Fusion neutrons from high energy density plasmas generated by pulsed laser irradiation of nanoscale atomic clusters have been explored in recent experiments at the University of Texas at Austin. A sufficiently strong (~200 T) magnetic field is expected to produce a magnetized, high temperature (10 keV) plasma with beta [approximately equal to] 1. Such a field along the laser axis may confine the plasma’s radial expansion, thus increasing fusion yield. As part of a multi-stage project to implement this experiment, a scaled (~40 T, ~500 KA) version of the final 200 T, 2.2 MA pulsed power device has been designed and built by Sandia National Laboratories and is now at UT-Austin. This apparatus, named MegaGauss, is meant to serve as a preparation tool for the 200 T system; as such, its current pulse was recorded for analysis, and is compared to a theoretical model to verify its response parameters (e.g. peak current, time to peak). Techniques and results of this comparison are discussed, followed by explanations of basic construction of the 40 T device and current sensing instrumentation. Discussion of MegaGauss is completed with a survey of notable failure modes, and a description of the often severe effects the miniature field-generating Helmholtz coil experiences due to the current pulse and magnetic field. Finally, a novel data archive scheme, structured around the familiar MDSplus archive system, is implemented in Labview and integrated into the main pulsed power control program. Specifically, methods for linking MDSplus’s robust functionality with Labview’s intuitive development environment are realized by means of a specialized software bridge between the two. These methods are used in software that allows MDSplus archives to be written and read exclusively through Labview. / text

Made available in DSpace on 2015-05-14T12:13:59Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 283471 bytes, checksum: 3c03d229984755f09c77c7e98c3f465e (MD5) Previous issue date: 2011-06-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we present a quantum description of a mesoscopic RLC circuit without source. For this purpose, we model this system for that of a damped harmonic oscillator which is described by the Caldirola-Kanai Hamiltonian. Then, with the aid of the quantum invariant method we solve the Schrödinger equation associated with this Hamiltonian and write the corresponding wave functions in terms of a particular solution of the Milne-Pinney equation. We also construct coherent states for the RLC quantized, and evaluate the quantum fluctuations of the charge and the magnetic flux, as well as the corresponding product of uncertainty. / Nesta dissertação, apresentamos uma descrição quântica de um circuito RLC mesoscópico sem fonte. Com esta finalidade, modelamos este sistema para aquele de um oscilador harmônico amortecido, que é descrito pelo Hamiltoniano de Caldirola-Kanai. Então, com a ajuda do método de invariantes quânticos, resolvemos a equação de Schrödinger para este Hamiltoniano e escrevemos as funções de onda correspondentes em termos da solução particular da equação de Milne-Pinney. Também construímos estados coerentes para o circuito RLC quantizado, e calculamos as flutuações quânticas da carga e do fluxo magnético, bem como o produto de incerteza correspondente.

This Master’s dissertation focuses on engineering artificial nanostructures, namely, arrays of metamolecules on a substrate (metasurfaces), with the goal to achieve the desired linear and nonlinear optical responses. Specifically, a simple analytical model capable of predicting optical nonlinearity of an individual metamolecule has been developed. The model allows one to estimate the nonlinear optical response (linear polarizability and nonlinear hyperpolarizabilities) of a metamolecule based on the knowledge of its shape, dimensions, and material. In addition, a new experimental approach to measure hyperpolarizability has also been investigated. As another research effort, a 2D plasmonic metasurface with the collective behaviour of the metamolecules known as hybrid plasmonic-Fabry-Perot cavity and surface lattice resonances was designed, fabricated and optically characterized. We experimentally discovered a novel way of coupling the microcavity resonances and the diffraction orders of the plasmonic metamolecule arrays with the low-quality plasmon resonance to generate multiple sharp resonances with the higher quality factors. Finally, we experimentally observed and demonstrated a record ultra-high-Q surface lattice resonance from a plasmonic metasurface. These novel results can be used to render highly efficient nonlinear optical responses relying on high optical field localization, and can serve as the stepping stone towards achieving practical artificial nanophotonic devices with tailored linear and nonlinear optical responses.

Made available in DSpace on 2015-05-14T12:14:17Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 686892 bytes, checksum: cec59fce2ac377aef923c62e1cac0207 (MD5) Previous issue date: 2014-06-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / We present an alternative quantum treatment for a generalized mesoscopic RLC circuit with time-dependent resistance, inductance and capacitance. Taking advantage of the Lewis and Riesenfeld and quadratic invariants we obtain exact nonstationary Schrödinger states for this electromagnetic oscillation system. Afterwards, we construct coherent states for the quantized RLC circuit and employ them to investigate some of the system s quantum properties, such as quantum fluctuations of the charge and the magnetic flux and the corresponding uncertainty product. In addition, we derive the geometric, dynamical and Berry phases for this nonstationary mesoscopic circuit. Finally we evaluate the dynamical and Berry phases for three special circuits. Surprisingly, we find identical expressions for the dynamical phase and the same formulae for the Berry s phase. / Apresentamos um tratamento quântico alternativo para um circuito RLC mesoscópico generalizado com resistência, indutância e capacitância dependentes do tempo. Usando o método de invariantes quânticos de Lewis e Riesenfeld e invariantes quadráticos, obtemos os estados de Scrhödinger não-estacionários para este circuito com oscilação eletromagnética. Em seguida, construímos os estados coerentes para o circuito RLC quantizado e os empregamos para investigar algumas das propriedades quânticas do sistema, tais como flutuações quânticas da carga, do fluxo magnético e o produto incerteza correspondente. Além disso, obtemos as fases geométricas, dinâmicas e de Berry para este circuito mesoscópico não estacionário. Finalmente, calculamos as fases dinâmica e de Berry para três casos particulares. Surpreendentemente, encontramos expressões idênticas para a fase dinâmica, e as mesmas expressões para a fase da Berry.

This thesis deals with design of electronic laboratory model for teaching mechatronic subjects. The main part of the model consists of a RLC-circuit embedded in PCB. Other parts of PCB and data acquisition card mediate communication with Matlab environment. In the thesis the progress of design process, simulation, manufacture and model testing is described. The results are functioning educational model and several educational tasks, for which the solution are presented.