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An experimental investigation of stimulated Brillouin scattering in laser-produced plasmas relevant to inertial confinement fusion

Description: Despite the apparent simplicity of controlled fusion, there are many phenomena which have prevented its achievement. One phenomenon is laser-plasma instabilities. An investigation of one such instability, stimulated Brillouin scattering (SBS), is reported here. SBS is a parametric process whereby an electromagnetic wave (the parent wave) decays into another electromagnetic wave and an ion acoustic wave (the daughter waves). SBS impedes controlled fusion since it can scatter much or all of the i… more
Date: February 11, 1993
Creator: Bradley, K. S.
Partner: UNT Libraries Government Documents Department
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Exclusive B Decays into Final States with Two Charmed Baryons

Description: This Thesis presents measurements of the decays B{sup -} {yields} {Xi}{sub c}{sup 0}{bar {Lambda}}{sub c}{sup -}, {bar B}{sup 0} {yields} {Xi}{sub c}{sup +}{bar {Lambda}}{sub c}{sup -}, B{sup -} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}{sub c}{sup -} K{sup -}, and {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}{sub c}{sup -} K{sub s}{sup 0} based on 228 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factor… more
Date: January 11, 2010
Creator: Chai, Xuedong
Partner: UNT Libraries Government Documents Department
open access

Time Dependent Analysis of B to rho0rho0 Decays

Description: The BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider is located at the Stanford Linear Accelerator Center. It has been gathering data on the {Upsilon}(4S) resonance from 2000 until 2007 with the primary objective of studying CP violation in B-meson decays. In this thesis they provide a theoretical overview of how CP violation arises in the context of the Standard Model, why B decays are relevant, and how BABAR gathers the necessary data. Specifically, they present the an… more
Date: December 11, 2009
Creator: Osipenkov, Ilya Leonidovich
Partner: UNT Libraries Government Documents Department
open access

Resonant Inelastic X-ray Scattering of Rare-Earth and CopperSystems

Description: Rare earths and copper systems were studied using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). The use of monochromased synchotron radiation and improved energy resolution for RIXS made possible to obtain valuable information on the electronic structure in 4f, 5f and 3d systems. Experimental results for rare-earths (Ho, Gd, Cm, U, Np, Pu) were analyzed by atomic multiplet theory based on the Hartree-Fock calculations. The inelastic scattering structures in… more
Date: July 11, 2007
Creator: Kvashnina, Kristina
Partner: UNT Libraries Government Documents Department
open access

Understanding How Femtosecond Laser Waveguide Fabrication in Glasses Works

Description: In order to understand the physical processes associated with fs-laser waveguide writing in glass, the effects of the laser repetition rate, the material composition and feature size were studied. The resulting material changes were observed by collecting Raman and fluorescence spectra with a confocal microscope. The guiding behavior of the waveguides was evaluated by measuring near field laser coupling profiles in combination with white light microscopy. Waveguides and Bragg gratings were fabr… more
Date: May 11, 2006
Creator: Reichman, W J
Partner: UNT Libraries Government Documents Department
open access

Scintillation response of lithium fluoride

Description: Thesis. Lithium fluoride crystals, with TlF added to the charge, were prepared by the Bridgman- Stockbarger method. The scintillation response to photon energies between 25 and 1250 keV for these crystals and a commercially prepared LiF (Ti) crystal was studied. The response of the LiF (Ti) crystal was compared to the response of an NE109 scintillator at 1250 keV. The dose response of the LiF (Ti) crystal was evaluated over the energy range 25 to 1250 keV. The absorption and emission spectra of… more
Date: February 11, 1974
Creator: Kloepping, R.J.
Partner: UNT Libraries Government Documents Department
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Finding the Higgs boson of the standard model in the channel ZH → e<sup>+</sup>e<sup>-</sup>b$\bar{b}$ with the D0 detector at the Tevatron; Recherche du boson de Higgs du nideke standard dans le canal ZH → e<sup>+</sup>e<sup>-</sup>b$\bar{b}$ Avec le Detecteur DØ Aupres du Tevatron

Description: The organization of this thesis consists of three main ideas: the first presents the theoretical framework and experimental, as well as objects used in the analysis and the second relates to the various work tasks of service that I performed on the calorimeter, and the third is the search for the Higgs boson in the channel ZH → e<sup>+</sup>e<sup>-</sup>b$\bar{b}$. Thus, this thesis has the following structure: Chapter 1 is an introduction to the standard model of particle physics and the Higgs… more
Date: June 11, 2010
Creator: Calpas, Betty Constante
Partner: UNT Libraries Government Documents Department
open access

The interaction of intense subpicosecond laser pulses with underdense plasmas

Description: Laser-plasma interactions have been of interest for many years not only from a basic physics standpoint, but also for their relevance to numerous applications. Advances in laser technology in recent years have resulted in compact laser systems capable of generating (psec), 10{sup 16} W/cm{sup 2} laser pulses. These lasers have provided a new regime in which to study laser-plasma interactions, a regime characterized by L{sub plasma} {ge} 2L{sub Rayleigh} > c{tau}. The goal of this dissertation i… more
Date: May 11, 1995
Creator: Coverdale, C.A.
Partner: UNT Libraries Government Documents Department
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The intramolecular cyclization of bis-2,5-dimethylene-2,5-dihydrofurans and bis-2,5-dimethylene-2,5-dihydrothiophenes: An approach to macrocycles

Description: The first two papers of this dissertation present our work with the intramolecular cyclizations of a pair of p-quinodimethanes. The p-quinodimethanes were generated by flash vacuum pyrolysis (FVP) and were linked by a bridging chain. The third paper of this dissertation presents our work in the synthetic manipulation of the products formed from the intramolecular reactions of the p-quinodimethanes.
Date: January 11, 1994
Creator: Klumpp, D. A.
Partner: UNT Libraries Government Documents Department
open access

Development of a low-latency scalar communication routine on message-passing architectures

Description: One of the most significant advances in computer systems over the past decade is parallel processing. To be scalable to a large number of processing nodes and to be able to support multiple levels and forms of parallelism and its flexible use, new parallel machines have to be multicomputer architectures that have general networking support and extremely low internode communication latencies. The performance of a program when ported to a parallel machine is limited mainly by the internode commun… more
Date: January 11, 1994
Creator: Pai, R.
Partner: UNT Libraries Government Documents Department
open access

Equilibrium Speciation of Select Lanthanides in the Presence of Acidic Ligands in Homo- and Heterogeneous Solutions

Description: This dissertation explores lanthanide speciation in liquid solution systems related to separation schemes involving the acidic ligands: bis(2-ethylhexyl) phosphoric acid (HDEHP), lactate, and 8-hydroxyquinoline. Equilibrium speciation of neodymium (Nd3+), sodium (Na+), HDEHP, water, and lactate in the TALSPEAK liquid-liquid extraction system was explored under varied Nd3+ loading of HDEHP in the organic phase and through extraction from aqueous HCl and lactate media. System speciation was probe… more
Date: August 11, 2011
Creator: Robinson, Troy A.
Partner: UNT Libraries Government Documents Department
open access

MicroCantilever (MC) based nanomechanical sensor for detection of molecular interactions

Description: Specific aims of this study are to investigate the mechanism governing surface stress generation associated with chemical or molecular binding on functionalized microcantilevers. Formation of affinity complexes on cantilever surfaces leads to charge redistribution, configurational change and steric hindrance between neighboring molecules resulting in surface stress change and measureable cantilever deformation. A novel interferometry technique employing two adjacent micromachined cantilevers (a… more
Date: May 11, 2011
Creator: Kang, Kyung
Partner: UNT Libraries Government Documents Department
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