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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Electron-helium scattering using analytical and numerical wave functions

kaurgurd@willettonshs.wa.edu.au, Gurdeep Kaur January 2002 (has links)
Theoretical investigations of electron-inert gas scattering are challenging because of the complex target structure. The electron-Helium system has been the most studied both at low and intermediate energies by sophisticated R-matrix and coupled channels methods. For the other inert gases, few calculations have been attempted at the same level sophistication. One problem is that general target-structure codes provide different forms of wave functions that must be interfaced with the scattering equations. The theoretical work presented in this thesis is based on the momentum-space coupled channels equations. For this formalism only one and two-electron atoms have been studied and purpose-built routines, specific to these atoms, have been developed. For the inert gases however such a task is much more formidable and a more practical approach is to use existing structure codes that have taken several man-years to develop. The framework of this thesis comprises of two parts. In the first part we discuss the need for, and the way to, modify the existing close-coupling code developed by Berge & Stelbovics in order to interface with other atomic structure packages in the literature. Two mainstream packages, an atomic structure package of Charlotte Froese Fischer and an atomic structure of Alan Hibbert are discussed. Methods to extract the wave functions for Helium and Neon targets using Hibbert's package are given. In the second part, various options and strategies for the calculation of the target structure, including frozen-core and configuration-interaction wave functions, using analytic Slater, Laguerre or numerical orbitals are considered for the Helium target. Hibbert's structure code wave functions are shown to be correctly interfaced into our momentum-space coupled channels code. The pros and cons of the various target structure descriptions are given and applied for lowenergy elastic and inelastic scattering of electron from Helium.
72

Transport d'électrons relativistes dans une cible solide : Etude du chauffage dans le cadre de l'allumage rapide.

Martinolli, Emanuele 24 April 2003 (has links) (PDF)
Ce travail de these s'inscrit dans le contexte des recherches sur la fusion par confinement inertiel. Il concerne plus particulierement le schema de l'allumage rapide, qui prevoit l'utilisation d'impulsions laser ultra-intenses pour amorcer les reactions nucleaires dans le combustible. Jusqu'a present, la faisabilite de ce scenario n'a pas encore ete prouvee. Il depend de nombreux aspects fondamentaux de la physique mise en jeu, qui ne sont pas encore entierement maıtrises. Dans ce travail, nous nous sommes proposes d'etudier experimentalement un des aspects fondamentaux de ce nouveau schema : le transport d'energie par les electrons relativistes crees par un faisceau laser ultra-intense.
73

Using the optical microscopy imaging method for studying electromigration /

Li, Linghong. January 2005 (has links)
Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 58-60).
74

Electron emission from surfaces resulting from low energy positron bombardment

Mukherjee, Saurabh. January 2008 (has links)
Thesis (Ph.D.) -- University of Texas at Arlington, 2008.
75

Energy relations in complex spectra

Inglis, David Rittenhouse, January 1900 (has links)
Thesis (Ph. D.)--University of Michigan, 1931. / From Physical review, v. 38, Sept. 1, 1931.
76

Numerical studies of strongly correlated electrons in transition metal oxides

Moraghebi, Mohammad. Moreo, Adriana. January 2003 (has links)
Thesis (Ph. D.)--Florida State University, 2003. / Advisor: Dr. Adriana Moreo, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed Apr. 9, 2004). Includes bibliographical references.
77

Neutrino electron plasma instability /

Lai, Chi-hsuan, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 53-56). Available also in a digital version from Dissertation Abstracts.
78

Measurement of neutral current electron-proton cross sections with longitudinally polarised electrons using the Zeus detector /

Noor, Syed Umer. January 2007 (has links)
Thesis (Ph.D.)--York University, 2007. Graduate Programme in Physics and Astronomy. / Typescript. Includes bibliographical references (leaves 224-234). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR39044
79

A measurement of the effective electron neutral current coupling parameters from polarized Bhabha scattering at the Z⁰ resonance /

Langston, Matthew D. January 2003 (has links)
Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 178-181). Also available for download via the World Wide Web; free to University of Oregon users.
80

Exact solutions for electron pairing models with spin-orbit interactions and Zeeman coupling

Liu, Jia, 刘佳 January 2013 (has links)
Although a number of methods with appropriate approximations, such as mean-field theory, local density approximation, and tight-binding method have been well developed and widely used in solid state physics, they possess strong limitations, and thus physicists never stop trying to find methods that could rigorously solve the models of condensed matter systems. This thesis presents several new exact solutions for electron pairing models with spin-orbit interactions and Zeeman coupling, which have not been studied before. First, a type of electron pairing model with spin-orbit interactions or Zeeman coupling is solved exactly in the framework of the Richardson’s previous work for 2D cases. Based on the exact solutions for the electron pairing model with spin-orbit interactions, it is shown rigorously that the pairing symmetry is of the p+ip wave and the ground state possesses time-reversal symmetry, which are expected by the meanfield theory. And the difference is that such peroration from our framework is valid for any strength of the pairing interactions. Intriguingly, how Majorana fermions can emerge is also elaborated in a ribbon system as well. Condensation energy and critical magnetic field are calculated in two systems with the exact solutions, and compared with the relevant results achieved by the mean-field theory, the differences between our results and the mean-field theory show the significance of the work for exact solutions. Secondly, we generalize our scenario to 3D cases. Several remarks of the 3D case are given following the significant results from the 2D cases. And an unconventional type of Fulde-Ferrel-Larkin-Ovchinnikov ground state is revealed exactly, in which the center-of-mass momentum of the fermion pair is proportional to the Zeeman field. As a by-product, a similar Fulde-Ferrel-Larkin-Ovchinnikov state is also disclosed when the magnetic field is in the same plane of k for 2D case. In addition, applying the transformative Richardson ansatz in bosonic system, we elaborate on the drifting effect of the Zeeman field on the spin-orbit-coupled Bose-Einstein condensed matter as well. Finally, we discuss the application of the exact solutions in quantum entanglement quantification. The entanglement monotone concurrence is calculated with exact solutions for two models. It is found to be a smooth function of pairing interactions, as expected. / published_or_final_version / Physics / Doctoral / Doctor of Philosophy

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