Final Scientific Report (open access)

Final Scientific Report

Viscosities of water, nitrogen and carbon dioxide have been measured at elevated pressures and temperatures in the diamond-anvil cell. A strong correlation between viscosity and entropy has been confirmed.
Date: June 26, 2009
Creator: Abramson, Evan
Object Type: Report
System: The UNT Digital Library
Insulated Pressure Vessels for Vehicular Hydrogen Storage: Analysis and Performance Evaluation (open access)

Insulated Pressure Vessels for Vehicular Hydrogen Storage: Analysis and Performance Evaluation

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (fuel flexibility, lower energy requirement for hydrogen liquefaction and reduced evaporative losses). The work described here is directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen. The use of commercially available pressure vessels significantly reduces the cost and complexity of the insulated pressure vessel development effort. This paper describes a series of tests that have been done with aluminum-lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. All analysis and experiments to date indicate that no significant damage has resulted. Required future tests are described that will prove that no technical barriers exist to the safe use of aluminum-fiber vessels at cryogenic temperatures. Future activities also include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for obtaining certification for insulated pressure vessels.
Date: June 26, 2001
Creator: Aceves, S. M.; Martinez-Frias, J.; Garcia-Villazana, O. & Espinosa-Loza, F.
Object Type: Article
System: The UNT Digital Library
GUT implications from neutrino mass (open access)

GUT implications from neutrino mass

An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO (10) SUSY GUT model formulated by S.M. Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super beam and a neutrino factory for determining the small U{sub e3} mixing matrix element.
Date: June 26, 2001
Creator: Albright, Carl H.
Object Type: Article
System: The UNT Digital Library
Final Technical Report for DE-FG02-97ER41038 Partial-wave Analyses of Scattering Reactions below 3 GeV, May 31, 1997 - May 31, 1999 (open access)

Final Technical Report for DE-FG02-97ER41038 Partial-wave Analyses of Scattering Reactions below 3 GeV, May 31, 1997 - May 31, 1999

None
Date: June 26, 2000
Creator: Arndt, Richard A. & Workman, R.L.
Object Type: Report
System: The UNT Digital Library
A Search for B+ to tau+ nu (open access)

A Search for B+ to tau+ nu

The authors present a search for the decay B{sup +} {yields} {tau}{sup +}{nu} using 383 x 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed semileptonic B decay (B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}{sub {ell}}X) is selected, and in the recoil a search for B{sup +} {yields} {tau}{sup +}{nu} is performed. The {tau} is identified in the following channels: {tau}{sup +} {yields} e{sup +}{nu}{bar {nu}}, {tau}{sup +} {yields} {mu}{sup +}{nu}{bar {nu}}, {tau}{sup +} {yields} {pi}{sup +} {bar {nu}} and {tau}{sup +} {yields} {pi}{sup +}{pi}{sup 0}{bar {nu}}. They measure a branching fraction of {Beta}(B{sup +} {yields} {tau}{sup +}{nu}) = (0.9 {+-} 0.6(stat.) {+-} 0.1(syst.)) x 10{sup -4}. In the absence of a significant signal, we calculate an upper limit at the 90% confidence level of {Beta}(B{sup +} {yields} {tau}{sup +}{nu}) < 1.7 x 10{sup -4}. They calculate the product of the B meson decay constant f{sub B} and |V{sub ub}| to be f{sub B} {center_dot} |V{sub ub}| = (7.2{sub -2.8}{sup +2.0}(stat.) {+-} 0.2(syst.)) x 10{sup -4} GeV.
Date: June 26, 2007
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Observation of e^+e^- to \rho^+\rho^- near \sqrt{s}=10.58\gev (open access)

Observation of e^+e^- to \rho^+\rho^- near \sqrt{s}=10.58\gev

The authors report the first observation of e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}, in a data sample of 379 fb{sup -1} collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at center-of-mass energies near {radical}s = 10.58 GeV. The authors measure a cross section of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}) = 19.5 {+-} 1.6(stat) {+-} 3.2(syst) fb. Assuming production through single-photon annihilation, there are three independent helicity amplitudes. They measure the ratios of their squared moduli to be |F{sub 00}|{sup 2} : |F{sub 10}|{sup 2} : |F{sub 11}|{sup 2} = 0.51 {+-} 0.14(stat) {+-} 0.07(syst) : 0.10 {+-} 0.04(stat) {+-} 0.01(syst) : 0.04 {+-} 0.03(stat) {+-} 0.01(syst). The |F{sub 00}|{sup 2} result is inconsistent with the prediction of 1.0 made by QCD models with a significance of 3.1 standard deviations including systematic uncertainties.
Date: June 26, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type: Article
System: The UNT Digital Library
END FIELD EFFECTS IN BEND ONLY COOLING LATTICES. (open access)

END FIELD EFFECTS IN BEND ONLY COOLING LATTICES.

Cooling lattices consisting only of bends (using either rotated pole faces or gradient dipoles to achieve focusing) often require large apertures and short magnets. One expects the effect of end fields to be significant in this case. In this paper we explore the effect of adding end fields to a working lattice design that originally lacked them. The paper describes the process of correcting the lattice design for the added end fields so as to maintain desirable lattice characteristics. It then compares the properties of the lattice with end fields relative to the lattice without them.
Date: June 26, 2003
Creator: BEERG,J. S. KIRK,H. GARREN,A.
Object Type: Article
System: The UNT Digital Library
DESIGN OF FFAGS BASED ON A FODO LATTICE. (open access)

DESIGN OF FFAGS BASED ON A FODO LATTICE.

An FFAG is a lattice with fixed magnetic fields that has an extremely wide energy acceptance. One particularly simple type of FFAG is based on a FODO lattice, where both quads can be combined-function bending/quadrupole magnets. The spaces between the combined-function magnets are left open for RF cavities and other hardware. This paper describes a general method for creating lattice designs for this type of lattice which gives the lattice optimal properties for an FFAG accelerator. The properties of this lattice as a function of input parameters are explored. The use of sextupoles to improve lattice properties is also explored.
Date: June 26, 2003
Creator: BERG,J. S. JOHNSTONE,C.
Object Type: Article
System: The UNT Digital Library
FFAGS FOR MUON ACCELERATION. (open access)

FFAGS FOR MUON ACCELERATION.

Due to their finite lifetime, muons must be accelerated very rapidly. It is challenging to make the magnets ramp fast enough to accelerate in a synchrotron, and accelerating in a linac is very expensive. One can use a recirculating accelerator (like CEBAF), but one needs a different arc for each turn, and this limits the number of turns one can use to accelerate, and therefore requires significant amounts of RF to achieve the desired energy gain. An alternative method for muon acceleration is using a fixed field alternating gradient (FFAG) accelerator. Such an accelerator has a very large energy acceptance (a factor of two or three), allowing one to use the same arc with a magnetic field that is constant over time. Thus, one can in principle make as many turns as one can tolerate due to muon decay, therefore reducing the RF cost without increasing the arc cost. This paper reviews the current status of research into the design of FFAGs for muon acceleration. Several current designs are described and compared. General design considerations are also discussed.
Date: June 26, 2003
Creator: BERG,J. S. KAHN,S. PALMER,R. TRBOJEVIC,D. JOHNSTONE,C. KEIL,Y. OGITSU,T. OHMORI,C. SESSLER,A. KOSCIELNIAK,S.
Object Type: Article
System: The UNT Digital Library
LINEAR DESIGN OF COMBINED FUNCTION IONIZATION COOLING LATTICES. (open access)

LINEAR DESIGN OF COMBINED FUNCTION IONIZATION COOLING LATTICES.

Ionization cooling lattices simultaneously require small beta-functions at the absorber and large energy acceptances to be effective. Simultaneously achieving these goals as well as having a good dynamic aperture requires that the lattice be relatively compact. If one wishes to avoid solenoids, one choice for creating such a lattice is to use combined-function magnets. These magnets can simultaneously focus in both planes, allowing one to achieve a low beta in both planes with a minimum number of magnets. In this paper we explore the design of lattices which contain only combined-function bending magnets using a thin-lens approximation, showing how to optimally achieve the requirements for muon cooling.
Date: June 26, 2003
Creator: BERG,J. S. KIRK,H. GARREN,A.
Object Type: Article
System: The UNT Digital Library
Experimental computation with oscillatory integrals (open access)

Experimental computation with oscillatory integrals

A previous study by one of the present authors, together with D. Borwein and I. Leonard [8], studied the asymptotic behavior of the p-norm of the sinc function: sinc(x) = (sin x)/x and along the way looked at closed forms for integer values of p. In this study we address these integrals with the tools of experimental mathematics, namely by computing their numerical values to high precision, both as a challenge in itself, and also in an attempt to recognize the numerical values as closed-form constants. With this approach, we are able to reproduce several of the results of [8] and to find new results, both numeric and analytic, that go beyond the previous study.
Date: June 26, 2009
Creator: Bailey, David H. & Borwein, Jonathan M.
Object Type: Report
System: The UNT Digital Library
Experimental Mathematics and Mathematical Physics (open access)

Experimental Mathematics and Mathematical Physics

One of the most effective techniques of experimental mathematics is to compute mathematical entities such as integrals, series or limits to high precision, then attempt to recognize the resulting numerical values. Recently these techniques have been applied with great success to problems in mathematical physics. Notable among these applications are the identification of some key multi-dimensional integrals that arise in Ising theory, quantum field theory and in magnetic spin theory.
Date: June 26, 2009
Creator: Bailey, David H.; Borwein, Jonathan M.; Broadhurst, David & Zudilin, Wadim
Object Type: Report
System: The UNT Digital Library
Studies of Dynamic Properties of Shock Compressed Solids by In-Situ Transient X-Ray Diffraction (open access)

Studies of Dynamic Properties of Shock Compressed Solids by In-Situ Transient X-Ray Diffraction

In the transient diffraction NLYF proposal we set forward a program of work to investigate the response of crystals to shock compression in regions of strain rates previously unexplored, in a coordinated experimental, computational, and analytical program. Time resolved x-ray diffraction was used to directly determine the lattice parameters of crystals during shock loading previously on the Nova and Trident laser facilities. Under this proposal we extended this work to exploit the multi-beam direct drive capability of the Omega laser facility to allow more extensive diagnostic access for measuring the lattice parameters both parallel and perpendicular to the shock front. Under the NLUF Program in FY 99, we transitioned the dynamic diffraction experiments to the OMEGA facility. We developed a direct drive target configuration that uses a single beam to direct irradiate the surface of a thin crystal and 4 beams to irradiate a separate metal backlighter foil. Experiments were done with single crystal Si to demonstrate that the target design worked and that simultaneous measurements of compression both parallel and perpendicular to the shock propagation direction could be performed. We obtained simultaneous measurements of the (400) and (040) lattice planes during the period when a shock traveled through the …
Date: June 26, 2000
Creator: Baldis, H.; Kalantar, D. H.; Remington, B. A.; Weber, S. V.; Meyers, M. A.; Wark, J. S. et al.
Object Type: Report
System: The UNT Digital Library
Strategic Petroleum Reserve (open access)

Strategic Petroleum Reserve

None
Date: June 26, 2002
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Possibilities for Nuclear Photo-Science with Intense Lasers (open access)

Possibilities for Nuclear Photo-Science with Intense Lasers

The interaction of intense laser light with relativistic electrons can produce unique sources of high-energy x rays and gamma rays via Thomson scattering. ''Thomson-Radiated Extreme X-ray'' (T-REX) sources with peak photon brightness (photons per unit time per unit bandwidth per unit solid angle per unit area) that exceed that available from world's largest synchrotrons by more than 15 orders of magnitude are possible from optimally designed systems. Such sources offer the potential for development of ''nuclear photo-science'' applications in which the primary photon-atom interaction is with the nucleons and not the valence electrons. Applications include isotope-specific detection and imaging of materials, inverse density radiography, transmutation of nuclear waste and fundamental studies of nuclear structure. Because Thomson scattering cross sections are small, < 1 barn, the output from a T-REX source is optimized when the laser spot size and the electron spot size are minimized and when the electron and laser pulse durations are similar and short compared to the transit time through the focal region. The principle limitation to increased x-ray or gamma-ray brightness is ability to focus the electron beam. The effects of space charge on electron beam focus decrease approximately linearly with electron beam energy. For this reason, …
Date: June 26, 2006
Creator: Barty, C. J.; Hartemann, F. V.; McNabb, D. P.; Messerly, M.; Siders, C.; Anderson, S. et al.
Object Type: Article
System: The UNT Digital Library
Modeling the long - term degradation of a metallic waste form. (open access)

Modeling the long - term degradation of a metallic waste form.

The principal aim of this effort is to develop models of long-term metal waste form (MWF) degradation that are credible, mechanistically based, and empirically calibrated. Utilizing new experimental data and analyses, this paper outlines an updated approach and summarizes the progress made. The current modeling approach emphasizes the analysis of constituent release data from immersion tests. A significant amount of recently obtained immersion test data is described. Test solutions included both mild (well-water), and aggressive (high-chloride and strongly acidic) environments. In addition to predominant constituents Fe, Zr, Cr,, and Ni, MWF test samples included: U, Pu, Tc, and Np. Guided by analysis of new immersion test data, a mechanistic model has been developed that describes the time dependence of MWF corrosion leading to passivation. A common functional form relates MWF degradation from different passivating solution environments via scale factors for magnitude and passivation time. Passivation is identified as the most important factor governing long-term durability, along with the long-term stability of oxide barrier layers that cause passivation. Experimental data demonstrated passivation behavior in nominal well water, concentrated well water, an aggressive high-chloride solution, but not in a strong acid. Credible bounding estimates of long-term corrosion for nominal well water solution …
Date: June 26, 2002
Creator: Bauer, T. H.; Johnson, S. G. & Snyder, C. T.
Object Type: Article
System: The UNT Digital Library
Relative Contributions of Fossil and Contemporary Carbon sources to PM 2.5 Aerosols at Nine IMPROVE Network Sites (open access)

Relative Contributions of Fossil and Contemporary Carbon sources to PM 2.5 Aerosols at Nine IMPROVE Network Sites

Particulate matter aerosols contribute to haze diminishing vistas and scenery at National Parks and Wilderness Areas within the United States. To increase understanding of the sources of carbonaceous aerosols at these settings, the total carbon loading and {sup 14}C/C ratio of PM 2.5 aerosols at nine IMPROVE (Interagency Monitoring for Protection Of Visual Environments) network sites were measured. Aerosols were collected weekly in the summer and winter at one rural site, two urban sites, five sites located in National Parks and one site located in a Wildlife Preserve. The carbon measurements together with the absence of {sup 14}C in fossil carbon materials and the known {sup 14}C/C levels in contemporary carbon materials were used to derive contemporary and fossil carbon contents of the particulate matter. Contemporary and fossil carbon aerosol loadings varied across the sites and suggest different percentages of carbon source inputs. The urban sites had the highest fossil carbon loadings that comprised around 50% of the total carbon aerosol loading. The Wildlife Preserve and National Park sites together with the rural site had much lower fossil carbon loading components. At these sites, variations in the total carbon aerosol loading were dominated by non-fossil carbon sources. This suggests that …
Date: June 26, 2006
Creator: Bench, G; Fallon, S; Schichtel, B; Malm, W & McDade, C
Object Type: Article
System: The UNT Digital Library
The incorporation of GIS in radiological transportation accident consequence assessments. (open access)

The incorporation of GIS in radiological transportation accident consequence assessments.

Potential impacts of transportation accidents must be addressed in documents prepared under the National Environmental Protection Act (NEPA) as amended or in other environmental-related documents when the transportation of radioactive materials is considered. Estimating the potential human health consequences from the release and dispersion of radioactive materials following such an accident involves a number of interrelated computational models and a variety of input parameters. The RISKIND radiological transportation risk computer program [1] was developed to provide these types of estimates for local scenarios. However, it is often difficult to gain a full understanding of the initial problem and consequences by looking solely at numerical input and tables of results. To permit better-informed decisions, visualization of the site-specific geographic area and the potential spread of contamination can provide greater understanding. Thus, a geographic information system (GIS) component has been integrated with RISKIND to provide visualization capabilities as well as site-specific and computational benefits.
Date: June 26, 2001
Creator: Biwer, B. M.; LePoire, D. J.; Kuiper, J. A. & Chen, S. Y.
Object Type: Article
System: The UNT Digital Library
Iraq: Oil and Gas Legislation, Revenue Sharing, and U.S. Policy (open access)

Iraq: Oil and Gas Legislation, Revenue Sharing, and U.S. Policy

This report reviews policy proposals and interim contracts, analyzes the positions of various Iraqi political actors, and discusses potential implications for U.S. foreign policy goals in Iraq.
Date: June 26, 2007
Creator: Blanchard, Christopher M.
Object Type: Report
System: The UNT Digital Library
Magnetic Fields above the Surface of aSuperconductor with Internal Magnetism (open access)

Magnetic Fields above the Surface of aSuperconductor with Internal Magnetism

The author presents a method for calculating the magnetic fields near a planar surface of a superconductor with a given intrinsic magnetization in the London limit. He computes solutions for various magnetic domain boundary configurations and derives relations between the spectral densities of the magnetization and the resulting field in the vacuum half space, which are useful if the magnetization can be considered as a statistical quantity and its features are too small to be resolved individually. The results are useful for analyzing and designing magnetic scanning experiments. Application to existing data from such experiments on Sr{sub 2}RuO{sub 4} show that a domain wall would have been detectable, but the magnetic field of randomly oriented small domains and small defects may have been smaller than the experimental noise level.
Date: June 26, 2007
Creator: Bluhm, Hendrik & /Stanford U., Phys. Dept. /SLAC, SSRl
Object Type: Article
System: The UNT Digital Library
Degradation of multibunch luminosity in a linear collider due to cumulative beam breakup (open access)

Degradation of multibunch luminosity in a linear collider due to cumulative beam breakup

Beam-excited transverse wakes in accelerating radiofrequency structures will influence the transverse offsets of each bunch in a multibunch train, causing the projected emittance of the bunch train to grow. An analytic theory of this phenomenon that includes the mitigating influence of a correlated energy spread across the bunch train was recently devised and applied to electron-positron linear colliders. We use the results of this theory to estimate analytically the associated degradation of multibunch luminosity in terms of top-level parameters for the two beams, the two accelerators, and the final-focus system. Then we compare the estimates with results from GUINEA-PIG, a code that includes the detailed physics of beam-beam interactions.
Date: June 26, 2001
Creator: Bohn, Courtlandt L.; Syphers, Michael J. & Schulte, Daniel
Object Type: Article
System: The UNT Digital Library
Stability of the Caustic-Side Solvent Extraction (CSSX) Process Solvent: Effect of High Nitrite on Solvent Nitration (open access)

Stability of the Caustic-Side Solvent Extraction (CSSX) Process Solvent: Effect of High Nitrite on Solvent Nitration

The purpose of this investigation was to determine whether nitrated organic compounds could be formed during operation of the Caustic-Side Solvent Extraction (CSSX) process, and whether such compounds would present a safety concern. The CSSX process was developed to remove cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site (SRS). The solvent is composed of the cesium extractant calix[4]arene-bis-(4-tert-octylbenzo-crown-6) (BOBCalixC6), a fluorinated alcohol phase modifier, tri-n-octylamine (TOA), and an isoparaffinic diluent (Iospar{reg_sign}). During the CSSX process, the solvent is expected to be exposed to high concentrations of nitrate and nitrite dissolved in the alkaline waste feed. The solvent will also be exposed to dilute (50 mM) nitric acid solutions containing low concentrations of nitrite during scrubbing, followed by stripping with 1 mM nitric acid. The solvent is expected to last for one year of plant operation, and the temperatures the solvent may experience during the process could range from as low as 15 C to as high as 35 C. Excursions from standard process conditions could result in the solvent experiencing higher temperatures, as well as concentrations of nitrate, nitrite, and most importantly nitric acid, that exceed normal operating conditions. Accordingly, conditions may …
Date: June 26, 2002
Creator: Bonnesen, P.V.
Object Type: Report
System: The UNT Digital Library
Recent Results from EBIT-II Using a Spare Astro-E Microcalorimeter (open access)

Recent Results from EBIT-II Using a Spare Astro-E Microcalorimeter

A spare NASA/GSFC Astro-E microcalorimeter has been installed, tested, and run successfully on EBIT-II at the Lawrence Livermore National Laboratory. A brief overview of results including measurements by the microcalorimeter of absolute excitation cross sections, time dependent spectra, and spectra as a function of Maxwellian temperature are discussed.
Date: June 26, 2001
Creator: Brown, G V; Behar, E; Beiersdorfer, P; Boyce, K R; Chen, H; Gendreau, K C et al.
Object Type: Article
System: The UNT Digital Library
Fishery, Aquaculture, and Marine Mammal Issues in the 111th Congress (open access)

Fishery, Aquaculture, and Marine Mammal Issues in the 111th Congress

This report gives an overview of Fishery, Aquaculture, and Marine Mammal Issues in the 111th Congress
Date: June 26, 2009
Creator: Buck, Eugene H.
Object Type: Report
System: The UNT Digital Library