Thermal-Hydraulics (open access)

Supercritical Water Nuclear Steam Supply System: Innovations In Materials, Neutronics & Thermal-Hydraulics

In the 1990's supercritical light-water reactors were considered in conceptual designs. A nuclear reactor cooled by supercritical waster would have a much higher thermal efficiency with a once-through direct power cycle, and could be based on standardized water reactor components (light water or heavy water). The theoretical efficiency could be improved by more than 33% over that of other water reactors and could be simplified with higher reliability; e.g., a boiling water reactor without steam separators or dryers.
Date: September 2, 2004
Creator: Anderson, Mark; Corradini, M.L.; Sridharan, K.; WIlson, P.; Cho, D.; Kim, T.K. et al.
System: The UNT Digital Library
Femtosecond, High-Brightness Electron Beam Generation and Advanced Diagnosis (open access)

Femtosecond, High-Brightness Electron Beam Generation and Advanced Diagnosis

This document serves as the final report for LDRD project number 04-LW-031, in which we created subpicosecond length, kilo-amp peak current electron beams with the 100 MeV electron/positron linac, using a novel technique designed to produce ultra-short bunch lengths while maintaining the high brightness produced by the S-band photoinjector. In addition, a diagnostic to measure the temporal distribution of the beam was investigated, as conventional pulse length measurement techniques do not apply to extremely short pulses. The creation and diagnosis of beams with both femtosecond length and high transverse brightness is of major concern to next generation acceleration and radiation production experiments. This work leveraged the previous investment in the PLEIADES facility and it's ability to produce high brightness electron beams. In addition, the ultra-short electron pulses generated by this work have been used in conjunction with the PLEIADES X-ray source to produce sub-picosecond, high-brightness X-ray pulses.
Date: February 2, 2005
Creator: Anderson, S G; Brown, W J; Tremaine, A M; Kuba, J; Hartemann, F V & Fittinghoff, D N
System: The UNT Digital Library