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
Object Type: Report
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
Object Type: Report
System: The UNT Digital Library
THE FUTURE OF SPIN PHYSICS AT BNL. (open access)

THE FUTURE OF SPIN PHYSICS AT BNL.

The Relativistic Heavy Ion Collider (RHIC) at BNL is the world's only polarized proton-proton collider. Collisions at center-of-mass energies up to 500 GeV and beam polarizations approaching 70% (longitudinal or transverse) are provided to two experiments, STAR and PHENIX, at luminosities {ge} 10{sup 32}/cm{sup 2}/sec. Transverse polarized beam has also been provided to the BRAHMS experiment. Measurements that bear on the important question of the spin content of the nucleon are beginning to appear. Over the next 10 years, as the performance of polarized proton running at RHIC is further developed, the Spin Physics program at RHIC will provide definitive measurements of the contributions to the proton's spin of the gluon, the sea quarks and the orbital motion of the partons in the proton's wave function. We plan to extend the reach of our study of the role of spin in QCD with the development of ''eRHIC'', which will provide polarized e-p collisions to a new detector.
Date: October 2, 2006
Creator: ARONSON, S. & DESHPANDE, A.
Object Type: Article
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.
Object Type: Report
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
Object Type: Report
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
Object Type: Report
System: The UNT Digital Library
Global polarization measurement in Au+Au collisions (open access)

Global polarization measurement in Au+Au collisions

The system created in non-central relativisticnucleus-nucleus collisions possesses large orbital angular momentum. Dueto spin-orbit coupling, particles produced in such a system could becomeglobally polarized along the direction of the system angular momentum. Wepresent the results of Lambda and anti-Lambda hyperon global polarizationmeasurements in Au+Au collisions at sqrt sNN=62.4 GeV and 200 GeVperformed with the STAR detector at RHIC. The observed globalpolarization of Lambda and anti-Lambda hyperons in the STAR acceptance isconsistent with zero within the precision of the measurements. Theobtained upper limit, lbar P Lambda, anti-Lambda rbar<= 0.02, iscompared to the theoretical values discussed recently in theliterature.
Date: August 2, 2007
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of Transverse Single-Spin Asymmetries for Di-JetProduction in Proton-Proton Collisions at sqrt s = 200 GeV (open access)

Measurement of Transverse Single-Spin Asymmetries for Di-JetProduction in Proton-Proton Collisions at sqrt s = 200 GeV

We report the first measurement of the opening angledistribution between pairs of jets produced in high-energy collisions oftransversely polarized protons. The measurement probes (Sivers)correlations between the transverse spin orientation of a proton and thetransverse momentum directions of its partons. With both beams polarized,the wide pseudorapidity (-1 leq eta leq +2) coverage for jets permitsseparation of Sivers functions for the valence and sea regions. Theresulting asymmetries are all consistent with zero and considerablysmaller than Sivers effects observed in semi-inclusive deep inelasticscattering (SIDIS). We discuss theoretical attempts to reconcile the newresults with the sizable transverse spin effects seen in SIDIS andforward hadron production in pp collisions.
Date: October 2, 2007
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type: Article
System: The UNT Digital Library
New Correction Procedure for X-Ray Spectroscopic Fluorescence Data: Simulations and Experiment. (open access)

New Correction Procedure for X-Ray Spectroscopic Fluorescence Data: Simulations and Experiment.

X-ray fluorescence spectroscopy is a widely used method for determining the electronic configuration and local structure of dilute species with high sensitivity. In the dilute limit, and for thin films, the X-ray fluorescence signal is directly proportional to the atomic sub-shell absorption coefficient. However, for concentrated samples, the well-documented self-absorption effect often leads to the severe suppression of XANES (X-ray Absorption Near-Edge Structure) and EXAFS (Extended X-ray Absorption Fine-Structure) amplitudes. Thus to recover the real value of the sub-shell absorption coefficient, it is important to apply correction procedures to the measured fluorescence spectra. In this paper, we describe a new straightforward method to correct for self-absorption effects (the difference in the measured fluorescence signal compared to that of the true sub-shell photoabsorption coefficient) in XANES and EXAFS fluorescence measurements. Using a variety of sample and detector configurations, this method is used to extract the sub-shell absorption coefficient on elemental nickel and thick single-crystals of Gd{sub 3}Ga{sub 5}O{sub 12} and LaAlO{sub 3}.
Date: August 2, 2004
Creator: Ablett, J. M.; Woicik, J. C. & Kao, C. C.
Object Type: Article
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.
Object Type: Report
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
Object Type: Report
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.
Object Type: Report
System: The UNT Digital Library
Cation distribution in a Fe-bearing K-feldspar from Itrongay,Madagascar. A combined neutron- and X-ray single crystal diffractionstudy (open access)

Cation distribution in a Fe-bearing K-feldspar from Itrongay,Madagascar. A combined neutron- and X-ray single crystal diffractionstudy

We determined the cation distribution and ordering of Si, Al and Fe on the tetrahedral sites of a monoclinic low-sanidine from Itrongay, Madagascar, by combined neutron- and X-ray single-crystal diffraction. The cation distribution was determined by means of a simultaneous refinement using neutron- and X-ray data, as well as by combining scattering densities obtained from separate refinements with chemical data from a microprobe experiment. The two methods give the same results and show that Fe is fully ordered on T1, whereas Al shows a high degree of disorder. Based on this and previously published temperature-dependent X-ray data, we conclude that it is preferential ordering of Fe on T1 even at high temperature, rather than a high diffusion kinetics of Fe, which causes this asymmetry in ordering behavior between Al and Fe. The preferential ordering of Fe3+ relative to Al3+ in T1 is consistent with its 25 percent larger ionic radius.
Date: May 2, 2005
Creator: Ackermann, Sonia; Kunz, Martin; Armbruster, Thomas; Schefer,Jurg & Hanni, Henry
Object Type: Article
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} &gt; 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.
Object Type: Report
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.
Object Type: Report
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.
Object Type: Report
System: The UNT Digital Library
Event-by-event hexb pt hexb fluctuations in Au-Au collisions atsqrt(sNN) = 130 GeV (open access)

Event-by-event hexb pt hexb fluctuations in Au-Au collisions atsqrt(sNN) = 130 GeV

We present the first large-acceptance measurement of event-wise &lt;p{sub t}&gt; fluctuations in Au-Au collisions at {radical}s{sub NN} = 130 GeV. Significant nonstatistical fluctuations are observed. The measured fractional r.m.s. width excess of the event-wise &lt;p{sub t}&gt; distribution for the 15% most-central events for charged hadrons within |{eta}| &lt; 1 and 0.15 {le} p{sub t} {le} 2 GeV/c is 13.7 {+-} 0.1(stat) {+-}1.3(syst)% relative to a statistical reference. The variation of charge-independent fluctuation excess with centrality is non-monotonic but smooth. Charge-dependent nonstatistical fluctuations are also observed.
Date: September 2, 2003
Creator: Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type: Article
System: The UNT Digital Library
Transverse-Momentum and Collision Energy Dependence of High p{sub T} Hadron Suppression in Au+Au Collisions at Ultrarelativistic Energies (open access)

Transverse-Momentum and Collision Energy Dependence of High p{sub T} Hadron Suppression in Au+Au Collisions at Ultrarelativistic Energies

No abstract prepared.
Date: September 2, 2003
Creator: Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type: Article
System: The UNT Digital Library
Measurements of Transverse Energy Distributions in Au+Au Collisions at {radical}s{sub NN} = 200 GeV (open access)

Measurements of Transverse Energy Distributions in Au+Au Collisions at {radical}s{sub NN} = 200 GeV

Transverse energy (E{sub T}) distributions have been measured for Au+Au collisions at {radical}s{sub NN} = 200 GeV by the STAR collaboration at RHIC. E{sub T} is constructed from its hadronic and electromagnetic components, which have been measured separately. E{sub T} production for the most central collisions is well described by several theoretical models whose common feature is large energy density achieved early in the fireball evolution. The magnitude and centrality dependence of E{sub T} per charged particle agrees well with measurements at lower collision energy, indicating that the growth in E{sub T} for larger collision energy results from the growth in particle production. The electromagnetic fraction of the total E{sub T} is consistent with a final state dominated by mesons and independent of centrality.
Date: July 2, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
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.
Object Type: Report
System: The UNT Digital Library
MOBILE SYSTEMS FOR DILUTION OF HIGHLY ENRICHED URANIUM AND URANIUM CONTAINING COMPONENTS (open access)

MOBILE SYSTEMS FOR DILUTION OF HIGHLY ENRICHED URANIUM AND URANIUM CONTAINING COMPONENTS

A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed. The process utilizes a closed system approach to retain fission products/gases inside a sealed canister after treatment. The MMD process melts and dilutes spent fuel with depleted uranium to obtain a fissile fraction of less than 0.2. The final ingot is solidified inside the sealed canister and can be stored safely either wet or dry until final disposition or reprocessing. The MMD module can be staged at or near the research reactor fuel storage sites to facilitate the melt-dilute treatment of the spent fuel into a stable non-proliferable form.
Date: May 2, 2007
Creator: Adams, T
Object Type: Article
System: The UNT Digital Library
Characterization of Environmental Stability of Pulsed Laser Deposited Oxide Ceramic Coatings (open access)

Characterization of Environmental Stability of Pulsed Laser Deposited Oxide Ceramic Coatings

A systematic investigation of candidate hydrogen permeation materials applied to a substrate using Pulsed Laser Deposition has been performed. The investigation focused on application of leading permeation-resistant materials types (oxide, carbides, and metals) on a stainless steel substrate. and evaluation of the stability of the applied coatings. Type 304L stainless steel substrates were coated with aluminum oxide, chromium oxide, and aluminum. Characterization of the coating-substrate system adhesion was performed using scratch adhesion testing and microindentation. Coating stability and environmental susceptibility were evaluated for two conditions-air at 350 degrees Celsius and Ar-H2 at 350 degrees Celsius for up to 100 hours. Results from this study have shown the pulsed laser deposition process to be an extremely versatile technology that is capable of producing a sound coating/substrate system for a wide variety of coating materials.
Date: March 2, 2004
Creator: Adams, Thad M.
Object Type: Article
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.
Object Type: Report
System: The UNT Digital Library
MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10' to 5 Degrees (open access)

MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10' to 5 Degrees

We present a map and an angular power spectrum of the anisotropy of the cosmic microwave background (CMB) from the first flight of MAXIMA. MAXIMA is a balloon-borne experiment with an array of 16 bolometric photometers operated at 100 mK. MAXIMA observed a 124 deg region of the sky with 10' resolution at frequencies of 150, 240 and 410 GHz. The data were calibrated using in-flight measurements of the CMB dipole anisotropy. A map of the CMB anisotropy was produced from three 150 and one 240 GHz photometer without need for foreground subtractions. Analysis of this CMB map yields a power spectrum for the CMB anisotropy over the range 36 {le} {ell} {le} 785. The spectrum shows a peak with an amplitude of 78 {+-} 6 {mu}K at {ell} {approx_equal} 220 and an amplitude varying between {approx} 40 {mu}K and {approx} 50 {mu}K for 400 {approx}&lt; {ell} {approx}&lt; 785.
Date: October 2, 2000
Creator: Ade, P.; Balbi, A.; Bock, J.; Borrill, J.; Boscaleri, A.; deBernardis, P. et al.
Object Type: Article
System: The UNT Digital Library