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Testing RPC Performance with Discharges Ignited by UV Laser Pulses: Precise measurement of gas parameters in approximately realistic RPC configurationsFan, Xingming 26 November 2019 (has links)
This thesis is devoted in two associated topics: a unique laser facility for researches of gaseous detectors; the investigations of Resistive Plate Chamber (RPC) detectors and the measurement of gas parameters in a realistic condition of timing RPC.
A pulsed UV laser test facility has been assembled in HZDR. The focus of pico-second laser pulses is placed in a specific position in a gaseous detector sample to produce laser plasma, where free electrons are generated in ionizations with well defined number, micro-meter spatial accuracy in a volume of micro-meter scale. It provides a method, independent from accelerators, to make investigations with gaseous detectors in a laboratory.
Samples of RPC detectors are designed and assembled for experiments with the laser test facility. Methods are developed to acquire the waveforms of electron avalanches for different drift lengths and to obtain the key gas parameters: the effective Townsend coefficient and the electron drift velocity. We have succeeded in the direct measurement of gas parameters at the field strength of timing RPC under atmospheric pressure for the first time in experimental conditions.
The research has obtained different achievements. The laser test facility is proven to be qualified for the measurement of gas parameters, and has a potential to contribute to the eco-gas research for future RPC. The possible measurement range of electric field of gas parameter at atmospheric pressure is extended by a factor of two, from the range of trigger RPC to timing RPC. The results of experiments have revealed some fundamental mechanisms, which will extend the understanding of RPC performance and electron avalanche process.
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A large area time of flight detector for the STAR experiment at RHICKajimoto, Kohei 29 June 2010 (has links)
A large area time of flight (TOF) detector based on multi-gap resistive plate chamber (MRPC) technology has been developed for the STAR (Solenoidal Tracker at RHIC) experiment at the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory, New York. The TOF detector replaces STAR's Central Trigger Barrel detector with 120 trays, each with 32 MRPCs. Each MRPC has 6 channels. The TOF detector improves by a factor of about 2 STAR's particle identification reach in transverse momenta and enhances STARs physics research program.
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RPCs design, development and tests for the Pierre Auger Observatory / Desenvolvimento, construção e testes de RPCs para o observatório Pierre AugerMartins, Victor Barbosa 20 August 2018 (has links)
The cosmic rays are the most energetic particles in the universe. Their production, propagation, and detection are objects of studies. Surface detectors aim to identify particles from extensive air showers (EAS) which the result from the cosmic-ray interactions with the atmosphere. Resistive Plate Chambers (RPCs) have shown to be a suitable muon detector to be integrated into the Pierre Auger Observatory. An instrumentation was developed to assembly RPCs in São Carlos (BRA). Data from RPCs already built by our collaborators in Coimbra (POR) were analyzed. The detector efficiency to muons was calculated and is approximately 88%, which is in good agreement with the values quoted in the literature. Direction maps were built to investigate the muon incoming direction and the quantity of matter traversed by the muons. The dependence of the muon flux on the zenith angle was calculated and compared with results from the simulation. A square cosine dependence is expected, though it is seen that the building structure has enough matter to block some of the incident muons and alter the dependence curve. The total muon flux was estimated based on the detector efficiencies and solid angle as 1.6.10−5. mm−2.sr−1. s−1 compared with the literature value of 7.1.10−5 mm−2.sr−1.s−1, which gives an absorption by the building of approximately 77%. / Os raios cósmicos são as partículas mais energéticas do universo. Sua produção, propagação e detecção são objetos de estudos. Os detectores de superfície têm como objetivo identificar partículas dos chuveiros atmosféricos extensos (EAS), o qual é o resultado das interações do raio cósmico com a atmosfera. A Câmaras de Placas Resistivas (RPCs) demonstra ser um detector de múons adequado para ser integrado ao Observatório Pierre Auger. Foi desenvolvida em São Carlos (BRA) uma instrumentação para montagem de RPCs. Dados de RPCs já construídas por nossos colaboradores em Coimbra (POR) foram analisados. A eficiência dos detectores para múons foi calculada como sendo de aproximadamente 88%, o que está de acordo com os valores citados na literatura. Mapas de direção foram construídos para investigar a direção de chegada e a quantidade de matéria atravessada pelos múons. A dependência do fluxo de múons com o ângulo zenital foi comparada com os resultados da simulação. Embora uma dependência com o quadrado do cosseno é esperada, foi constatado que a estrutura do prédio tem matéria suficiente para bloquear parte dos múons incidentes e alterar a curva da dependência. O fluxo total de múons foi estimado baseado nas eficiências do detector e no ângulo sólido é de 1.6.10−5 mm−2.sr−1.s−1. Comparado com o valor da literatura de 7.1.10−5 mm−2.sr−1.s−1 resulta em uma absorção pelo prédio de aproximadamente 77% do fluxo de múons.
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RPCs design, development and tests for the Pierre Auger Observatory / Desenvolvimento, construção e testes de RPCs para o observatório Pierre AugerVictor Barbosa Martins 20 August 2018 (has links)
The cosmic rays are the most energetic particles in the universe. Their production, propagation, and detection are objects of studies. Surface detectors aim to identify particles from extensive air showers (EAS) which the result from the cosmic-ray interactions with the atmosphere. Resistive Plate Chambers (RPCs) have shown to be a suitable muon detector to be integrated into the Pierre Auger Observatory. An instrumentation was developed to assembly RPCs in São Carlos (BRA). Data from RPCs already built by our collaborators in Coimbra (POR) were analyzed. The detector efficiency to muons was calculated and is approximately 88%, which is in good agreement with the values quoted in the literature. Direction maps were built to investigate the muon incoming direction and the quantity of matter traversed by the muons. The dependence of the muon flux on the zenith angle was calculated and compared with results from the simulation. A square cosine dependence is expected, though it is seen that the building structure has enough matter to block some of the incident muons and alter the dependence curve. The total muon flux was estimated based on the detector efficiencies and solid angle as 1.6.10−5. mm−2.sr−1. s−1 compared with the literature value of 7.1.10−5 mm−2.sr−1.s−1, which gives an absorption by the building of approximately 77%. / Os raios cósmicos são as partículas mais energéticas do universo. Sua produção, propagação e detecção são objetos de estudos. Os detectores de superfície têm como objetivo identificar partículas dos chuveiros atmosféricos extensos (EAS), o qual é o resultado das interações do raio cósmico com a atmosfera. A Câmaras de Placas Resistivas (RPCs) demonstra ser um detector de múons adequado para ser integrado ao Observatório Pierre Auger. Foi desenvolvida em São Carlos (BRA) uma instrumentação para montagem de RPCs. Dados de RPCs já construídas por nossos colaboradores em Coimbra (POR) foram analisados. A eficiência dos detectores para múons foi calculada como sendo de aproximadamente 88%, o que está de acordo com os valores citados na literatura. Mapas de direção foram construídos para investigar a direção de chegada e a quantidade de matéria atravessada pelos múons. A dependência do fluxo de múons com o ângulo zenital foi comparada com os resultados da simulação. Embora uma dependência com o quadrado do cosseno é esperada, foi constatado que a estrutura do prédio tem matéria suficiente para bloquear parte dos múons incidentes e alterar a curva da dependência. O fluxo total de múons foi estimado baseado nas eficiências do detector e no ângulo sólido é de 1.6.10−5 mm−2.sr−1.s−1. Comparado com o valor da literatura de 7.1.10−5 mm−2.sr−1.s−1 resulta em uma absorção pelo prédio de aproximadamente 77% do fluxo de múons.
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Caractérisation de détecteurs à plaques résistives de verres de basse résistivité en vue de la mise à niveau de CMS / Characterisation of low resistivity glass resistive plate chambers for the CMS upgradeLagarde, François 20 October 2017 (has links)
La mise à niveau du détecteur CMS (Upgrade Phase-2) en 2024 prévoit l'installation de nouveaux détecteurs à plaques résistives (RPC) dans les 2 secteurs les plus externes et les plus vers l’avant (RE3/1 et RE4/1) des bouchons. Des RPC en verre de basse résistivité (GRPC) ont été proposées afin d'instrumenter ces secteurs où le flux de particules sera de l’ordre du kHz/cm², valeurs pour lesquelles les RPC actuelles de CMS ne sont pas efficaces. Cette thèse porte sur l'étude et la caractérisation de ces GRPC, de leur électronique de lecture associée et de leur résistance aux irradiations. Deux méthodes de production de chambres de taille moitié des chambres finales à partir de pavages de verres de taille maximale 32*30cm² ont été élaborées et testées. Un nouveau circuit électronique (PCB) à bandes de détection non segmentées en êta et lues par des puces dédiées (PETIROC2A) est également présenté. Il permet grâce à des chronomètres numériques (TDC) de 25 picosecondes de résolution, une précision de l'ordre du centimètre sur la mesure de la position du passage des particules le long des bandes. Cette thèse décrit ces nouveaux dispositifs et présente les résultats obtenus avec ceux-ci lors de tests en faisceaux auprès des accélérateurs PS et SPS du CERN ainsi qu'au Gamma Irradiation Facility (GIF++). Cette étude montre que le verre de basse résistivité, bien que supportant les flux de particules, n'est pas la meilleure solution pour l'environnement de CMS car il nécessite un mélange gazeux différent pour fonctionner. Cependant, la nouvelle électronique a prouvé son adéquation à cet environnement et est maintenant considérée comme l'option privilégiée pour la mise à niveau de CMS / The installation of new resistive plate chamber detectors (RPCs) in the 2 most remote sectors (RE3 / 1 and RE4 / 1) of the CMS End-Caps is planned during the Phase-2 CMS upgrade in 2024. Glass Resistive Plate Chambers (GRPC) with low resistivity glass as electrodes have been proposed to equip these sectors. These detectors should sustain these zones' particle rate. The aim of this Thesis is to study and characterise these detectors, their associated readout electronics and their behaviour under radiations.Two ways of building half size chambers by tesselation of glass plates with maximal size 32*30cm² have been developped. A new PCB with strips readout read by dedicated ASICs (PETIROC2A) without eta segmentation is also described. It allows, thanks to a 25 ns time-resolution TDC to estimate the particle crossing position on the strip with a resolution of the order of cm. This manuscript describes all these devices and discusses the devices' performance measured in beam tests done at the CERN PS and SPS accelerator and at the Gamma Irradiation Facility (GIF++). This study shows that the low resistivity glass, though able to sustain the particule rate, is not the best option for the CMS upgrade. On the contrary, the tested electronic has been proven to fit the CMS upgrade requirements and is now considered as the baseline of the CMS End-Caps RPC upgrade project
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