Studies of Band Structure and Free Carrier Scattering in Transparent Conducting Oxides Based on Combined Measurements of Electron Transport Phenomena (open access)

Studies of Band Structure and Free Carrier Scattering in Transparent Conducting Oxides Based on Combined Measurements of Electron Transport Phenomena

Experimental methods are discussed for studying band structure, effective mass, and other electronic properties relevant to mobility, including scattering mechanisms, relaxation time, and the influence of grain boundaries (GBs) in polycrystalline transparent conducting oxide (TCO) films. Impedance spectroscopy permits evaluation of the GB potential barrier height and density-of-states. These studies enable an estimate of the limiting mobility achievable for practical transparent conducting oxides to be made. The equipment for measurement of the four transport coefficients is discussed, and examples of its application to films of ZnO, SnO2, and Cd2SnO4 are given.
Date: October 31, 2000
Creator: Kaydanov, V. I.; Coutts, T. J. & Young, D. L.
System: The UNT Digital Library
MD Simulations of Carbonmonoxy Myoglobin and Calculations of Heme CD (open access)

MD Simulations of Carbonmonoxy Myoglobin and Calculations of Heme CD

None
Date: October 31, 2000
Creator: Woody, Robert W.; Kiefl, Christoph; Sreerama, Narasimha; Lu, Yi; Qiu, Yan & Shelnutt, John A.
System: The UNT Digital Library
Estimates of dispersive effects in a bent NLC Main Linac (open access)

Estimates of dispersive effects in a bent NLC Main Linac

An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow a gravitational equipotential. The authors begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bending of the beam to follow an equipotential surface, and an introduction of sharp bends at a few sites in the linac so as to reduce the maximum sagitta produced.
Date: October 31, 2000
Creator: Michelotti, Michael Syphers and Leo
System: The UNT Digital Library
IFSAR for the Rapid Terrain Visualization Demonstration (open access)

IFSAR for the Rapid Terrain Visualization Demonstration

The Rapid Terrain Visualization Advanced Concept Technology Demonstration (RTV-ACTD) is designed to demonstrate the technologies and infrastructure to meet the Army requirement for rapid generation of digital topographic data to support emerging crisis or contingencies. The primary sensor for this mission is an interferometric synthetic aperture radar (IFSAR) designed at Sandia National Laboratories. This paper will outline the design of the system and its performance, and show some recent flight test results. The RTV IFSAR will meet DTED level III and IV specifications by using a multiple-baseline design and high-accuracy differential and carrier-phase GPS navigation. It includes innovative near-real-time DEM production on-board the aircraft. The system is being flown on a deHavilland DHC-7 Army aircraft.
Date: October 31, 2000
Creator: BURNS,BRYAN L.; EICHEL,PAUL H.; HENSLEY JR.,WILLIAM H. & KIM,THEODORE J.
System: The UNT Digital Library
Soft and hard interactions in p {bar p} collisions at {radical}s = 1800 and 630 GeV (open access)

Soft and hard interactions in p {bar p} collisions at {radical}s = 1800 and 630 GeV

Proton-antiproton events collected with the CDF minimum-bias trigger at {radical}(s) = 1800 and 630 GeV are studied splitting the full event sample in a soft subsample of events with no energy clusters above 1.1 GeV and in the subsample of the remaining events. Detailed and precise analyses of the multiplicity and transverse momentum distributions as well as of the correlation of the average pt and of its dispersion with the multiplicity are performed for the two samples. Comparisons of the results and of their dependence from the center of mass energy show clear differences in their behaviors. The results support important and unexpected scaling properties of the soft sample.
Date: October 31, 2000
Creator: Rimondi, Franco
System: The UNT Digital Library
Measurement of d{sigma}/dy for high mass Drell-Yan e+ e- pairs at CDF (open access)

Measurement of d{sigma}/dy for high mass Drell-Yan e+ e- pairs at CDF

None
Date: October 31, 2000
Creator: Bodek, Atie
System: The UNT Digital Library
Conformational Analysis of the Non-Planar Deformations of Cobalt Porphyrin Complexes in the Cambridge Structural Database (open access)

Conformational Analysis of the Non-Planar Deformations of Cobalt Porphyrin Complexes in the Cambridge Structural Database

None
Date: October 31, 2000
Creator: Cullen, David L; Desai, Lopa V.; Zimmer, Marc & Shelnutt, John A.
System: The UNT Digital Library
PreFPIX2: Core architecture and results (open access)

PreFPIX2: Core architecture and results

None
Date: October 31, 2000
Creator: al., James R. Hoff et
System: The UNT Digital Library
Grid technologies and applications : architecture and achievements. (open access)

Grid technologies and applications : architecture and achievements.

None
Date: October 31, 2001
Creator: Foster, I.
System: The UNT Digital Library
Quantum Algorithm for Continuous Global Optimization (open access)

Quantum Algorithm for Continuous Global Optimization

We investigate the entwined roles of information and quantum algorithms in reducing the complexity of the global optimization problem (GOP). We show that: (1) a modest amount of additional information is sufficient to map the general continuous GOP into the (discrete) Grover problem; (2) while this additional information is actually available in some classes of GOPs, it cannot be taken advantage of within classical optimization algorithms; (3) on the contrary, quantum algorithms over a natural framework for the efficient use of this information resulting in a speed-up of the solution of the GOP.
Date: October 31, 2001
Creator: Protopopescu, V
System: The UNT Digital Library
Masses, lifetimes, and decays of B hadrons at the Tevatron (open access)

Masses, lifetimes, and decays of B hadrons at the Tevatron

The latest results in B physics from the CDF and D0 experiments at the Tevatron are presented, including inclusive b lifetime measurement, exclusive lifetime measurement of the B{sub s}. Promising samples collected by CDF with its Secondary Vertex Trigger are shown as well.
Date: October 31, 2003
Creator: Vacavant, L.
System: The UNT Digital Library
Results on intense beam focusing and neutralization from the neutralized beam experiment (open access)

Results on intense beam focusing and neutralization from the neutralized beam experiment

We have demonstrated experimental techniques to provide active neutralization for space-charge dominated beams as well as to prevent uncontrolled ion beam neutralization by stray electrons. Neutralization is provided by a localized plasma injected from a cathode arc source. Unwanted secondary electrons produced at the wall by halo particle impact are suppressed using a radial mesh liner that is positively biased inside a beam drift tube. We present measurements of current transmission, beam spot size as a function of axial position, beam energy and plasma source conditions. Detailed comparisons with theory are also presented.
Date: October 31, 2003
Creator: Roy, P. K.; Yu, S. S.; Eylon, S.; Henestroza, E.; Anders, A.; Bieniosek, F. M. et al.
System: The UNT Digital Library
B and c quark production at CDF, {radical} s = 1.96 TeV (open access)

B and c quark production at CDF, {radical} s = 1.96 TeV

Measurements of heavy quark production at the Tevatron have previously shown discrepancies with theoretical predictions. The increased luminosity of Run 2 will allow CDF to investigate b and c quark production more precisely. In this review three measurements, based on a subset of current data are presented: charm meson production; J/{psi} production; production of an energetic photon in conjunction with a b or c quark jet.
Date: October 31, 2003
Creator: Shears, T.
System: The UNT Digital Library
Hard QCD at the Tevatron (open access)

Hard QCD at the Tevatron

Results from QCD studies at the Tevatron from new Run 2 data are presented. The inclusive jet cross section and dijet mass spectrum are measured at {radical}s = 1960 GeV by the CDF and D0 collaborations. CDF also reports results of searches for new particles decaying into dijets, and a study of jet shapes.
Date: October 31, 2003
Creator: Mesropian, C.
System: The UNT Digital Library
Technology choices for the Integrated Beam Experiment (IBX) (open access)

Technology choices for the Integrated Beam Experiment (IBX)

Over the next three years the research program of the Heavy Ion Fusion Virtual National Laboratory (HIF-VNL), a collaboration among LBNL, LLNL, and PPPL, is focused on separate scientific experiments in the injection, transport and focusing of intense heavy ion beams at currents from 100 mA to 1 A. As a next major step in the HIF-VNL program, we aim for a complete ''source-to-target'' experiment, the Integrated Beam Experiment (IBX). By combining the experience gained in the current separate beam experiments IBX would allow the integrated scientific study of the evolution of a single heavy ion beam at high current ({approx}1 A) through all sections of a possible heavy ion fusion accelerator: the injection, acceleration, compression, and beam focusing. This paper describes the main parameters and technology choices of the planned IBX experiment. IBX will accelerate singly charged potassium or argon ion beams up to 10 MeV final energy and a longitudinal beam compression ratio of 10, resulting in a beam current at target of more than 10 Amperes. Different accelerator cell design options are described in detail: Induction cores incorporating either room temperature pulsed focusing-magnets or superconducting magnets.
Date: October 31, 2002
Creator: Leitner, M. A.; Celata, C. M.; Lee, E. P.; Sabbi, G.; Waldron, W. L. & Barnard, J. J.
System: The UNT Digital Library
Extruding plastic scintillator at Fermilab (open access)

Extruding plastic scintillator at Fermilab

An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R&D program at Fermilab.
Date: October 31, 2003
Creator: Pla-Dalmau, Anna; Bross, Alan D. & Rykalin, Victor V.
System: The UNT Digital Library
Corrosion of Exhaust and Filtration Equipment in a Radioactive Waste Incinerator (open access)

Corrosion of Exhaust and Filtration Equipment in a Radioactive Waste Incinerator

Condensation in the exhaust gas system of an incinerator burning low activity radioactive wastes led to numerous corrosion developments and rapid failure of the discharge filters. The problem was traced to insufficient reheat of the exhaust gases following scrubbing. Rust particulate and moisture loaded the filters, leading to water accumulation, chloride cracking of the filter housings, and plugging and tearing of the filter media itself. To mitigate the problem, the exhaust gas temperature was increased, thermal insulation was installed on the ductwork, and the interiors of the ducts and new filter housings were lined with a protective coating.
Date: October 31, 2003
Creator: Jenkins, C. F.
System: The UNT Digital Library
Very high power THz radiation sources (open access)

Very high power THz radiation sources

We report the production of high power (20 watts average, {approx} 1 Megawatt peak) broadband THz light based on coherent emission from relativistic electrons. Such sources are ideal for imaging, for high power damage studies and for studies of non-linear phenomena in this spectral range. We describe the source, presenting theoretical calculations and their experimental verification. For clarity we compare this source to one based on ultrafast laser techniques.
Date: October 31, 2002
Creator: Carr, G. L.; Martin, Michael C.; McKinney, Wayne R.; Jordan, K.; Neil, George R. & Williams, G. P.
System: The UNT Digital Library
Search for new particles or gauge bosons decaying into dileptons/dijets at the Tevatron (open access)

Search for new particles or gauge bosons decaying into dileptons/dijets at the Tevatron

The existence of new particles decaying in a jet or lepton pair is probed with the Run II data collected by the Tevatron p{bar p} collider at {radical}s = 1.96 TeV. Searches performed on both jet and lepton data collected by the CDF and D0 detectors do not show signs of any new resonance within the considered mass range. The sensitivity achieved by these searches leads to 95% C.L. limits on the production cross-section times branching ratio for axigluons, flavour universal colorons, excited quarks, colour octet techni-{rho}, E{sub 6} diquarks, new gauge bosons and Randall-Sundrum gravitons. Excluded mass regions for these models are also computed.
Date: October 31, 2003
Creator: Giordani, M. P.
System: The UNT Digital Library
Field flatness tuning of TM110 mode cavities with closely spaced modes (open access)

Field flatness tuning of TM110 mode cavities with closely spaced modes

Superconducting cavities for the CKM RF separated kaon beamline at Fermilab have modes that are closely spaced compared to the resonance bandwidths when warm, and this complicates the field flatness (warm) tuning process. Additionally, it is necessary to maintain the azimuthal orientation of the mode during the tuning deformations. the authors present two analytic techniques to warm-tune cavities with overlapping modes, a finite-element analysis of the tuning process, the design of a warm tuner which maintains mode polarization, and the results of tuning a cavity in which initial manufacturing variations caused the desired {pi} and nearby {pi}-1 modes to be indistinguishable before field flatness tuning.
Date: October 31, 2003
Creator: al., Leo Bellantoni et
System: The UNT Digital Library
The 2.6 Angstrom resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position' (open access)

The 2.6 Angstrom resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position'

None
Date: October 31, 2001
Creator: Cobessi, D.; Huang, L.-S.; Ban, M.; Pon, N. G.; Daldal, F. & Berry, E. A.
System: The UNT Digital Library
A worldsheet description of large N{sub c} quantum field theory (open access)

A worldsheet description of large N{sub c} quantum field theory

None
Date: October 31, 2001
Creator: Bardakci, Korkut & Thorn, Charles B.
System: The UNT Digital Library
Development of Interfacial Structure in a Confined Air-Water Cap-Turbulent and Churn-Turbulent Flow (open access)

Development of Interfacial Structure in a Confined Air-Water Cap-Turbulent and Churn-Turbulent Flow

The objective of the present work is to study and model the interfacial structure development of air-water two-phase flow in a confined test section. Experiments of a total of 9 flow conditions in a cap-turbulent and churn-turbulent flow regimes are carried out in a vertical air-water upward two-phase flow experimental loop with a test section of 20-cm in width and 1-cm in gap. The miniaturized four-sensor conductivity probes are used to measure local two-phase parameters at three different elevations for each flow condition. The bubbles captured by the probes are categorized into two groups in view of the two-group interfacial area transport equation, i.e., spherical/distorted bubbles as Group 1 and cap/churn-turbulent bubbles as Group 2. The acquired parameters are time-averaged local void fraction, interfacial velocity, bubble number frequency, interfacial area concentration, and bubble Sauter mean diameter for both groups of bubbles. Also, the line-averaged and area-averaged data are presented and discussed. The comparisons of these parameters at different elevations demonstrate the development of interfacial structure along the flow direction due to bubble interactions.
Date: October 31, 2001
Creator: Sun, X.; Kim, S.; Cheng, L.; Ishii, M. & Beus, S.G.
System: The UNT Digital Library
Implosion of indirectly driven reentrant cone shell target (open access)

Implosion of indirectly driven reentrant cone shell target

In an x-ray driven reentrant cone fast ignition target the x-ray spectrum contains a high energy component that casuses preheating of the reentrant cone and mixing of the gold into the collapsing shell. Direct laser drive might avoid this problem.
Date: October 31, 2003
Creator: Stephens, R. B.; Hatchett, S. P.; Turner, R. E.; Tanaka, K. A. & Kodama, R.
System: The UNT Digital Library