Indiana University-Purdue University Indianapolis (IUPUI) / In this work we have designed and simulated a thermal bi-directional integrated circuit mass flow sensor. The approach used here was an extension to the gas flow model given by Mayer and Lechner. The design features high precision response received from analog integrated circuits. A computational fluid dynamic (CFD) model was designed for simulations with air and water Using COMSOL Multiphysics. Established mathematical models for the heat flow equations including CFD parameters were used within COMSOL simulation(COMSOL Multiphysics, Sweden). Heat pulses of 55 °C for a period of nearly 120 seconds and 50% duty cycles were applied as thermal sources to the flowstream. The boundary conditions of the heat equations at the solid (heating element) fluid interface were set up in the software for the thermal response. The hardware design included one heating element and two sensing elements to detect the bi-directional mass flow. Platinum sensors were used due to their linear characteristics within 0 ºC to 100 ºC range, and their high temperature coefficient(0.00385 Ω/Ω/ºC). Polyimide thinfilm heater was used as the heating element due to its high throughput and good thermal efficiency. Two bridge circuits were used to sense the temperature distribution in the vicinity of the sensing elements. Three high precision instrumentation low power amplifiers with offset voltage ~2.5μV (50μV max) were used for bridge signal amplification and the difference circuit. The difference circuit was used to indicate the flow direction. A LM555 timer chip was utilized to provide the heat pulse period. Simulation and experimental measurements for heat pulses with different amplitude (temperature) were in good agreement. Also, the sensitivity of the flow sensor was observed to remain unaffected with the change in the duty cycle of the heat operation mode.

The Standard Model of particle physics constitutes the most accurate and comprehensive known description of the fundamental building blocks of the universe. However, overwhelming evidence suggests that the theory is incomplete and that new physics may be hiding at the TeV-scale. The Large Hadron Collider (LHC) at CERN probes these high-energy scales, opening a potential gateway to access physics beyond the Standard Model (BSM). Long-lived particles (LLPs) arise in many promising BSM theories, but they remain weakly constrained at the LHC. This thesis presents a novel search for displaced and delayed diphoton and dielectron vertices originating from the decay of a neutral LLP. The analysis uses the full LHC Run 2 dataset of pp collisions at a center-of-mass energy of √s = 13 TeV recorded by the ATLAS detector, corresponding to an integrated luminosity of 139 fb-1. The search harnesses the capabilities of the ATLAS Liquid Argon calorimeter to precisely measure the displacement and delay of the final state electromagnetic objects. The results are interpreted in a gauge-mediated supersymmetry breaking model that features the pair-production of LLPs, with each LLP subsequently decaying into either a Higgs boson or a Z boson. Since no significant excess is observed above the background expectation, the results are used to set upper limits on the cross section of LLP pair-production for signals with an LLP mass between 100 and 725 GeV and lifetime between 0.25 ns and 1 μs. A model-independent limit is also set on the production of pairs of photons or electrons with a significantly delayed arrival at the calorimeter.

"Material property estimation method is developed with 1-D heat conduction model and bounding exercise for Fire Dynamics Simulator (FDS) analysis. The purpose of this study is to develop an unsophisticated tool to convert small scale cone calorimeter data into input data that can be used in computational fluid dynamics (CFD) models to predict flame spread. Specific interests of input data for FDS in this study include thermal conductivity, specific heat, pre exponential factor, activation energy, heat of vaporization. The tool consists of two objects; 1-D model and bounding exercise. Main structure of the model is based on one of the thermal boundary conditions in the FDS, named as “Pyrolysis Model, Thermally-Thick Solid”, in which pyrolysis flux occurs on the surface of the object under radiant heat flux. This boundary condition is adopted because it has the best characteristics in the dynamics of modeling which are subject to our interests. The structure of the model is simple and concise. For engineering point of view, a practical model ought to have such simplicity that saves time and effort. Pyrolysis model in FDS meets this requirement. It is also a part of reason that this study is to develop a computational model which converts a set of data from the cone calorimeter test to a set of input data for FDS. A pyrolysis term on a surface of an object in this boundary condition will be playing an important role regarding a surface temperature and a mass loss rate of the object. Bounding exercise is introduced to guide proper outcome out of the modeling. Prediction of the material properties from the simulation is confirmed by the experimental data in terms of surface temperature history and mass loss rate under the bounding exercise procedure. For the cone calorimeter, thirteen different materials are tested. Test materials vary with their material composition such as thermoplastics, fiber reinforced plastics (FRP), and a wood. Throughout the modeling fed by a set of the cone calorimeter test data, estimated material properties are provided. So called “Bounding Exercise” is introduced here to draw the estimated material properties. Bounding exercise is a tool in order to guide the material property estimation procedure. Three sets of properties (Upper, Standard and Lower) are derived from the boundary exercise as recommended material properties. From the modeling results, PMMA shows the best agreement regarding the estimated material properties compared with already known results from the references. Wood indicates, however, somewhat different results, in which the mass loss rate takes a peak around the ignition and decreases sharply. This burning behavior can not be predicted using the “Pyrolysis Model”. The model in this study does not account so called “Charring Behavior” that a charring layer toward a surface or difference between a charred density in a charring layer and a normal density in a virgin layer of a wood. These factors result in a discrepancy of the estimated material properties with the reference data. Unlike PMMA and wood, FRP materials show a unique ignition characteristic. Mass loss rate history from some FRP materials indicate more a thermoplastic burning behavior and other materials tend to char. In addition there are few known material property data for theses materials and it is difficult to verify the results from this study with pre-existing data. Some plastic samples also indicate difficulties of the modeling. Because some samples melt and disfigure during the test, one dimensional heat transfer boundary condition is no longer applicable. Each bounding exercise results are fully examined and analyze in Chapter 6. Some of limitations contain model’s structural limitation, in which the model is too simple for certain cases, as well as limitations of bounding exercise. Finally, recommendations are made for future work including upgraded model accountable for the pyrolysis of charring material and FRP materials, data comparison with FDS results, and improved bounding exercise method."

Compartment fire scenarios are of great interest due to the large loss of life and property that occurs annually in such fires. Due to the current move towards performance-based building code standards and the increasing acceptance by the regulatory system of model results, there is a growing need for detailed compartment fire data to demonstrate the accuracy of such engineering tools as they are used to ascertain performance. A series of carefully designed full-scale room/corner tests on two vinyl ester resin composite systems have been conducted in a heavily instrumented compartment to provide compartment fire data for the calibration of engineering tools. The two composite systems were chosen based on their thermal behavior. A nominally thermally-thick glass-reinforced plastic (GRP) skin was desirable, as many analytical formulations have been developed using semi-infinite assumptions. A "thermally-thin" skin panel typical of that used in fast ferry construction, consisting of a GRP skin over a balsa core, was also tested. The test protocol used throughout the room/corner experiments was a modification of the ISO 9705 standard where the HRR of the ignition fire was varied according to the Critical Ignition Source Strength concept. To date, there has been little work done where heat fluxes from compartment fires have been measured. Therefore, one of the key data components developed in this series of tests are heat flux measurements from thin skin calorimeters. A total of twenty-five thin skin calorimeters, constructed of Inconel plates, were located throughout the room: the spatial distribution of net and incident heat fluxes within compartment for both pre- and post-flashover conditions have been determined. Additionally, rakes of bare-bead thermocouples were placed in the vent and the corner of the room coincident with the thin skin calorimeter arrays. A third rake was placed in the center of the room. The thermocouple arrays provide data regarding layer temperatures and interface heights as well as a limited determination of temperature spatial distribution within the compartment. The thermocouple rakes also permit calculation of pressure gradients across and mass flows through the vent, thus providing information regarding wall lining fire entrainment rates, of use in corner fire algorithm validations and for globally evaluating the accuracy of CFD codes. Bench-scale cone calorimeter (ASTM E1354, ISO 5660) tests have been carried out on the two composite systems to gather material fire properties necessary as model inputs for fire spread algorithms. The present study developed material properties including heat release rate, species production, and ignition data for the two composite systems. Included are uncertainty bands that account for calculation and instrument uncertainty.

L'objectif de ce travail de thèse est de démontrer le potentiel des calorimètres métalliques magnétiques pour la spectrométrie bêta via une mesure du spectre du 63-Ni. Ce nucléide fait partie des émetteurs bêta pour lesquels la théorie est connue et les calculs crédibles. Nous proposons une méthode d'observation expérimentale du spectre, à basse énergie surtout, permettant de valider les calculs théoriques.Un traitement des données spécifique à l'établissement d'un spectre continu a été établi et optimisé, prenant en compte les paramètres d'une mesure cryogénique avec un calorimètre métallique magnétique et les exigences de la spectrométrie bêta.Deux types de sources ont été réalisés, un dépôt sous forme de sel de nickel à partir d'une goutte séchée de solution de NiCl2 et un dépôt métallique de nickel issu d'une électrodéposition. Les sources électrodéposées se sont révélées être le type de source adéquate pour la spectrométrie du 63-Ni.Les performances des calorimètres métalliques magnétiques, parmi lesquelles le fort rendement de détection ou le faible seuil en énergie, permettent d'obtenir des résultats suffisamment précis pour la validation expérimentale des calculs théoriques. / The aim of this thesis is to demonstrate the potential of metallic magnetic calorimeters for beta spectrometry by measuring the spectrum of 63-Ni. This nuclide is one of the beta emitters for which theory is well-known and calculation reliable. We propose a method for experimental observation, especially at low energies, which allows to validate the theoretical calculation.A dedicated data analysis has been established and optimized. It takes into account the parameters of a cryogenic measurement and also the specific requirements of beta spectrometryTwo types of sources have been realized, a deposit of nickel salt from a dried drop of a solution of NiCl2 and a metallic electroplated source of Ni. The electroplated sources turn out to be the appropriate type of source for 63-Ni spectrometry.The performances of metallic magnetic calorimeters, such as high detection efficiency and low energy threshold, lead to results precise enough to validate experimentally the theory.

This dissertation investigates CsI(Tl) pulse shape discrimination (PSD) as a novel experimental technique to improve challenging areas of particle identification at high energy $e^+ e^-$ colliders using CsI(Tl) calorimeters. In this work CsI(Tl) PSD is implemented and studied at the Belle II experiment operating at the SuperKEKB $e^+ e^-$ collider, representing the first application of CsI(Tl) PSD at a $B$ factory experiment. Results are presented from Belle II as well as a testbeam completed at the TRIUMF proton and neutron irradiation facility. From the analysis of the testbeam data, energy deposits from highly ionizing particles are shown to produce a CsI(Tl) scintillation component with decay time of $630\pm10$ ns, referred to as the hadron scintillation component, and not present in energy deposits from electromagnetic showers or minimum ionizing particles. By measuring the fraction of hadron scintillation emission relative to the total scintillation emission, a new method for CsI(Tl) pulse shape characterization is developed and implemented at the Belle II experiment's electromagnetic calorimeter, constructed from 8736 CsI(Tl) crystals. A theoretical model is formulated to allow for simulations of the particle dependent CsI(Tl) scintillation response. This model is incorporated into GEANT4 simulations of the testbeam apparatus and the Belle II detector, allowing for accurate simulations of the observed particle dependent scintillation response of CsI(Tl). With $e^\pm$, $\mu^\pm$, $\pi^\pm$, $K^\pm$ and $p/\bar{p}$ control samples selected from Belle II collision data the performance of this new simulation technique is evaluated. In addition the performance of hadronic interaction modelling by GEANT4 particle interactions in matter simulation libraries is studied and using PSD potential sources of data vs. simulation disagreement are identified. A PSD-based multivariate classifier trained for $K_L^0$ vs. photon identification is also presented. With $K_L^0$ and photon control samples selected from Belle II collision data, pulse shape discrimination is shown to allow for high efficiency $K_L^0$ identification with low photon backgrounds as well as improved $\pi^0$ identification compared to shower-shape based methods. / Graduate

Made available in DSpace on 2014-10-09T12:42:14Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:44Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:42:14Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:44Z (GMT). No. of bitstreams: 0 / A calorimetria vem a ser uma importante técnica para análise dos processos de polimerização. Dado os benefícios que proporciona seu uso não deve estar limitado somente a grandes empresas, mas também nas micro e pequenas empresas, apoiando-as nas melhorias de seus processos e produtos, motivo este que norteia o desenvolvimento do presente estudo. A validação do sistema proposto baseou-se em comparar seu desempenho frente a um calorímetro tradicional, visando identificar sua capacidade de fornecer informações compatíveis, a um grau de confiança adequado, mesmo com as diferenças existentes. Realizou-se então um ANOVA, que permitiu identificar a existência de outras diferenças importantes entre os sistemas. Porém mesmo frente as diferenças, os resultados quanto à entalpia de reação obtidos em ambos os equipamentos, são considerados estatisticamente similares. As diferenças existentes somente impactaram a variável tempo de pico de reação. Desta forma, foi possível confirmar a capacidade do equipamento proposto em prover resultados confiáveis quando mantidas as mesmas condições de ensaio, porém a um menor custo. No caso de se respeitar as diferenças entre os equipamentos quando da realização dos testes, torna-se possível obter uma eficiência global em torno de 61,21%, quanto a ensaios de polimerização por iniciação térmica. No caso de ensaios envolvendo mecanismos de oxi-redução, pode-se aqui obter um percentual de 40,82%. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

A ce jour la détermination de l’angle γ du Triangle d’Unitarité de la matrice de Cabibbo-Kabayashi-Maskawa est statistiquement limitée par la rareté des transitions b→ u. La précision obtenue en combinant les résultats des expériences BABAR et BELLE est proche de 10°. L’expérience LHCb auprès du LHC présente un fort potentiel d’amélioration pour ce paramètre de violation de CP, notamment via la désintégration Bd0 -> D0K*0, un des canaux clés de cette mesure. Les désintégrations D0 -> Kπ, D0 -> Kππ0 et D0 -> Kπππ sont étudiées dans cette thèse. L’utilisation de désintégrations faisant intervenir des π0 nécessite un bon étalonnage en énergie des calorimètres électromagnétiques. Une méthode d’étalonnage intercellules du ECAL basée sur le flux d’énergie, permet d’obtenir une inter-calibration de l’ordre de 1,5 %, l’échelle d’énergie absolue étant obtenue par des méthodes indépendantes non étudiées ici. La détermination du rapport d’embranchement de la désintégration Bs0 -> D0K*0, première étape du programme aboutissant à la mesure de la violation de CP dans le canal Bd0 -> D0K*0, est réalisée relativement au rapport d’embranchement de Bd0 -> D0ρ0. Le résultat final obtenu avec 36 pb−1 de données collectées par LHCb en 2010 reste dominé par l’erreur statistique :BR(Bs0 -> D0K*0)/BR(Bd0 -> D0ρ0) = 1, 48 ± 0, 34 (stat) ± 0, 15 (syst) ± 0, 12 (fd/fs). / The present status on the determination of the angle γ of the Cabibbo-Kabayashi-Maskawa Unitary Triangle is statistically limited by the rarity of b→ u transitions. The obtained precision combining results from the BABAR and BELLE experiments is close to 10°. The LHCb experiment at the LHC has a strong potential to reduce the uncertainty on this CP violation parameter, especially through the Bd0 -> D0K*0 decay, one of the key channels for this measurement. The D0 -> Kπ, D0 -> Kππ0 and D0 -> Kπππ decays are studied in this thesis. Decays involving π0 require an accurate energy calibration of electromagnetic calorimeters. An inter-calibration technique based on the energy flow allows to obtain the 1.5 % level, the absolute scale being obtained from independent methods studied elsewhere. The determination of the Bs0 -> D0K*0 decay branching ratio, first step towards a measurement of CP violation in the Bd0 -> D0K*0 channel, is performed relatively to the Bd0 -> D0ρ0 decay. The final result, obtained with 36 pb−1 of data collected by LHCb in 2010 is dominated by the statistical uncertainty:BR(Bs0 -> D0K*0)/BR(Bd0 -> D0ρ0) = 1, 48 ± 0, 34 (stat) ± 0, 15 (syst) ± 0, 12 (fd/fs).

Cette thèse de doctorat décrit la recherche de la production du boson de Higgs associée à une paire de quarks tops (tt̅H) dans un ensemble de données de collisions proton-proton à une énergie de centre de masse de √s = 13 TeV et avec une luminosité intégrée de 36,1 fb⁻¹, enregistrée par le détecteur ATLAS en 2015 et 2016. Sept états finaux, correspondants à différentes désintégrations du boson de Higgs, sont optimisés pour une meilleure séparation du signal par rapport au bruit de fond. Un excès d’événements par rapport au bruit de fond MS est observé avec une signification de 4,1 écarts types, tandis que 2,8 sont attendus. En combinaison avec des résultats de recherches avec d’autres canaux de désintégration du boson de Higgs, la production de tt̅H a été découverte par le détecteur ATLAS en utilisant jusqu’à 79,8 fb⁻¹ de données de collisions à √s = 7, 8 et 13 TeV.Les courants neutres, qui changent de saveur dans la désintégration du quark top en un boson de Higgs et un quark léger (t → Hq), sont fortement supprimés dans le MS. Des nouveaux modèles physiques peuvent prédire un rapport d’embranchement de t → Hc de 0,15%. La recherche de ces désintégrations, avec un état final à deux ou trois leptons, n’observe aucun signal. Une limite supérieure sur le ratio d’embranchement de t → Hc (t → Hu) avec un niveau de confiance de 95% est observé à 0,16% (0,19%) avec une limite attendue de 0,15% (0,15%).Pour contourner la limitation du nombre insuffisant des collisions, le LHC et ses expériences prévoient un plan de mise à niveau ambitieux. Un système de démonstration est en service depuis 2015 et ses performances étudiées avec des données de calibrations et de collisions. / This doctoral thesis describes the search for the associated Higgs boson production with a pair of top quarks (tt̅H) in a dataset of proton-proton collisions at a center-of-mass energy of √s = 13 TeV and with an integrated luminosity of 36.1 fb⁻¹, recorded by the ATLAS detector in 2015 and 2016. Seven final states, associated to different Higgs boson decay, are optimised to get the best signal to background separation. An excess of events over the SM background is observed with a significance of 4.1 standard deviations, while 2.8 are expected. In combination with search results obtained for other Higgs boson decay channels, the tt̅H production has been discovered with the ATLAS detector using up to 79.8 fb⁻¹ of collision data at √s = 7, 8 and 13 TeV.Flavour-changing neutral currents in top quark decays into a Higgs boson and a light up-type quark (t → Hq) are strongly suppressed in the SM. New physics models can predict a t → Hc decay branching ratio of 0.15%. The search for these decays in final states with two or three leptons observes no signal. An upper limit on the t → Hc (t → Hu) decay branching ratio at a 95% confidence level is set at 0.16% (0.19%) with an expected limit of 0.15% (0.15%).To bypass the limitation of an insufficient amount of collision data, the LHC and its experiments foresee an ambitious upgrade plan. The current ATLAS Liquid Argon Calorimeter readout will be replaced to get an increased granularity to improve the trigger selectivity and avoid bandwidth saturation at high luminosity. A demonstrator system has been operated since 2015 and its performance studied with calibration and collision data.