Neste trabalho, foram realizadas medidas das partículas coincidentes produzidas na reação 9Be+12C à energia ELab=21MeV, com o objetivo de obtermos a seção de choque referente ao processo de breakup nuclear do 9Be para o canal 9Be 8Be+n + + n. Realizamos também medidas das distribuições angulares para o canal elástico 9Be(12C,9Be)12C nas energias próximas à barreira Coulombiana (ELab=13, 14.5, 17.32, 19 e 21MeV), com o objetivo de observar possíveis anomalias no potencial óptico que indicassem os efeitos do breakup nuclear. Na medida das partículas alfa coincidentes, observamos que elas são produzidas no decaimento do 8Be para seu estado fundamental, não sendo observado nenhum outro estado. Ao reconstruirmos o núcleo de 8Be original a partir dessas alfas, observamos que os espectros de energia apresentam duas regiões distintas. A primeira em energias mais altas, onde observamos a presença de picos bem definidos que remetem aos estados discretos do núcleo residual de 13C produzido no processo de transferência de nêutrons. E uma segunda região de baixas energias em que há uma estrutura contínua e suave relacionada com o breakup nuclear. Os resultados experimentais para o canal elástico foram analisados utilizando o potencial de São Paulo, as normalizações da parte real (Nr) e imaginária (Ni) foram ajustadas de forma a descrever os dados em ângulos frontais. Para os ângulos intermediários, as seções de choque apresentaram um visível aumento nas energias de 17.32, 19 e 21MeV, o qual foi atribuído ao mecanismo de transferência elástica. / In this work we performed particle coincidence measurements for the 9Be+12C nuclear reaction at ELab=21MeV in order to obtain information about the breakup of 9Be 8Be+n + +n. We observe evidences of nuclear breakup by reconstructing 8Be ground state particles. From the systematics analysis of the 8Be energy spectrum we observe two different situations: i) at high energies there are evidences which support that the main reaction mechanism is nucleon transfer, and ii) at low energies, a continuum region maybe related to the 9Be breakup process. Further studies are necessary to confirm those hypotheses. In order to check breakup threshold anomalies into the optical potential, we also measured elastic angular distributions at energies around the Coulomb barrier (ELab=13, 14.5, 17.32, 19 e 21MeV). The data were analyzed in the framework of the São Paulo potential, where the normalization of the real and imaginary potential was adjusted to obtain a good description of data at forward angles. At 17.32, 19 and 21MeV, the elastic cross section shows an enhancement at intermediate and backward angles. This can be explained by the elastic transfer mechanisms.

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Neste trabalho é apresentado o protótipo de um detector a gás sensível à posição em duas dimensões para aplicação com experimentos de espalhamento e difração de raios X. Partiu-se de um detector inicialmente desenvolvido para outras aplicações e mostrou-se as modificações necessárias no conceito original do dispositivo. As estratégias adotadas para determinar as adaptações essenciais foram: pesquisar na literatura sobre as características de um detector multifilar para raios X (escolha do gás, da pressão, da janela, etc.), uso de simulações, implementação das mudanças e realização de testes. Ferramentas computacionais foram usadas para estimar a resistência mecânica e a atenuação de fótons de raios X que ajudaram na determinação do material para a construção da janela de entrada. Simulações do detector foram construídas com o programa Garfield e serviram para o estudo do funcionamento do detector, além de determinar os parâmetros ótimos de operação do equipamento, como a distância entre os fios e diâmetro dos mesmos, além da diferença de potencial a ser aplicada, entre muitos outros parâmetros. Os resultados obtidos mostraram que o conceito do detector multifilar com as devidas adaptações permitem o funcionamento desse dispositivo para detecção de raios X. No entanto, dependendo da aplicação, pode ser necessário aprimorar a resolução do equipamento, a fim de ter uma melhor descrição dos dados coletados. São apontadas algumas ideias para esse aprimoramento. Apresentam-se também resultados interessantes obtidos com um detector de padrão microscópico chamado de triplo GEM. Esse dispositivo pertence ao laboratório de desenvolvimento de detectores a gás (GDD Group) do CERN e foi utilizado em um trabalho nessa instituição. Os resultados mostraram o potencial do equipamento para detecção de raios X. Os resultados e simulações apresentadas nesse trabalho confirmaram que as mudanças no conceito original do detector permitem seu uso na detecção de raios X. Além disso, foi possível obter várias indicações para uma maior otimização, que pode melhorar sua resolução e estabilidade. O conhecimento adquirido sobre o programa Garfield é fundamental nesse processo, uma vez que é possível propor mudanças e testá-las no computador. Essas melhorias podem ser empregadas em uma nova versão desse detector que será construído nos laboratórios do Instituto de Física da Universidade de São Paulo (IFUSP). Pode-se indicar ainda a possibilidade do uso de detectores GEM aplicados aos experimentos de espalhamento e difração de raios X. É necessário ressaltar que o grupo de Suaide et al. do departamento de Física Nuclear do IFUSP já trabalha com a tecnologia GEM, porém focada em outras aplicações. / This work presents the prototype of a 2D position sensitive gas detector for application in X-ray scattering and diffraction experiments. Starting from a detector initially developed for other applications and will show the required changes on the original concept of this device. The strategy used to determine the necessary adaptations were based on searching in the literature for the overall characteristics of a multi-wire X-ray detector (choice of gas, pressure, window, etc.), the use of simulations, implementation of the changes and finally operational tests. Computational tools were used to calculate the mechanical strength and attenuation of the X-ray photons that helped to determine the most appropriate material for the construction of the entrance window. Detector simulations were built with Garfield software and were used to study the overall properties of the detector, and to determine the optimum parameters for the equipment operation. Typical parameters are the distance between the wires, wire diameter, high voltage to be used, among several other parameters. The results obtained showed that the multi-wire detector concept with the implemented adaptations allowed the detection of X-rays. However, depending on the application, it may be necessary improve the resolution of the equipment, in order to have a better description of the collected data. Several ideas are suggested for this improvement. It is also presented interesting results obtained with a microscopic pattern detector called triple GEM. This device belongs to the Gas Detectors Development group (GDD group) at CERN and was used in my training at this institution. The results showed the potential of the equipment for detection of X-rays. The results and simulations presented in this work, confirmed that the changes in the concept of the original detector permitted it use on X-ray detection applications. Also, it was possible to obtain several indications for further optimization, which may improve its resolution and stability. The acquired knowledge on the software Garfield is essential on this process since it is possible to propose changes and test it in the computer. Such improvements may be use in a new version of this detector which will be built at the laboratories of the Institute of Physics (University of São Paulo - IFUSP). We also indicate the possibility of use of GEM detectors for X-ray scattering and diffraction experiments. It is necessary to emphasize that the group of Professor Alexandre Suaide and collaborators at Nuclear Physics department (IFUSP) already work with the GEM technology, but focused on other applications.

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Neste trabalho, foram realizadas medidas das partículas coincidentes produzidas na reação 9Be+12C à energia ELab=21MeV, com o objetivo de obtermos a seção de choque referente ao processo de breakup nuclear do 9Be para o canal 9Be 8Be+n + + n. Realizamos também medidas das distribuições angulares para o canal elástico 9Be(12C,9Be)12C nas energias próximas à barreira Coulombiana (ELab=13, 14.5, 17.32, 19 e 21MeV), com o objetivo de observar possíveis anomalias no potencial óptico que indicassem os efeitos do breakup nuclear. Na medida das partículas alfa coincidentes, observamos que elas são produzidas no decaimento do 8Be para seu estado fundamental, não sendo observado nenhum outro estado. Ao reconstruirmos o núcleo de 8Be original a partir dessas alfas, observamos que os espectros de energia apresentam duas regiões distintas. A primeira em energias mais altas, onde observamos a presença de picos bem definidos que remetem aos estados discretos do núcleo residual de 13C produzido no processo de transferência de nêutrons. E uma segunda região de baixas energias em que há uma estrutura contínua e suave relacionada com o breakup nuclear. Os resultados experimentais para o canal elástico foram analisados utilizando o potencial de São Paulo, as normalizações da parte real (Nr) e imaginária (Ni) foram ajustadas de forma a descrever os dados em ângulos frontais. Para os ângulos intermediários, as seções de choque apresentaram um visível aumento nas energias de 17.32, 19 e 21MeV, o qual foi atribuído ao mecanismo de transferência elástica. / In this work we performed particle coincidence measurements for the 9Be+12C nuclear reaction at ELab=21MeV in order to obtain information about the breakup of 9Be 8Be+n + +n. We observe evidences of nuclear breakup by reconstructing 8Be ground state particles. From the systematics analysis of the 8Be energy spectrum we observe two different situations: i) at high energies there are evidences which support that the main reaction mechanism is nucleon transfer, and ii) at low energies, a continuum region maybe related to the 9Be breakup process. Further studies are necessary to confirm those hypotheses. In order to check breakup threshold anomalies into the optical potential, we also measured elastic angular distributions at energies around the Coulomb barrier (ELab=13, 14.5, 17.32, 19 e 21MeV). The data were analyzed in the framework of the São Paulo potential, where the normalization of the real and imaginary potential was adjusted to obtain a good description of data at forward angles. At 17.32, 19 and 21MeV, the elastic cross section shows an enhancement at intermediate and backward angles. This can be explained by the elastic transfer mechanisms.

Naturally occurring biological nanoparticles (BNPs) and synthetic nanoparticles have a significant role in a wide range of biomedical applications. For instance, direct detection of BNPs, such as viruses, can provide new methods of viral diagnostics while synthetic particles can be used as labels to indirectly detect biomarkers for drug discovery. Therefore, developing advanced tools for nanoparticle detection has gained popularity in biotechnological research. One of the most exciting recent developments in BNP detection has been single particle (or digital) counting of individual particles which offers unprecedented sensitivity levels. However, standard optical techniques face a significant challenge for nanoparticle detection, due the weak optical contrast of sub-wavelength particles. Interferometric microscopy, overcomes the limitations imposed by particle size which allows for visualizing unresolved (diffraction-limited) optical signatures of sub-wavelength particles. Single-particle interferometric reflectance imaging sensor (SP-IRIS), is a widefield microscopy platform, developed by our group over the last years. SP-IRIS uses interferometric enhancement and a layered substrate to increase the optical contrast for the target particles of interest. While this microscopy technique has shown remarkable sensitivity levels for numerous applications including detection of viral particles and nucleic acids, it has remained a specialty tool due to the utilization of z-scan measurements for extracting the optical signature of particles. The z-scan measurements that consist of multiple frames acquired at different focal positions impose two major drawbacks. The first is the requirement of repeatable and high resolution scanning optics and the second is the time and computational processing power required to analyze the image stacks. In this thesis we describe a novel imaging method termed `pixel-diversity‘ IRIS (PD-IRIS), which aims to provide a more practical detection method for nanoparticles by eliminating the need for acquiring z-stacks. PD-IRIS is built upon SP-IRIS, however it introduces a paradigm shift for encoding the necessary optical signature of target particles. PD-IRIS compresses the relevant optical information within a single image frame rather than an image stack. This is achieved by using camera sensors that simultaneously record multiple spectral or polarization channels. Therefore, a single image can record distinct spectral responses of target particles with respect to different excitation wavelengths (multi-spectral PD-IRIS) or the distinct scattering characteristics with respect to polarization (polarization PD-IRIS). This dissertation presents a rigorous study for both PD-IRIS modes and demonstrates the practical applications of nanoparticle detection with proof-of-concept measurements. / 2024-01-16T00:00:00Z

The stainless steel industry is an industry which manufactures one of the most used ma-terials in the world. Even though the vast size of the industry many might not reflect werethe steel comes from when buying their IKEAcutlery etc. But in fact this industry is moreintricate and complex than one might think.During the manufacturing process, the steelgoes through several processes. One of thoseprocesses is done by treating the steel withstrong acid. This chemical process is calledpickling. The pickling process is what createsthe characteristic smooth and shiny surface ofa product made in stainless steel.This thesis is about the development of a testunit that is able to effectively test the ASRA(Acid Sludge Removal Apparatus) filter cloths.The ASRA is a filtration system developed by Scanacon in Stockholm that filtrates and puri-fies acid that is used during the pickling pro-cess of a steel manufacture process. Today, it is complicated, time consuming and dangerous totest and evaluate different filter cloths in orderto find the cloth that provides the best result,since the tests has to be conducted on the realsystems. The aim of this thesis was therefore tosolve these problems. Scanacon wanted to findan alternative solution, that would not includeinteraction with the real filtration system. Theyalso wanted a portable and safe solution. To solve the problem a iterative design pro-cess called RDCD which stands for research, design, create & delivery was developed. Theprocesses was heavily influenced by the CDIO process (Conceive, Design, Implement & Ope-rate). After the research phase was conducted it was decided that a small filter analysis productwould be the best way to solve the problem. The product was then developed one com-ponent at a time. During the project several prototypes and test was created and conductedin order to validate the design.The result is a small filtration unit speciallydesigned to simulate the ASRA system. Theproduct is able to rapidly test various filtercloths in an easy way, without putting the user in harm’s way. After the tests has been perfor-med can the user can identify which cloth that worked the best. The product is small enoughto be possible to be carried in a hard case bag,which in turn affords portability. / Stålindustrin är en industri som tillverkar ettav de mest använda materialen i världen. Trotsindustrins enorma storlek är det kanske intemånga som reflekterar varifrån stålet kommerifrån när man köper exempelvis IKEA bestick.Men faktum är att den här industrin är mycketmer invecklad och komplex än vad man kan tro. Under tillverkningsprocessen går stålet ige-nom flera processer. En av de här processerna genomförs genom att behandla stålet med starksyra. Den kemiska processen kallas för betningoch är det som ger en produkt tillverkad i stålden karaktäristiska lena och glänsande ytan. Den här examensrapporten handlar om ut-vecklandet av en test enhet som effektivt kan testa filter dukarna till ASRA (Acid SludgeRemoval Apparatus) systemet. ASRA systemetär ett filtreringssystem utvecklat av Scanaconi Stockholm som filtrerar och renar syran som används under betningsprocessen vid stål-tillverkning. Idag är det komplicerat, tidskrä-vande och farligt att testa och utvärdera olika filterdukar för att ta reda på vilken duk somger bäst resultat, eftersom att testerna måstegenomföras på de riktiga systemen. Målet fördet här examensarbetet var därför att lösa dehär problemen. Scanacon ville ha en alternativlösning som inte kräver interaktion med deriktiga systemen. De ville också ha en portabeloch säker lösning. För att lösa problemet utvecklades en itera-tiv designprocess kallad RDCD som står för research, design, create & delivery. Processen var tungt influerat av CDIO (Conceive, De-sign, Implement & Operate) processen. Efter att researchfasen var genomförd bestämdesdet att en liten filteranalysatorprodukt var detbästa sättet att lösa problemet på. Produktenutvecklades sedan en komponent i taget. Underprojektets gång har flera prototyper byggts och flera tester genomförts för att validera designen. Resultatet är en liten filtreringsenhet som är specialdesignad för att simulera ASRA syste-met. Produkten kan snabbt testa oliak filterdu-kar på ett enkelt sätt, utan utsätta användaren för fara. Efter att testerna genomförts kananvändaren identifiera vilken duk som funkatbäst. Produkten är tillräckligt liten för att fåplats i en hårdplast väska, vilket ger produktenden efterfrågade portabiliteten.

This thesis focuses on inductive base sensor design at MHz range frequency. The background theory, design, experiments and results for a new magnetic particles sensor is presented. A new magnetic sensor based on a planar coil was investigated for DNA pathogen detection. Change in inductance of the planar coil due to the presence of magnetic particles with varying mass was measured. The experimental set-up consisted of different sized planar coil with associated electronics for inductance measurements. The best sensor performance was accomplished using two different inductors while oscillating at frequencies 2.4MHz using 9.5μH inductor and 7.2MHz with 85μH inductor. The sensor has very large signal to noise ratio (580×103), while the average amount of frequency drift was 0.58. This sensor was tested with various types of magnetic particles. In addition, iron-oxide nanoparticles were synthesized through water in oil microemulsion method and with an average size of 25nm. The best sensitivity achieved for detection of 50μg iron-oxide particles was with the bead size of 10nm. 81Hz frequency shift was attained in regard to that amount of particles. This research shows that increasing the resonance frequency to 7.2MHz can cause the larger output signal difference (frequency shift) in the presence of magnetic particles; however, the sensor stability is the most important factor for determining the detection resolution and sensitivity. The sensitivity is better if the sensor can detect smaller amount of magnetic sample. The results of this research demonstrate that while the sample consists of smaller size particles, the sensor can detect the lower amount of sample. This is due to the heating effect of nanoparticles. On the other hand the sample distance from the sensor has a major impact on the sensitivity too; the shorter the distance, the higher the sensitivity. This technique can potentially be extended to detect several different types of bacterial pathogens and can be modified for multiplex quantitative detection. This sensing technique will be incorporated into a handheld, disposable microfluidic chip for point-of-care diagnostics for sexually transmitted diseases.

A hipótese de que a matéria estranha de quarks (um plasma composto por quarks up, down e strange em quantidades aproximadamente iguais) é estável `a pressão nula vem sendo considerada há mais de vinte anos, tanto teoricamente quanto em experimentos específicos para sua eventual detecção. Se a matéria estranha é de fato estável, então poderia haver importantes implicações para a Astrofísica. Entre as mais estimulantes destas implicações está a possibilidade de conversão da matéria nuclear ordinária em matéria estranha no interior das estrelas de nêutrons devido ás altíssimas densidades ali encontradas. Processos tais como coalescência em binárias de estrelas de nêutrons e as próprias supernovas, eventos responsáveis pelo nascimento destas estrelas, poderiam ejetar estruturas finitas de matéria estranha, chamadas strangelets (equivalentes aos núcleos), no meio interestelar. Desta forma, strangelets estariam presentes entre os primários de raios cósmicos e seriam sujeitas a processos elementares análogos aos núcleos ordinários. Nesta Tese, as strangelets são estudadas desde os prováveis sítios para sua produção astrofísica, passando por interações com a matéria do meio interestelar, ate a chegada ás imediações terrestres. Estima-se o fluxo de strangelets de baixa energia que poderia ser mantido aprisionado na magnetosfera da Terra, bem como são estudados os processos de suas interações com componentes da atmosfera, com vistas às assinaturas observacionais então resultantes. Desta forma, são determinadas as características relevantes para a identificação destes exóticos por experimentos que testam o fluxo de raios cósmicos, ajudando na melhor compreensão das propriedades da matéria nuclear em alta densidade bariônica e baixa temperatura. / The strange quark matter hypothesis, which states that a plasma composed of quarks up, down and strange in roughly equal amounts is absolutely stable at zero pressure, has been studied for more than twenty years, both theoretically and during searches for its detection in specific experiments. If strange quark matter is indeed stable, then there could be important implications for the field of Astrophysics. Among the most stimulating ones is the possibility of conversion of ordinary nuclear matter in strange quark matter in the interior of neutron stars due to the extremely high densities reached in the core of these compact objects. Processes such as the merger in neutron star binaries systems and supernovae themselves, responsible for the birth of these stars, may eject lumps of strange quark matter, termed strangelets, in the interstellar medium. In this way, strangelets may be present among the cosmic ray flux and be subjected to elementary processes much in the same way as ordinary nuclei. In this Thesis, strangelets are studied from their likely astrophysical production sites, passing through the interstellar medium until they reach the Earth neighborhood. Estimates of the low energy flux of strangelets that could be trapped in the terrestrial magnetosphere are given. Also, the interaction of these particles with components in the Earth atmosphere are studied with the aim of providing better understanding of the resulting observational signatures. It allows the determination of the relevant characteristics for the identification of these exotics by experiments testing the cosmic ray flux, helping to better understand the properties of nuclear matter at high densities and low temperatures.

Foram medidas distribuições angulares do espalhamento elástico 17O + p e da reação de transferência p(17O,a)14N nas energias ECM = 1,39 e 2,33 MeV. Foi utilizado feixe de 17O produzido no Laboratório Pelletron, com energias de 25 e 42 MeV. As medidas foram efetuadas utilizando-se alvos plásticos de mylar aluminizado (C10H10O4) e polietileno (CH2) com espessuras de 354µg/cm² e 6mg/cm², respectivamente. As distribuições angulares experimentais do espalhamento elástico e da reação de transferência foram analisadas por cálculos de Modelo Óptico e Aproximação de Born de Ondas Distorcidas (DWBA), ambos levando em conta uma estimativa da contribuição do núcleo composto através de cálculos de Hauser-Feshbach. Em 42 MeV, foi medida uma função de excitação do espalhamento elástico utilizando o Método de Espalhamento Ressonante com alvo grosso de (CH2). Várias ressonâncias do núcleo composto 18F são observadas. / Angular distributions of the elastic scattering 17O + p and of the transfer reaction p(17O, a)14N have been measured at the energies, ECM = 1.39 and 2.33 MeV. The 17O beam was produced by the Pelletron accelerator at the energies of 25 and 42 MeV. The measurements have been performed using plastic targets of aluminized mylar (C10H10O4) and polyethylene (CH2) with thicknesses 354µg/cm² and 6mg/cm², respectively. The experimental angular distributions of the elastic scattering and of the transfer reaction have been analyzed by optical model and Distorted Waves Born Approximation (DWBA) calculations, both taking into account the compound nucleus contribution via Hauser-Feshbach calculations. At 42 MeV, an excitation function of the elastic scattering has been measured using the Resonant Scattering Method with thick targets of (CH2). Resonances in the 18F compound nucleus are observed.