Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 176-180).

The dark matter search CRESST-II completed its most recent run, Run 32, in 2011. Compared to previous runs, the quantity of data taken in this run increased , significantly. In this work, Oxrop, analysis software in use within the CRESST collaboration, is upgraded to analyse this new data. At the same time, Oxrop's internal structure is improved so that it can now handle data from detectors across different experiments consistently. This upgrade was performed with a view to developing Oxrop's candidacy for use with EURECA, a future dark matter experiment. Oxrop is then used to model CRESST-II data .. First, light detector response to scintillation light produced in y interactions in CRESST -Il' s target crystals is examined. A factor influencing detector efficiency is the time constant of scintillation light production, and this light detector examination is performed with a view to extracting the scintillation time constants of the target crystals. A simple model of light detector response of one exponential rise and two exponential decay times is initially considered. It is shown that this simple model does not closely match the light detector response to y interactions in the crystal scintillator. Empirical extensions to this expected model are then made, allowing for additional decay times. These extensions allow the light detector response to crystal scintillator interactions to be well modelled, and allow estimates of the millikelvin y scintillation time of Ca W04 and Zn W04. This model is then also applied to X-ray interactions directly in the light detectors. It is seen that, even with these model extensions, interactions directly in the light detector still show significant tension with the applied model. This implies that direct calibration of light detectors with X-rays is not possible without a further understanding of light detector response, or that future direct calibrations should be done with optical photons. Position dependent effects in Run 32 calibration data are then studied. A phenomenon that has previously been considered as unrelated to position dependence, the anti-correlation effect between phonon and light detector signals, is shown to exhibit a position dependent effect in at least one lightjphonon detector pair under study. Additionally, the collection efficiency of the light detector is shown to be related to the mean interaction position. Collection efficiency is found to reduce when mean interaction position is close to the cylindrical surfaces of CRESST's Ca W04 target crystals. The magnitude of the difference in light collection: efficiency between surface and bulk interactions is also seen to be correlated with high energy light detector resolution. The WIMP-nucleon cross section limits resulting from the CRESST-II commissioning run (2007) are also reanalysed in this work. The original analysis of the commissioning run accounted only for tungsten recoils in the Ca W04 crystals used in CRESST - II. Here, interactions from calcium and oxygen nuclei are also accounted for. The resulting WIMP-nucleon cross section limits were improved at light WIMP masses -0(10 GeV j c2). These limits show a mild tension with a recent dark matter analysis of Run 32, particularly for WIMP masses below 10 GeV j c2. Possible causes of this tension are discussed

No description available.

Thesis (M.E.E.)--University of Delaware, 2006. / Principal faculty advisor: Fouad Kiamilev, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 85-89). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 85-89). Also available on the Internet.

Orientador: Luiz Otavio Saraiva Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T21:02:18Z (GMT). No. of bitstreams: 1 Oliveira_LuizClaudioMarangonide_D.pdf: 9710529 bytes, checksum: 4fc22426f2b4d1d845715c4742df71a2 (MD5) Previous issue date: 2006 / Resumo: Scanners são dispositivos que defletem um feixe luminoso e transfonnam um feixe puntual em uma linha de varredura, com amplitude e freqüência controladas. Diversos equipamentos utilizam este padrão luminoso para codificar ou decodificar infonnações, exemplos mais comuns são os leitores de código de barras de bancada, utilizados em supennercados, e as impressoras laser. V ários fenômenos podem ser empregados para defletir um feixe luminoso. Neste trabalho, os scanners utilizam o princípio da reflexão da luz por um espelho em movimento hannônico e ressonante sob ação de forças de origem eletromagnética. Tais forças são geradas pela interação de correntes induzi das na annadura, com o campo magnético produzido por ímãs pennanentes. A principal vantagem deste tipo de scanner é a ausência de conexões elétricas entre as partes móveis e fixas do dispositivo, o que simplifica o processo de fabricação e o toma mais robusto e menos suceptível a falhas. Parte dos scanners similares existentes atualmente são dispositivos eletro-mecânicos complexos, fabricados em série. Trabalhos anteriores demonstraram a viabilidade da geometria planar e da utilização de processos de fabricação em lotes, derivados da microeletrônica, neste tipo de scanner. Os protótipos fabricados, embora funcionais, apresentaram consumo de potência acima da média para este tipo de dispositivo, o que demonstrava a necessidade de melhorias em seu projeto. O processo de fabricação, embora confiável, foi desenvolvido com materiais e métodos baseados no Silício e originários da microeletrônica, o que dificultava sua implantação em indústrias em território nacional. Neste trabalho, foram pr9postos aprimoramentos à tecnologia dos scanners ressonantes planares atuados por indução para tomar seu desempenho compatível com o d~ dispositivos similares, e também para viabilizar sua fabricação utilizando materiais e métodos disponíveis no país. Uma metodologia de projeto, em conjunto com uma série de contribuições ao modelo, foi proposta e avaliada. Para viabilizar a fabricação propôs-se a utilização do Bronze-fosforoso, como material estrutural, e a utilização de foto-fabricação, como processo de fabricação. As contribuições propostas neste trabalho possibilitaram a redução do consumo de potência de 2, 2 W para cerca de 5 m W por grau óptico, e o aumento da freqüência de operação do circuito de cerca de 1 kHz para 4 kHz, com um ângulo de deflexão óptico típico de 20° pico-a-pico, parâmetros compatíveis com os de dispositivos similares, mas mecanicamente mais complexos e fabricados por processo serial / Abstract: Scanners are devices that deftects a light beam and converts a spot light in a well controlled amplitude and frequency scan line. Several applications uses the generated pattem to code or decode data, common examples ar,e barcode readers, and laser printers. A light beam can be deftected by different means. In this work, the scanner deftects the light by reftection in a moving mirror, in a resonant and harmonic movement, subjected to forces of electromagnetic nature. Such forces are generated by the interaction between an induced current in the armature, and a magnetic field, generated by permanent magnets. The main advantage of this kind of scanner is the absence of electrical connections between the mobile, and fixed parts of the device, that simplifies the fabrication process, and make its more reliable and less fault susceptible. Part of the similar devices available today are complex eIectro-mechanical devices, manufactured by serial processo Earlier works established that the planar geometry, and the use of batch fabrication process, derived from microelectronics, are feasible with this kind of device. A1though functional, the earlier prototypes presented a high power consumption, that shown the demand for an improved designo The Silicon-based fabrication process adopted makes the use of materiaIs and methods that are not readily accessible to the Brazilian industry. In this work improvements were proposed to the induction actuated planar resonant scanners technology. The goal was to make its performance compatible with the performance of similar devices, and to enable its fabrication using materiaIs and methods available to the Brazilian industry. A design m~thodology, and a set of model contributions were proposed and validated. The use of Phosphor-bronze, as structural material, and the photqfabrication process, as the machining method, were proposed as an option to the Silicon-based fabrication method. The contributions ofthis work had enabled the reduction ofthe power consumptlon from 2,2 W to about 5 m W per optical degree, and an increase in the working frequency from 1 kHz to 4kHz, with a optical deftection angle of about 20° peak-to-peak. Such parameters are fully compatible with similar devices, mechanically more complexes and manufactured by serial processes / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica