A MOBILE MELT-DILUTE MODULE FOR THE TREATMENT OF ALUMINUM RESEARCH REACTOR SPENT FUEL (open access)

A MOBILE MELT-DILUTE MODULE FOR THE TREATMENT OF ALUMINUM RESEARCH REACTOR SPENT FUEL

A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed jointly by the Savannah River National Laboratory and Argonne National Laboratory. The process uses 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 an isotopic content of less than 20 percent. 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: November 3, 2004
Creator: ADAMS, THAD
System: The UNT Digital Library
The Nonlinear cosmological matter power spectrum with massive neutrinos. 1. The Halo model (open access)

The Nonlinear cosmological matter power spectrum with massive neutrinos. 1. The Halo model

Measurements of the linear power spectrum of galaxies have placed tight constraints on neutrino masses. We extend the framework of the halo model of cosmological nonlinear matter clustering to include the effect of massive neutrino infall into cold dark matter (CDM) halos. The magnitude of the effect of neutrino clustering for three degenerate mass neutrinos with m{sub v{sub 1}} = 0.9 eV is of order {approx}1%, within the potential sensitivity of upcoming weak lensing surveys. In order to use these measurements to further constrain--or eventually detect--neutrino masses, accurate theoretical predictions of the nonlinear power spectrum in the presence of massive neutrinos will be needed, likely only possible through high-resolution multiple particle (neutrino, CDM and baryon) simulations.
Date: November 1, 2004
Creator: Abazajian, Kevork; Alamos, /Los; Switzer, Eric R.; U., /Princeton; Dodelson, Scott; /Fermilab /Chicago U., Astron. Astrophys. Ctr. et al.
System: The UNT Digital Library
A Search for anomalous heavy-flavor quark production in association with W bosons (open access)

A Search for anomalous heavy-flavor quark production in association with W bosons

None
Date: November 1, 2004
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Co-localization of L-Phenylalanine Ammonia-Lyase and Cinnamate 4-Hydroxylase for Metabolic Channeling in Phenylpropanoid Biosynthesis (open access)

Co-localization of L-Phenylalanine Ammonia-Lyase and Cinnamate 4-Hydroxylase for Metabolic Channeling in Phenylpropanoid Biosynthesis

Article on the co-localization of L-phenylalanine ammonia-lyase and cinnamate 4-hydroxylase for metabolic channeling in phenylpropanoid biosynthesis.
Date: November 2004
Creator: Achnine, Lahoucine; Blancaflor, Elison B.; Rasmussen, Susanne & Dixon, R. A.
System: The UNT Digital Library
Measurement of the W boson polarization in top decay at CDF at s**(1/2) = 1.8-TeV (open access)

Measurement of the W boson polarization in top decay at CDF at s**(1/2) = 1.8-TeV

The polarization of the W boson in t {yields} Wb decay is unambiguously predicted by the Standard Model of electroweak interactions and is a powerful test of our understanding of the tbW vertex. We measure this polarization from the invariant mass of the b quark from t {yields} Wb and the lepton from W {yields} {ell}{nu} whose momenta measure the W decay angle and direction of motion, respectively. In this paper we present a measurement of the decay rate (f{sub V + A}) of the W produced from the decay of the top quark in the hypothesis of V + A structure of the tWb vertex. We find no evidence for the non-standard V + A vertex and set a limit on f{sub V + A} < 0.80 at 95% confidence level. By combining this result with a complementary observable in the same data, we assign a limit on f{sub V + A} < 0.61 at 95% CL. This corresponds to a constraint on the right-handed helicity component of the W polarization of f{sub +} < 0.18 at 95% CL. This limit is the first significant direct constraint on f{sub V + A} in top decay.
Date: November 1, 2004
Creator: Acosta, D.; Affolder, Anthony A.; Albrow, M. G.; Ambrose, D.; Amidei, D.; Anikeev, K. et al.
System: The UNT Digital Library
Pulse length dependence of laser conditioning and bulk damage in KD2PO4 (open access)

Pulse length dependence of laser conditioning and bulk damage in KD2PO4

An experimental technique has been developed to measure the damage density {rho}({phi}) variation with fluence from scatter maps of bulk damage sites in plates of KD{sub 2}PO{sub 4} (DKDP) crystals combined with calibrated images of the damaging beam's spatial profile. Unconditioned bulk damage in tripler-cut DKDP crystals has been studied using 351 nm (3 {omega}) light at pulse lengths of 0.055, 0.091, 0.30, 0.86, 2.6, and 10 ns. It is found that there is less scatter due to damage at fixed fluence for longer pulse lengths. The results also show that for all the pulse lengths the scatter due to damage is a strong function of the damaging fluence. It is determined that the pulse length scaling for bulk damage scatter in unconditioned DKDP material varies as {tau}{sup 0.24 {+-} 0.05} over two orders of magnitude of pulse lengths. The effectiveness of 3 {omega} laser conditioning at pulse lengths of 0.055, 0.096, 0.30, 0.86, 3.5, and 23 ns is analyzed in term of damage density {rho}({phi}) at 3 {omega}, 2.6 ns. The 860 ps conditioning to a peak irradiance of 7 GW/cm{sup 2} had the best performance under 3 {omega}, 2.6 ns testing. It is shown that the optimal conditioning …
Date: November 10, 2004
Creator: Adams, J. J.; Weiland, T. L.; Stanley, J. R.; Sell, W. D.; Luthi, R. L.; Vickers, J. L. et al.
System: The UNT Digital Library
Minijet Deformation and Charge-independent Two-particleCorrelations on Momentum Subspace (eta,phi) In Au-Au Collisions atsqrt(sNN) = 130 GeV (open access)

Minijet Deformation and Charge-independent Two-particleCorrelations on Momentum Subspace (eta,phi) In Au-Au Collisions atsqrt(sNN) = 130 GeV

We present first measurements of charge-independent correlations on momentum-space difference variables {eta}{sub 1}-{eta}{sub 2} (pseudorapidity) and {phi}{sub 1}-{phi}{sub 2} (azimuth) for charged primary hadrons with transverse momentum within 0.15 {le} p{sub t} {le} 2 GeV/c and |{eta}| {le} 1.3 from Au-Au collisions at {radical}s{sub NN} = 130 GeV. We observe strong charge-independent correlations associated with minijets and elliptic flow. The width of the minijet peak on {eta}{sub 1}-{eta}{sub 2} increases by a factor 2.3 from peripheral to central collisions, suggesting strong coupling of partons to a longitudinally-expanding colored medium. New methods of jet analysis introduced here reveal nonperturbative medium effects in heavy ion collisions.
Date: November 4, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
System: The UNT Digital Library
High-purity, isotopically enriched bulk silicon (open access)

High-purity, isotopically enriched bulk silicon

The synthesis and characterization of dislocation-free, undoped, single crystals of Si enriched in all 3 stable isotopes is reported: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (89.8%). A silane-based process compatible with the relatively small amounts of isotopically enriched precursors that are practically available was used. The silane is decomposed to silicon on a graphite starter rod heated to 700-750 C in a recirculating flow reactor. A typical run produces 35 gm of polycrystalline Si at a growth rates of 5 {micro}m/min and conversion efficiency >95%. Single crystals are grown by the floating zone method and characterized by electrical and optical measurements. Concentrations of shallow dopants (P and B) are as low as mid-10{sup 13} cm{sup -3}. Concentrations of C and O lie below 10{sup 16} and 10{sup 15} cm{sup -3}, respectively.
Date: November 17, 2004
Creator: Ager, J. W., III; Beeman, J. W.; Hansen, W. L.; Haller, E. E.; Sharp, I. D.; Liao, C. et al.
System: The UNT Digital Library
Mass of the B(c) meson in three-flavor lattice QCD (open access)

Mass of the B(c) meson in three-flavor lattice QCD

The authors use lattice QCD to predict the mass of the B{sub c} meson. They use the MILC Collaborations publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). The final result is m{sub B{sub c}} = 6304 {+-} 12{sub -0}{sup +18} MeV. The first error bar is a sum in quadrature of statistical and systematic uncertainties, and the second is an estimate of heavy-quark discretization effects.
Date: November 1, 2004
Creator: Allison, Ian F.; Davies, Christine T. H.; Gray, Alan; Kronfeld, Andreas S.; Mackenzie, Paul B. & Simone, James N.
System: The UNT Digital Library
Development of low coefficient of thermal expansion (CTE) nickel alloys for potential use as interconnects in SOFC (open access)

Development of low coefficient of thermal expansion (CTE) nickel alloys for potential use as interconnects in SOFC

This paper deals with the development of low coefficient of thermal expansion (CTE) nickel-base superalloys for potential use as interconnects for SOFC. Ni-Mo-Cr alloys were formulated with CTE on the order of 12.5 to 13.5 x10-6/°C. The alloys were vacuum induction melted and reduced to sheet via a combination of hot and cold working. Dilatometry was used to measure CTE of the alloys. Oxidation behavior of the alloys at 800°C in dry and moist air is reported. The results are compared to results for Haynes 230 (a commercial Ni-base superalloy) and for Crofer 22APU (a commercial ferritic stainless steel designed specifically for use as an SOFC interconnect).
Date: November 1, 2004
Creator: Alman, David E. & Jablonski, Paul D.
System: The UNT Digital Library
WxWindows Interface for CALE (open access)

WxWindows Interface for CALE

wxWindows is an Open Source, platform independent, User Interface (UI) which has been in development for over eleven years (http://www.wxwindows.org). Currently wxWindows is actively supported for the Linux/Unix (X11, Motif and GTK+), Mac OS 9 and X, all Win32 OSes, MGL, and OS/2 operating systems. wxWindows is written in C++ using an object oriented programming framework; it is a reasonably lightweight API (called wxWidgets) sitting over the native graphics packages of the various platforms it supports. The original version of CALE was written for the basic target platform of Unix using X11 as the graphics package. There have been separate efforts to port the code to Mac OS 9, Mac OS X, Win32, Windows Services for Unix (SFU) and CygWin. Each of these used a variety of different graphical interface approaches and build/make systems. For instance Windows SFU and CygWin could still only use X11 graphics. So could the Win32 version, if a X11 server library and client software were installed. A native Win32 version of CALE was contemplated, but never started. The Macintosh versions were completed but never widely distributed to the users. Given the growing code version support issues, and the slow deviation from the portable code model …
Date: November 24, 2004
Creator: Amala, P; Egner, C & Hagelberg, J
System: The UNT Digital Library
Critical current and instability threshold measurement of Nb3Sn cables for high field accelerator magnets (open access)

Critical current and instability threshold measurement of Nb3Sn cables for high field accelerator magnets

Rutherford-type cables made of high critical current Nb{sub 3}Sn strands are being used in several laboratories for developing new generation superconducting magnets for present and future accelerators and upgrades. Testing of cable short samples is an important part of these R&D programs and the instability problem found in some short model magnets at Fermilab made these tests even more significant. Fermilab in collaboration with BNL, CERN and LBNL has developed sample holders and sample preparation infrastructure and procedures for testing Nb{sub 3}Sn cable short samples at BNL and CERN test facilities. This paper describes the sample holders, sample preparation and instrumentation, and test results. Several samples made of MJR or PIT strands 1 mm in diameter have been tested. Some samples were unstable (i.e. quenched at low transport currents) at low fields and reached the critical surface at higher fields.
Date: November 1, 2004
Creator: Ambrosio, G.; Andreev, N.; /Fermilab; Bartlett, S. E.; /LBL, Berkeley; Barzi, E. et al.
System: The UNT Digital Library
A scaling law for the snapback in superconducting accelerator magnets (open access)

A scaling law for the snapback in superconducting accelerator magnets

The decay of the sextupole component in the bending dipoles during injection and the subsequent snapback at the start of beam acceleration are issues of common concern for all superconducting colliders built or in construction. Recent studies performed on LHC and Tevatron dipole magnets revealed many similarities in the snapback characteristics. Some are expected, e.g. the effect of operational history. One particular similarity, however, is striking and is the subject of this paper. It appears that there is a simple linear relation between the amount of sextupole drift during the decay and the magnet current (or field) change during the ramp required to resolve the snapback. It is surprising that the linear correlation between snapback amplitude and snapback field holds very well for all magnets of the same family (e.g. Tevatron or LHC dipoles). In this paper we present the data collected to date and discuss a simple theory that explains the scaling found.
Date: November 1, 2004
Creator: Ambrosio, G.; Bauer, P.; Bottura, L.; Haverkamp, M.; Pieloni, T.; Sanfilippo, S. et al.
System: The UNT Digital Library
Initial scientific uses of coherent synchrotron radiation inelectron storage rings (open access)

Initial scientific uses of coherent synchrotron radiation inelectron storage rings

The production of stable, high power, coherent synchrotron radiation at sub-terahertz frequency at the electron storage ring BESSY opens a new region in the electromagnetic spectrum to explore physical properties of materials. Just as conventional synchrotron radiation has been a boon to x-ray science, coherent synchrotron radiation may lead to many new innovations and discoveries in THz physics. With this new accelerator-based radiation source we have been able to extend traditional infrared measurements down into the experimentally poorly accessible sub-THz frequency range. The feasibility of using the coherent synchrotron radiation in scientific applications was demonstrated in a series of experiments: We investigated shallow single acceptor transitions in stressed and unstressed Ge:Ga by means of photoconductance measurements below 1 THz. We have directly measured the Josephson plasma resonance in optimally doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} for the first time and finally we succeeded to confine the sub-THz radiation for spectral near-field imaging on biological samples such as leaves and human teeth.
Date: November 23, 2004
Creator: Basov, D. N.; Feikes, J.; Fried, D.; Holldack, K.; Hubers, H. W.; Kuske, P. et al.
System: The UNT Digital Library
Probing electroweak top quark couplings at hadron colliders (open access)

Probing electroweak top quark couplings at hadron colliders

None
Date: November 1, 2004
Creator: Baur, U.; Juste, A.; Orr, L. H. & Rainwater, D.
System: The UNT Digital Library
B-decays in the heavy-quark expansion (open access)

B-decays in the heavy-quark expansion

Progress in the theoretical description of B-meson decays, in particular decays to light hadrons, is reviewed. The factorization properties of such decays can be analyzed using the soft-collinear effective theory. Applications of the effective theory to both inclusive and exclusive decays are discussed.
Date: November 1, 2004
Creator: Becher, Thomas
System: The UNT Digital Library
Search for rare leptonic B decays at the Tevatron (open access)

Search for rare leptonic B decays at the Tevatron

Results of a search for the Flavor-Changing Neutral Current decay B{sub s,d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} using p{bar p} collision data at {radical}s = 1.96 TeV collected at Fermilab Tevatron collider by the CDF and D0 detectors are presented. CDF reports upper limits on {Beta}(B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}) {le} 7.5 {center_dot} 10{sup -7} and {Beta}(B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -}) {le} 1.9 {center_dot} 10{sup -7} at the 95% C.L. using 171 pb{sup -1}. The D0 Collaboration used 240 pb{sup -1} to set an even more stringent limit on the branching ratio for B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -} of 5.0 {center_dot} 10{sup -7} at the 95% C.L..
Date: November 1, 2004
Creator: Bernhard, Ralf Patrick & U., /Zurich
System: The UNT Digital Library
Sulfur-induced corrosion of Au(111) studied by real-time STM (open access)

Sulfur-induced corrosion of Au(111) studied by real-time STM

The interaction of sulfur with gold surfaces has attracted considerable interest due to numerous technological applications such as the formation of self-assembled monolayers (SAMs), use as a corrosion inhibitor, and as a chemical sensor. In this work, the interaction of sulfur with Au(111) at two different temperatures (300 K and 420 K) was studied by real-time scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and Auger electron spectroscopy (AES). In the low coverage regime (< 0.1 monolayer), S modifies the surface stress leading to a lateral expansion of the Au surface layer. An ordered ({radical}3 x {radical}3)R30{sup o} sulfur adlayer develops as the coverage reaches {approx}0.3 ML. With further increasing S coverage the Au(111) surface undergoes a dynamic rearrangement while forming a two-dimensional AuS phase: gold surface atoms are removed from regular terrace sites and incorporated into the growing gold sulfide phase resulting in the appearance of pits and irregularly shaped AuS islands. Gold sulfide prepared at room temperature exhibits short-range order; an incommensurate, long-range ordered AuS phase develops upon annealing at 450-525 K. Higher temperatures lead to decomposition of the AuS corrosion film. Formation of an ordered AuS phase via rapid step retraction rather than etch pit formation …
Date: November 2, 2004
Creator: Biener, M. M.; Biener, J. & Friend, C. M.
System: The UNT Digital Library
2-MV electrostatic quadrupole injector for heavy-ion fusion (open access)

2-MV electrostatic quadrupole injector for heavy-ion fusion

High current and low emittance are principal requirements for heavy-ion injection into a linac driver for inertial fusion energy. An electrostatic quadrupole (ESQ) injector is capable of providing these high charge density and low emittance beams. We have modified the existing 2-MV Injector to reduce beam emittance and to double the pulse length. We characterize the beam delivered by the modified injector to the High Current Transport Experiment (HCX) and the effects of finite rise time of the extraction voltage pulse in the diode on the beam head. We demonstrate techniques for mitigating aberrations and reducing beam emittance growth in the injector.
Date: November 10, 2004
Creator: Bieniosek, F. M.; Celata, C. M.; Henestroza, E.; Kwan, J. W.; Prost, L. & Seidl, P. A.
System: The UNT Digital Library
Three-Dimensional Hydrodynamics Experiments on the National Ignition Facility (open access)

Three-Dimensional Hydrodynamics Experiments on the National Ignition Facility

The production of supersonic jets of material via the interaction of a strong shock wave with a spatially localized density perturbation is a common feature of inertial confinement fusion and astrophysics. The behavior of two-dimensional (2D) supersonic jets has previously been investigated in detail [J. M. Foster et. al, Phys. Plasmas 9, 2251 (2002)]. In three-dimensions (3D), however, there are new aspects to the behavior of supersonic jets in compressible media. In this paper, the commissioning activities on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)] to enable hydrodynamic experiments will be presented as well as the results from the first series of hydrodynamic experiments. In these experiments, two of the first four beams of NIF are used to drive a 40 Mbar shock wave into millimeter scale aluminum targets backed by 100 mg/cc carbon aerogel foam. The remaining beams are delayed in time and are used to provide a point-projection x-ray backlighter source for diagnosing the three-dimensional structure of the jet evolution resulting from a variety of 2D and 3D features. Comparisons between data and simulations using several codes will be presented.
Date: November 12, 2004
Creator: Blue, B. E.; Weber, S. V.; Glendinning, S.; Lanier, N.; Woods, D.; Bono, M. et al.
System: The UNT Digital Library
Beyond Linear Sequence Comparisons: The use of genome-levelcharacters for phylogenetic reconstruction (open access)

Beyond Linear Sequence Comparisons: The use of genome-levelcharacters for phylogenetic reconstruction

Although the phylogenetic relationships of many organisms have been convincingly resolved by the comparisons of nucleotide or amino acid sequences, others have remained equivocal despite great effort. Now that large-scale genome sequencing projects are sampling many lineages, it is becoming feasible to compare large data sets of genome-level features and to develop this as a tool for phylogenetic reconstruction that has advantages over conventional sequence comparisons. Although it is unlikely that these will address a large number of evolutionary branch points across the broad tree of life due to the infeasibility of such sampling, they have great potential for convincingly resolving many critical, contested relationships for which no other data seems promising. However, it is important that we recognize potential pitfalls, establish reasonable standards for acceptance, and employ rigorous methodology to guard against a return to earlier days of scenario-driven evolutionary reconstructions.
Date: November 27, 2004
Creator: Boore, Jeffrey L.
System: The UNT Digital Library
Advanced diffusion studies with isotopically controlled materials (open access)

Advanced diffusion studies with isotopically controlled materials

The use of enriched stable isotopes combined with modern epitaxial deposition and depth profiling techniques enables the preparation of material heterostructures, highly appropriate for self- and foreign-atom diffusion experiments. Over the past decade we have performed diffusion studies with isotopically enriched elemental and compound semiconductors. In the present paper we highlight our recent results and demonstrate that the use of isotopically enriched materials ushered in a new era in the study of diffusion in solids which yields greater insight into the properties of native defects and their roles in diffusion. Our approach of studying atomic diffusion is not limited to semiconductors and can be applied also to other material systems. Current areas of our research concern the diffusion in the silicon-germanium alloys and glassy materials such as silicon dioxide and ion conducting silicate glasses.
Date: November 14, 2004
Creator: Bracht, Hartmut A.; Silvestri, Hughes H. & Haller, Eugene E.
System: The UNT Digital Library
Study of scintillation, fluorescence and scattering in mineral oil for the MiniBooNE neutrino detector (open access)

Study of scintillation, fluorescence and scattering in mineral oil for the MiniBooNE neutrino detector

The MiniBooNE neutrino detector at Fermilab (FNAL) is filled with 250,000 gallons of pure mineral oil. The principal signal for MiniBooNE is light observed in a prompt Cherenkov cone. Scattering and fluorescence modify our detection of this light. Scintillation is also created by ionization in the oil. Studies of fluorescence of this oil have been carried out over a wide spectrum of exciting light and time resolved fluorescence with a narrower range of excitation. Polarized scattering measurements have been carried out at longer wavelengths. Time resolved and spectrally resolved scintillation has been studied with a 200 MeV Proton beam at the Indiana University Cyclotron Facility. Results of these studies will be reported.
Date: November 1, 2004
Creator: Brown, Bruce C.; Brice, Stephen; Hawker, Eric; Maza, Shannon; Meyer, Hans-Otto; Pla-Dalmau, Anna et al.
System: The UNT Digital Library
Integration of Renewables: Preprint (open access)

Integration of Renewables: Preprint

This is an overview of renewable energy technologies, especially those that can be used for distributed generation of electricity or heat. It This paper reviews the types of technologies, their present usage in the United States, their advantages in terms of resources, availability, modularity, emissions, and integration in distributed energy systems. It reviews some of the history of their use and projects their growth and cost.
Date: November 1, 2004
Creator: Bull, S.
System: The UNT Digital Library