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The Dyad Theory Of Classical And Quantum Physics, Preston Jones

Publications

The 4-space equations of hydrodynamics, electrodynamics, and quantum mechanics are developed using the dyad calculus. Gravity is found to couple hydrodynamics, electrodynamics, and quantum mechanics through the 4- space metric and differential operator. Expanding the 4-space equations of electrodynamics a time varying metric is shown to dissipate electromagnetic energy.

A Hybrid Lagrangian Variational Method For Bose–Einstein Condensates In Optical Lattices, Mark Edwards, Lisa M. Debeer, Mads Demenikov, Jacob Galbreath, T. Joseph Mahaney, Bryan Nelsen, Charles W. Clark

Physics & Astronomy: Faculty Publications

Solving the Gross–Pitaevskii (GP) equation describing a Bose–Einstein condensate (BEC) immersed in an optical lattice potential can be a numerically demanding task. We present a variational technique for providing fast, accurate solutions of the GP equation for systems where the external potential exhibits rapid variation along one spatial direction. Examples of such systems include a BEC subjected to a one-dimensional optical lattice or a Bragg pulse. This variational method is a hybrid form of the Lagrangian variational method for the GP equation in which a hybrid trial wavefunction assumes a Gaussian form in two coordinates while being totally unspecified in …

Complex Energy Shift And Background Phase Shift For Simulated Electron-Molecular Shape Resonances, Gordon A. Gallup

Gordon Gallup Publications

Feshbach-Fano resonance theory (FFRT) is used to determine the energy dependence of the complex energy shift function, consisting of the real energy shift and the resonance width, and the background phase shift for several simulated molecular shape resonances. Attention is paid to the way the choice of the quasibound state (QBS) function required in the FFRT affects these energy dependencies. An overlap criterion for choosing an optimal QBS function is proposed. Using our treatment on t-butylchloride, carbon tetrachloride, ethylene, and benzene, we give numerical results for specific cases of l = 1 through 4. We find that the real …

Measurement Of W Γ And Z Γ Production In Pp̅ Collisions At √S =1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

The standard model predictions for W γ and Z γ production are tested using an integrated luminosity of 200 pb-1 of pp̅ 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 ET>7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W γ and Zγ data are compared to SM predictions.

Search For Supersymmetry With Gauge-Mediated Breaking In Diphoton Events At D0, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb^-1 of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002–2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest …

Comparison Of Three-Jet Events In Pp̅ Collisions At √S = 1.8 Tev To Predictions From A Next-To-Leading Order Qcd Calculation, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

The properties of three-jet events with total transverse energy greater than 320 GeV and individual jet energy greater than 20 GeV have been analyzed and compared to absolute predictions from a next-to-leading order (NLO) perturbative QCD calculation. These data, of integrated luminosity 86 pb^-1, were recorded by the CDF Experiment for pp̅ collisions at √s = 1.8 TeV. This study tests a model of higher order QCD processes that result in gluon emission and may give some indication of the magnitude of the contribution of processes higher than NLO. The total cross section is measured to be 466±3(stat.) …

Measurement Of The J/ Ψ Meson And B-Hadron Production Cross Sections In Pp̅ Collisions At √S =1960 Gev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a new measurement of the inclusive and differential production cross sections of J/ψ mesons and b hadrons in proton-antiproton collisions at √s=1960 GeV. The data correspond to an integrated luminosity of 39.7 pb^-1l collected by the CDF run II detector. We find the integrated cross section for inclusive J/ψ production for all transverse momenta from 0 to 20 GeV/c in the rapidity range |y|-0.33^+0.36 (syst) µb. We separate the fraction of J/ψ events from the decay of the long-lived b hadrons using the lifetime distribution in all events with p_T( …

Laser Based Synchrotron Radiation, Kim Ta Phuoc, Frederic Burgy, Jean-Philippe Rousseau, Victor Malka, Antoine Rousse, Rahul Shah, Donald P. Umstadter, Alexander Puhkov, Sergei Kiselev

Donald Umstadter Publications

Beams of x rays in the kiloelectronvolt energy range have been produced from laser-matter interaction. Here, energetic electrons are accelerated by a laser wakefield, and experience betatron oscillations in an ion channel formed in the wake of the intense femtosecond laser pulse. Experiments using a 50 TW laser (30 fs duration) are described, as well as comparisons with numerical simulations. These results pave the way of a new generation of radiation in the x-ray spectral range, with a high collimation and an ultrafast pulse duration, produced by the use of compact laser system.

The Perpendicular Magnetic Anisotropy Of Copt/Au Multilayer Films, T. Yokota, Lei Gao, R. Zhang, Leighann Nicholl, M. L. Yan, David J. Sellmyer, Sy-Hwang Liou

Sy-Hwang Liou Publications

We have studied the magnetic properties of Au (2 nm)/Co₅₀Pt₅₀ (3 nm)/Au (2 nm) multilayer films prepared on amorphous Al₂O₃/Si and (0 0 1) MgO substrates. The as-deposited films on both substrates are magnetically soft with an FCC structure and exhibit a perpendicular anisotropy. After annealing at 500 °C, the sample on the Al₂O₃/Si substrate has become magnetically isotropic but the sample on the MgO substrate still has perpendicular anisotropy with FCT structure. This film deposited on the MgO substrate did not show a strong perpendicular anisotropy due to …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, S. Kolesnikov, E. Shwageraus, A. Galperin

Fuels Campaign (TRP)

This report presents the results of the Task 3, defined in working program as: evaluation of burnable poison designs. Adopting the basic design of a standard PWR and Pu loadings required for 18-month cycle (results of Task 2), this part of the program is aimed to estimate performance of each BP design and BP material to address challenges of Fertile-Free Fuel (FFF) Concept. Finally, an optimal BP design will be developed and an overall feasibility of FFF concept will be determined. Basically, the main challenge encountered in neutronic design for a FFF core is to develop reactivity control system which …

Hybrid Explicit-Implicit Fdtd-Fem Time-Domain Solver For Electromagnetic Problems, Kakhkhor Abdijalilov

Dissertations

The Finite-Difference Time-Domain (FDTD) method and Finite-Element (FEM) method are numerical techniques used for solving Maxwell's electromagnetic equations. FDTD-FEM hybrid methods opt for combining the advantages of both FDTD and FEM. In this dissertation, signal processing techniques were used to analyze the FDTD stability condition. A procedure, which reduces time-sampling error yet preserves the stability of algorithm is proposed. Both explicit and implicit time-stepping schemes were treated in the framework of the developed method. An improved version of the implicit-explicit FEM-FDTD hybrid method was developed. The new method minimizes reflection from the interface between different types of grids. A class …

Search For Electroweak Single-Top-Quark Production In Pp̅ Collisions At √S =1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on a search for standard model t-channel and s-channel single-top quark production in pp̅ collisions at a center of mass energy of 1.96 TeV. We use a data sample corresponding to 162 pb^-1 recorded by the upgraded collider detector at Fermilab. We find no significant evidence for electroweak top quark production and set upper limits at the 95% confidence level on the production cross section, consistent with the standard model: 10.1 pb for the t-channel, 13.6 pb for the s-channel and 17.8 pb for the combined cross section of t- and s …

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing: Quarterly Progress Report #1, Jamil M. Renno, Georg F. Mauer

Fuels Campaign (TRP)

A Hot Cell robotic assembly: Pick and place dynamic simulation, including feedback control with Matlab, was developed for dispersion fuel manufacture.

The deployment of remote manufacturing of transmuter fuel is a necessity for the transmutation applications. In the reporting period, a virtual hot cell for the manufacturing of dispersion fuel was designed using MSC.visualNastran^©, ProEngineer^© and MATLAB^©. Atypical events were successfully simulated. Relevant physical quantities arising during such events were monitored as well.

Exploring Optimization For The Random-Field Ising Model, Alan Middleton, D. Clay Hambrick, Jan H. Meinke

Physics - All Scholarship

The push-relabel algorithm can be used to calculate rapidly the exact ground states for a given sample with a random-field Ising model (RFIM) Hamiltonian. Although the algorithm is guaranteed to terminate after a time polynomial in the number of spins, implementation details are important for practical performance. Empirical results for the timing in dimensions d=1,2, and 3 are used to determine the fastest among several implementations. Direct visualization of the auxiliary fields used by the algorithm provides insight into its operation and suggests how to optimize the algorithm. Recommendations are given for further study of the RFIM.

Optical Spectroscopy Of The Surface Population Of The Ρ Ophiuchi Molecular Cloud: The First Wave Of Star Formation, Bruce Wilking, Michael Meyer, John Robinson, Thomas Greene

Physics Faculty Works

We present the results of optical spectroscopy of 139 stars obtained with the Hydra multiobject spectrograph. The objects extend over a 1.3 deg2 area surrounding the main cloud of the ρ Oph complex. The objects were selected from narrowband images to have Hα in emission. Using the presence of strong Hα emission, lithium absorption, location in the Hertzsprung-Russell diagram, or previously reported X-ray emission, we were able to identify 88 objects as young stars associated with the cloud. Strong Hα emission was confirmed in 39 objects with line widths consistent with their origin in magnetospheric accretion columns. Two of the …

Isomeric Decay Of 208Ra, J. J. Ressler, C. W. Beausang, H. Ai, H. Amro, M. Babilon, J. A. Caggiano, R. F. Casten, G. Gurdal, A. Heinz, R. O. Hughes, E. A. Mccutchan, D. A. Meyer, C. Plettner, J. Qian, M.J. S. Sciacchitano, N. J. Thomas, E. Williams, N. V. Zamfir

Physics Faculty Publications

Low-energy excited states of 208Ra were investigated using the 182W(30Si, 4n) reaction at the Wright Nuclear Structure Laboratory of Yale University. Fusion evaporation recoils were selected using the gas-filled spectrometer SASSYER. Delayed γ rays, following isomeric decays, were detected at the focal plane of SASSYER with a small array of three clover Ge detectors. Transitions following a proposed J π = 8+ isomer were observed, and the half-life was measured.

Current-Spin Coupling For Ferromagnetic Domain Walls In Fine Wires, S. E. Barnes, S. Maekawa

Physics Articles and Papers

The coupling between a current and a domain wall is examined. In the presence of a finite current and in the absence of a potential which breaks the translational symmetry, there is a perfect transfer of angular momentum from the conduction electrons to the wall. As a result, the ground state is in uniform motion and this remains the case even when relaxation is included. This is described by, appropriately modified, Landau-Lifshitz-Gilbert equations. The results for a simple pinning model are compared with experiment.

Ab Initio Study Of Ferromagnetism In Ga1−Xcrxn Thin Films, Qin Wang, Q. Sun, Puru Jena, J. Z. Yu, R. Note, Y. Kawazoe

Physics Publications

Electronic structure and magnetic properties of Ga1-xCrxN thin films are studied using the gradient corrected density functional method and a supercell slab model. Calculations are carried out by varying the concentration of doped Cr atoms and the sites they occupy. Cr atoms are found to prefer to reside on the surface sites and cluster around N as Mn atoms do. However, unlike Mn-doped GaN, Cr-doped GaN is found to be ferromagnetic for all concentrations studied. The calculated ferromagnetism is in agreement with recent experimental observations.

Evolution Of The Electronic Structure Of Be Clusters, V. Cerowski, B. K. Rao, S. K. Khanna, P. Jena, Soh Ishii, Kaoru Ohno, Yoshiyuki Kawazoe

Physics Publications

Using a modified symbiotic genetic algorithm approach and many-body interatomic potential derived from first principles, we have calculated equilibrium geometries and binding energies of the ground-state and low-lying isomers of Be clusters containing up to 41 atoms. Molecular-dynamics study was also carried out to study the frequency of occurrence of the various geometrical isomers as these clusters are annealed during the simulation process. For a selected group of these clusters, higher-energy isomers were more often found than their ground-statestructures due to large catchment areas. The accuracy of the above ground-stategeometries and their corresponding binding energies were verified by carrying out …

Vlba Polarization Observations Of Markarian 421 After A Gamma-Ray High State, B. Glenn Piner, Philip G. Edwards

Physics

We present four high dynamic range, dual-circular polarization, Very Long Baseline Array (VLBA) observations at 22 GHz of Mrk 421, taken throughout the year following the source's unprecedented gamma-ray high state in early 2001. Previous VLBI observations of this source had shown only subluminal apparent motions in the parsec-scale jet and no apparent connection between jet components and gamma-ray flares, so we examined whether the larger gamma-ray flares of 2001 had produced a component that could be followed on the parsec-scale VLBA images. These four new VLBA observations are combined with data from our earlier 1999 paper and archival VLBA …

Prototype Of Fault Adaptive Embedded Software For Large-Scale Real-Time Systems, Derek Messie, Mina Jung, Jae C. Oh, Shweta Shetty, Steven Nordstrom, Michael Haney

Electrical Engineering and Computer Science - All Scholarship

This paper describes a comprehensive prototype of large-scale fault adaptive embedded software developed for the proposed Fermilab BTeV high energy physics experiment. Lightweight self-optimizing agents embedded within Level 1 of the prototype are responsible for proactive and reactive monitoring and mitigation based on specified layers of competence. The agents are self-protecting, detecting cascading failures using a distributed approach. Adaptive, reconfigurable, and mobile objects for reliability are designed to be self-configuring to adapt automatically to dynamically changing environments. These objects provide a self-healing layer with the ability to discover, diagnose, and react to discontinuities in real-time processing. A generic modeling environment …

Importance Of Accurate Computation Of Secondary Electron Emission For Modelingspacecraft Charging, Sebastien Clerc, John R. Dennison

All Physics Faculty Publications

The secondary electron yield is a critical process in establishing the charge balance in spacecraft charging and the subsequent determination of the equilibrium potential. Spacecraft charging codes use a parameterized expression for the secondary electron yield δ(Eo) as a function of incident electron energy, Eo. A critical step in accurately characterizing a particular spacecraft material is establishing the most efficient and accurate way to determine the fitting parameters in terms of the measured electron yield data and physics-based theoretical models. Simple two- or three- step physics models of the electron penetration, transport and emission from a solid are typically expressed …

A New Search For The Neutron Electric Dipole Moment, Crystal Storey

Theses & Honors Papers

The next generation experiments to measure the neutron EDM are being proposed at the Los Alamos National Lab. The use of spin polarized ³He is a critical component of the experiment. Thus measuring the relaxation times of polarized ³He under the actual conditions of the neutron EDM is a crucial step in the success of the experiment. This paper talks about the effort underway at Duke University to measure the relaxation time of polarized ³He at cryogenic temperatures. The applications available in LabView and ExpressPCB have been used extensively in these efforts.

Magnetic Coupling Between Cr Atoms Doped At Bulk And Surface Sites Of Zno, Q. Wang, Q. Sun, Puru Jena, Y. Kawazoe

Physics Publications

Contrary to theoretical prediction that Cr-doped bulk ZnO is ferromagnetic, recent experiments on Cr-doped ZnOthin film reveal the coupling to be antiferromagnetic. Using first-principles calculations based on gradient corrected density functional theory, we show that a possible origin of this disagreement may be associated with the site preference of Cr. In bulk, when Cr substitutes Zn,bond contraction occurs and Cr atoms prefer to cluster around O atoms. The ferromagnetic coupling among Cr atoms is driven by Cr 3d and O 2p exchange interactions as in Cr2O cluster. However, when Cr atoms replace Zn on the surface, due to the different …

A Solution To Symmetric Teleparallel Gravity, Muzaffer Adak, Özcan Sert

Turkish Journal of Physics

Teleparallel gravity models, in which the curvature and the nonmetricity of spacetime are both set zero, are widely studied in the literature. We work a different teleparallel theory, in which the curvature and the torsion of spacetime are both constrained to zero, but the nonmetricity is nonzero. After reformulating the general relativity in this spacetime we find a solution and investigate its singularity structure.

Spin-Dependent Transport In Fe And Fe/Au Multilayers, Theodore L. Monchesky, Axel Enders, R. Urban, Kenneth Myrtle, Brett Heinrich, X.-G. Zhang, William H. Butler, J. Kirschner

Axel Enders Publications

In situ resistance measurements of epitaxial Fe layers and Au/Fe bilayers were used to quantify the scattering in giant magnetoresistance (GMR) spin valve structures. The semiclassical Boltzmann transport equation, incorporating first-principles local density functional calculations, fitted the thickness dependence of the conductivity. Fits to the data indicate that Fe has a large spin asymmetry with bulk relaxation times τ↓=3.0 × 10⁻¹⁴ s and τ↑=2.5 × 10⁻¹⁵ s. These give a conductivity equal to that of bulk Fe. The interface scattering from the Fe/GaAs, the Fe/vacuum, and the Au/vacuum interfaces is purely diffuse. This is in contrast to the …

The Potential Of Vibrational Spectroscopy In The Early Detection Of Cervical Cancer: An Exciting Emerging Field, Eoghan O'Faolain, Mary Hunter, Joe Byrne, Peter Kelehan, Hugh Byrne, Fiona Lyng

Conference papers

The application of vibrational spectroscopy to disease diagnosis is a relatively new, rapidly evolving scientific field. Techniques such as Raman and infrared spectroscopy have shown great promise in this regard over the past number of years. This study directly compared Raman spectroscopy and synchrotron infrared (SR-IR) spectroscopy on parallel cervical cancer samples. Both frozen and dewaxed formalin fixed paraffin preserved tissue sections were examined. Both tissue types produced good quality Raman and SR-IR spectra, although the lesser processed, frozen tissue sections displayed the most detailed spectra. Spectroscopy was shown capable of discriminating between different cell types in normal cervical tissue. …

Polar F-Layer Model-Observation Comparisons: A Neutral Wind Surprise, Jan Josef Sojka, M. David, Robert W. Schunk, A. P. Van Eyken

All Physics Faculty Publications

The existence of a month-long continuous database of incoherent scatter radar observations of the ionosphere from the EISCAT Savlbard Radar (ESR) at Longyearbyen, Norway, provides an unprecedented opportunity for model/data comparisons. Physics-based ionospheric models, such as the Utah State University Time Dependent Ionospheric Model (TDIM), are usually only compared with observations over restricted one or two day events or against climatological averages. In this study, using the ESR observations, the daily weather, day-to-day variability, and month-long climatology can be simultaneously addressed to identify modeling shortcomings and successes. Since for this study the TDIM is driven by climatological representations of the …

A New Global Average Model Of The Coupled Thermosphere And Ionosphere, C. G. Smithtro, Jan Josef Sojka

All Physics Faculty Publications

A model representing the global average ionosphere and thermosphere (GAIT) is developed as a tool to explore the response of the coupled system to changes in the input solar irradiance between 3 and 360 nm. The GAIT model self-consistently solves the coupled continuity, momentum, and energy equations for the three major neutral species, N₂, O₂, and O, as well as minor neutral constituents important to the global energy budget. In the ionosphere the model includes five different ion species and two excited states of O⁺. The GAIT model also includes an approximate treatment of …

Structural Growth In Iron Oxide Clusters: Rings, Towers, And Hollow Drums, N. O. Jones, B. V. Reddy, F. Rasouli, Shiv N. Khanna

Physics Publications

It is shown that the transition from an elementary FeO molecule to the bulk rock-salt FeO proceeds via hollow rings, towers, and drums. Our first-principles electronic structure calculations carried out within a gradient-corrected density functional framework show that small FenOn (n=2,3,4,5) clusters form single, highly stable rings. Starting at Fe6O6, these elementary rings begin to assemble into nano columnar structures to form stable Fe6O6, Fe7O7, Fe8O8, Fe9O9, Fe10O10, and Fe12O12 towers. The rings and the empty towers can be further stabilized by capping O atoms at the ends, leading to FenOn+1 and FenOn+2 sequences. The theoretical results provide insight into …