Left unprotected, both transmissive and reflective final optics in a laser-driven inertial fusion power plant would quickly fail from melting, pulsed thermal stress, or degradation of optical properties as a result of ion implantation. One potential option for mitigating this threat is to magnetically deflect the ions such that they are directed to a robust energy dump. In this paper we detail integrated studies that have been carried out to assess the viability of this approach for protecting final optics.

The authors present a measurement of B({pi}{sup 0} {yields} e{sup +}e{sup -}{gamma})/B({pi}{sup 0} {yields} {gamma}{gamma}) using data taken in 1999 by the E832 KTeV experiment at Fermilab. The {pi}{sup 0}s were produced by K{sub L} decays in flight that are fully reconstructed. They find 63,693 K{sub L} {yields} 3{pi}{sup 0} {yields} {gamma}{gamma} {gamma}{gamma} e{sup +}e{sup -}{gamma} decays in KTeV data (an increase of a factor of {approx} 20 in event statistics over previous experiments), and normalize to K{sub L} {yields} 3{pi}{sup 0} {yields} 6{gamma}, to extract B({pi}{sup 0} {yields} e{sup +}e{sup -}{gamma}, m{sub e{sup +}e{sup -}} > 15 MeV/c{sup 2})/B({pi}{sup 0} {yields} {gamma}{gamma}) = (3.920 {+-} 0.016 {+-} 0.036) x 10{sup -3}, where the first error is statistical and the second is systematic. Using the Mikaelian and Smith prediction for the e{sup +}e{sup -} mass spectrum as implemented in the KTeV Monte Carlo to correct to the full e{sup +}e{sup -} mass range yields B({pi}{sup 0} {yields} e{sup +}e{sup -}{gamma})/B({pi}{sup 0} {yields} {gamma}{gamma}) = (1.1559 {+-} 0.0046 {+-} 0.0107)%. This result is consistent with previous measurements and with theoretical predictions, and the uncertainty is a factor of three smaller than any previous measurement.

None

A large diameter precision air bearing rotary table with a 16.0 inch diameter through-hole was designed, fabricated and tested in the course of this research. The rotary table will be used in conjunction with a specialized, computer controlled precision inspection machine being designed for the Department of Energy`s (DOE) Nuclear Weapons Complex (NWC). The design process included a complete engineering analysis to predict the final performance of the rotary table, and to ensure that the rotary table meets the required accuracy of 4.0 microinches of total radial (3.5 microinches average radial) and 4.0 microinches total axial (3.5 microinches average axial) errors. The engineering analysis included structural deformation, thermal sensitivity and dynamic analyses using finite element methods in some cases, as well as other analytic solutions. Comparisons are made between predicted and tested values, which are listed in the rotary table error budget. The rotary table performed as predicted with measured axial and radial stiffnesses of 1.1E06 lbf/inch and 2.9E06 lbf/inch, respectively, as well as average radial, axial and tilt errors of 2.5 microinches, 1.5 microinches, and less than 0.05 arcseconds, respectively.

None

The morphological evolution of cylindrical pores or ``channels`` and crack-like cavities in glass and glass-containing ceramics at elevated temperatures was studied. The systems studied were: Coming 7056 alkali borosilicate glass, soda-lime glass (microscope slides), a commercially available 96% Al{sub 2}O{sub 3}with {approx}5--10% intergranular glass, 96% Al{sub 2}O{sub 3} bonded to sapphire, and a model sapphire/glass/sapphire system fabricated by diffusion bonding etched and unetched pieces of sapphire onto which 30--50 nm of SiO{sub 2} had been sputter deposited. These systems span a broad range of glass contents, and permit observation of healing behavior with varying glass content. The results were compared with analytical models and results of similar studies in completely crystalline systems.

This dissertation consists of two closely related parts: theory development and coding of correlation effects in a model potential for solvation, and study of solvent effects on chemical reactions and processes. The effective fragment potential (EFP) method has been re-parameterized, using density functional theory (DFT), more specifically, the B3LYP functional. The DFT based EFP method includes short-range correlation effects; hence it is a first step in incorporating the treatment of correlation in the EFP solvation model. In addition, the gradient of the charge penetration term in the EFP model was derived and coded. The new method has been implemented in the electronic structure code GAMESS and is in use. Formulas for the dynamic dipole polarizability, C{sub 6} dispersion coefficient and dispersion energy were derived and coded as a part of a treatment of the dispersion interactions in the general solvation model, EFP2. Preliminary results are in good agreement with experimental and other theoretical data. The DFT based EFP (EFP1/DFT) method was used in the study of microsolvation effects on the S{sub N}2 substitution reaction, between chloride and methyl bromide. Changes in the central barrier, for several lowest lying isomers of the systems with one, two, three and four waters, were …

None

Arsenic in drinking water is a major public health problem threatening the lives of over 140 million people worldwide. In Bangladesh alone, up to 57 million people drink arsenic-laden water from shallow wells. ElectroChemical Arsenic Remediation(ECAR) overcomes many of the obstacles that plague current technologies and can be used affordably and on a small-scale, allowing for rapid dissemination into Bangladesh to address this arsenic crisis. In this work, ECAR was shown to effectively reduce 550 - 580 mu g=L arsenic (including both As[III]and As[V]in a 1:1 ratio) to below the WHO recommended maximum limit of 10 mu g=L in synthetic Bangladesh groundwater containing relevant concentrations of competitive ions such as phosphate, silicate, and bicarbonate. Arsenic removal capacity was found to be approximately constant within certain ranges of current density, but was found to change substantially between ranges. In order of decreasing arsenic removal capacity, the pattern was: 0.02 mA=cm2> 0.07 mA=cm2> 0.30 - 1.1 mA=cm2> 5.0 - 100 mA=cm2. Current processing time was found to effect arsenic removal capacity independent of either charge density or current density. Electrode polarization studies showed no passivation of the electrode in the tested range (up to current density 10 mA=cm2) and ruled out oxygen …

A measurement of the top quark mass in p{bar p} collisions at {radical}s = 1.96 TeV is presented. The analysis uses a template method, in which the overconstrained kinematics of the Lepton+Jets channel of the t{bar t} system are used to measure a single quantity, the reconstructed top quark mass, that is strongly correlated with the true top quark mass. in addition, the dijet mass of the hadronically decaying W boson is used to constrain in situ the uncertain jet energy scale in the CDF detector. Two-dimensional probability density functions are derived using a kernel density estimate-based machinery. Using 1.9 fb{sup -1} of data, the top quark mass is measured to be 171.8{sub -1.9}{sup +1.9}(stat.) {+-} 1.0(syst.)GeV/c{sup 2}.

None

None

None

In this thesis, the author argues that the supersymmetric Standard Model, while avoiding the fine tuning in electroweak symmetry breaking, requires unnaturalness/fine tuning in some (other) sector of the theory. For example, Baryon and Lepton number violating operators are allowed which lead to proton decay and flavor changing neutral currents. He studies some of the constraints from the latter in this thesis. He has to impose an R-parity for the theory to be both natural and viable. In the absence of flavor symmetries, the supersymmetry breaking masses for the squarks and sleptons lead to too large flavor changing neutral currents. He shows that two of the solutions to this problem, gauge mediation of supersymmetry breaking and making the scalars of the first two generations heavier than a few TeV, reintroduce fine tuning in electroweak symmetry breaking. He also constructs a model of low energy gauge mediation with a non-minimal messenger sector which improves the fine tuning and also generates required Higgs mass terms. He shows that this model can be derived from a Grand Unified Theory despite the non-minimal spectrum.

None

This work is a theoretical investigation on the physical properties of semiconductor-based two-dimensional photonic crystals, in particular for what concerns systems embedded in planar dielectric waveguides (GaAs/AlGaAs, GaInAsP/InP heterostructures, and self-standing membranes) or based on macro-porous silicon. The photonic-band structure of photonic crystals and photonic-crystal slabs is numerically computed and the associated light-line problem is discussed, which points to the issue of intrinsic out-of-lane diffraction losses for the photonic bands lying above the light line. The photonic states are then classified by the group theory formalism: each mode is related to an irreducible representation of the corresponding small point group. The optical properties are investigated by means of the scattering matrix method, which numerically implements a variable-angle-reflectance experiment; comparison with experiments is also provided. The analysis of surface reflectance proves the existence of selection rules for coupling an external wave to a certain photonic mode. Such rules can be directly derived from symmetry considerations. Lastly, the control of wave propagation in weak-index contrast photonic-crystal slabs is tackled in view of designing building blocks for photonic integrated circuits. The proposed designs are found to comply with the major requirements of low-loss propagation, high and single-mode transmission. These notions are then collected …

The FOCUS experiment is designed to investigate charm particle decays. These charm particles are produced by the interaction of a photon beam with an average energy of 175 GeV on a BeO target and travel an average of few millimeters before decaying in the spectrometer. By reconstructing the daughters from the decay, we can infer properties of the charm particles. Semileptonic decays have been used to measure many CKM matrix elements. These decays are interesting due to the simplicity of their theoretical description but they are experimentally challenging due to the fact that a neutrino is not detected. Analysis of semileptonic decays in the charm sector are of great interest because they provide an excellent environment to test and to calibrate theoretical calculation that can be implemented in the determination of poorly known matrix elements such as V{sub ub}. In this thesis we report an analysis of the decays D{sup 0} {yields} {pi}{sup -}{mu}{sup +}{nu} and D{sup 0} {yields} K{sup -} {mu}{sup +}{nu}. We measure the relative branching ratio as well as the ratio of the form factors f{sub +}{sup {pi}}(0)/f{sub +}{sup K}(0). Using a weighting technique, we further report a parametric analysis of the q{sup 2} dependence for both …

None

We calculate the exclusion region in the parameter space of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations of the LSND type using a combined fit to the reconstructed energy distributions of neutrino candidate samples from the MiniBooNE data obtained with two different particle identification methods. The two {nu}{sub e} candidate samples are included together with a high statistics sample of {nu}{sub {mu}} events in the definition of a {chi}{sup 2} statistic which includes the correlations between the energy intervals of all three samples and handles the event overlap between the {nu}{sub e} samples. The {nu}{sub {mu}} sample is introduced to constrain the effect of systematic uncertainties. This analysis increases the exclusion limit in the region {Delta}m{sup 2} {approx}< 1eV{sup 2} when compared with the result previously published by the collaboration, which used a different technique.

The nuclear radiations of nuclides: U{sup 233}, Pu{sup 239}, Bk{sup 243}, Bk{sup 244}, Bk{sup 245}, Bk{sup 246}, Bk{sup 249}, Cf{sup 249}, and Fm{sup 255} were investigated with high-resolution spectrometers. The {alpha}-particle spectra of all nuclides except Bk{sup 249} were measured with 6 mm diameter surface-barrier detectors. Bk{sup 249} {alpha}-particles were analyzed with a double-focusing magnetic spectrograph. The {gamma}-singles were examined with the recently developed Ge(Li) and Si(Li) detectors coupled with very-low noise 'internal FET' preamplifiers. Weak alpha groups were observed in coincidence with {gamma}-rays, detected with a NaI(Tl) scintillation spectrometer. To improve the over-all coincidence efficiency a new coincidence apparatus was designed and built. This instrument consisted of a cooled 4.5 cm diameter semiconductor detector for {alpha}-particle detection and a 3 cm diameter by 2.7 cm long Ge(Li) detector for {gamma}-ray analysis. The Ge(Li) detector could also be replaced with a NaI(Tl) detector. Cf{sup 249} conversion electrons were measured with a cooled Si(Li) detector coupled with an internal FET preamplifier. On the basis of the present work and previous information, energy-level diagrams of the daughter nuclei have been constructed. The levels have been grouped into rotational bands built on Nilsson single-particle states. Because of identification of several rotational members of …

This dissertation reports on a study of search for an orbitally excited state of charmed baryons {Sigma}{sub c}{sup 0}(2800) and {Sigma}{sub c}{sup ++}(2800). They measure the widths, momentum spectrum and production cross-section for these states decaying into a {Lambda}{sub c}{sup +} and a charged {pi}. The analysis uses 230 fb{sup -1} of data collected at BABAR detector operating at PEP-II collider at Stanford Linear Accelerator Center. The data is collected in the region of {Upsilon}(4S) an {approx} 40 MeV below the resonance. {Lambda}{sub c}{sup +} baryon is reconstructed in the decay mode pK{sup -}{pi}{sup +}. The {Sigma}{sub c}(2800) baryon production at continuum is observed to be quite significant for x{sub p} > 0.7, where x{sub p} = p/{radical}E{sup 2}+M{sup 2} is the scaled momentum and varies from 0.0 to 1.0. The momentum spectrum is measured by considering the corrected yield for momentum bins above x{sub p} > 0.5 and can be parameterized very well by a Peterson function, given by: dN/dx{sub p} {proportional_to} 1/x{sub p}(1 - 1/x{sub p} - {epsilon}/1-x{sub p}){sup 2}. The values for the peterson parameter {epsilon}, are found to be 0.050 {+-} 0.010 for {Sigma}{sub c}{sup 0}(2800) and 0.057 {+-} 0.012 for {Sigma}{sub c}{sup ++}(2800). They use …

The family of R{sub 5}Si{sub x}Ge{sub 4-x} alloys demonstrates a variety of unique physical phenomena related to magneto-structural transitions associated with reversible breaking and reforming of specific bonds that can be controlled by numerous external parameters such as chemical composition, magnetic field, temperature, and pressure. Therefore, R{sub 5}Si{sub x}Ge{sub 4-x} systems have been extensively studied to uncover the mechanism of the extraordinary magneto-responsive properties including the giant magnetoresistance (GMR) and colossal magnetostriction, as well as giant magnetocaloric effect (GMCE). Until now, more than a half of possible R{sub 5}Si{sub x}Ge{sub 4-x} pseudobinary systems have been completely or partially investigated with respect to their crystallography and phase relationships (R = La, Pr, Nd, Gd, Tb, Dy, Er, Lu, Y). Still, there are other R{sub 5}Si{sub x}Ge{sub 4-x} systems (R = Ce, Sm, Ho, Tm, and Yb) that are not studied yet. Here, we report on phase relationships and structural, magnetic, and thermodynamic properties in the Yb{sub 5}Si{sub x}Ge{sub 4-x} and Sm{sub 5}Si{sub x}Ge{sub 4-x} pseudobinary systems, which may exhibit mixed valence states. The crystallography, phase relationships, and physical properties of Yb{sub 5}Si{sub x}Ge{sub 4-x} alloys with 0 {le} x {le} 4 have been examined by using single crystal and powder x-ray …

This dissertation describes a measurement of the rate of associated production of the W boson with the charm jet in the proton and anti-proton collisions at the center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. The measurement has direct sensitivity to the strange quark content inside the proton. A direct measurement of the momentum distribution of the strange quark inside the proton is essential for a reliable calculation of new physics signal as well as the background processes at the collider experiments. The identification of events containing a W boson and a charm jet is based on the leptonic decays of the W boson together with a tagging technique for the charm jet identification based on the semileptonic decay of the charm quark into the muon. The charm jet recoiling against the W boson must have a minimum transverse momentum of 20 GeV and an absolute value of pseudorapidity less than 2.5. This measurement utilizes the data collected by the D0 detector at the Fermilab Collider. The measured rate of the charm jet production in association with the W boson in the inclusive jet production with the W boson is 0.074 {+-} 0.023, which is in agreement with …

This thesis is concerned with both the application and the extension of quantum chemical methods. Each chapter of the thesis represents a paper that has been published in or will be submitted to a scientific journal. The first three chapters of this thesis describe contributions made to chemistry through the use of quantum chemical methods, while the final two chapters illustrate the development of new methods. Chapter 2 and Chapter 3 characterize a study of the electronic structure and magnetic properties of homodinuclear titanium(III) complexes, in order to determine trends related to their potential use as molecular magnets. Chapter 2 focuses on hydride and halide bridging and terminal ligands, while Chapter 3 explores bridging ligands from other groups in the periodic table. Chapter 4 portrays a study of the solvation of glycine. Microsolvation and continuum solvation approaches are investigated in order to study the structures of small glycine-water clusters and determine the energy difference between the zwitterionic and nonionized forms of glycine, the simplest amino acid. Chapters 5 and 6 describe the implementation of analytic gradients, which are required for efficient molecular geometry optimizations, for two open-shell second-order perturbation theory methods. Chapter 5 discusses gradients for unrestricted Moeller-Plesset perturbation theory, …