The work for this thesis is in line with the field of Instrumentation for Particle Accelerators, so called Beam Diagnostics. It is presented the development of a series of electro-mechanical devices called Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM). A full set of 17 BPM units (16 + 1 spare), named BPS units, were built and installed into the Test Beam Line (TBL), an electron beam decelerator, of the 3rd CLIC Test Facility (CTF3) at CERN ¿European Organization for the Nuclear Research¿. The CTF3, built at CERN by an international collaboration, was meant to demonstrate the technical feasibility of the key concepts for CLIC ¿Compact Linear Collider¿ as a future linear collider based on the novel two-beam acceleration scheme, and in order to achieve the next energy frontier for a lepton collider in theMulti-TeV scale. Modern particle accelerators and in particular future colliders like CLIC requires an extreme alignment and stabilization of the beam in order to enhance its quality, which rely heavily on a beam based alignment techniques. Here the BPMs, like the BPS-IPU, play an important role providing the beam position with precision and high resolution, besides a beam current measurement in the case of the BPS, along the beam lines. The BPS project carried out at IFIC was mainly developed in two phases: prototyping and series production and test for the TBL. In the first project phase two fully functional BPS prototypes were constructed, focusing in this thesis work on the electronic design of the BPS on-board PCBs (Printed Circuit Boards) which are based on transformers for the current sensing and beam position measurement. Furthermore, it is described the monitor mechanical design with emphasis on all the parts directly involved in its electromagnetic functioning, as a result of the coupling of the EM fields generated by the beam with those parts. For that, it was studied its operational parameters, according the TBL specifications, and it was also simulated a new circuital model reproducing the BPS monitor frequency response for its operational bandwidth (1kHz-100MHz). These prototypes were initially tested in the laboratories of the BI-PI section¿Beam Instrumentation - Position and Intensity¿ at CERN. In the second project phase the BPS monitor series, which were built based on the experience acquired during the prototyping phase, the work was focused on the realization of the characterization tests to measure the main operational parameters of each series monitor, for which it was designed and constructed two test benches with different purposes and frequency regions. The first one is designed to work in the low frequency region, between 1kHz-100MHz, in the time scale of the electron beam pulse with a repetition period of 1s and an approximate duration of 140ns. This kind of test setups called Wire Test-bench are commonly used in the accelerators instrumentation field in order to determine the characteristic parameters of a BPM (or pick-up) like its linearity and precision in the position measurement, and also its frequency response (bandwidth). This is done by emulating a low current intensity beam with a stretched wire carrying a current signals which can be precisely positioned with respect the device under test. This test bench was specifically made for the BPS monitor and conceived to perform the measurement data acquisition in an automated way, managing the measurement equipment and the wire positioning motors controller from a PC workstation. Each one of the BPS monitors series were characterized by using this system at the IFIC labs, and the test results and analysis are presented in this work. On the other hand, the high frequency tests, above the X band in the microwave spectrum and at the time scale of the micro-bunch pulses with a bunching period of 83ps (12GHz) inside a long 140ns pulse, were performed in order to measure the longitudinal impedance of the BPS monitor. This must be low enough in order to minimize the perturbations on the beam produced at crossing the monitor, which affects to its stability during the propagation along the line. For that, it was built the high frequency test bench as a coaxial waveguide structure of 24mm diameter matched at 50¿ and with a bandwidth from 18MHz to 30GHz, which was previously simulated, and having room in the middle to place the BPS as the device under test. This high frequency test bench is able to reproduce the TEM (Transversal Electro-Magnetic) propagative modes corresponding to an ultra-relativistic electron beam of 12GHz bunching frequency, so that the Scattering parameters can be measured to obtain the longitudinal impedance of the BPS in the frequency range of interest. Finally, it is also presented the results of the beam test made in the TBL line, with beam currents from 3.5A to 13A (max. available at the moment of the test). In order to determine the minimum resolution attainable by a BPS monitor in the measurement of the beam position, being the device figure of merit, with a resolution goal of 5¿m at maximum beam current of 28A according to the TBL specifications. / García Garrigós, JJ. (2013). Development of the Beam Position Monitors for the Diagnostics of the Test Beam Line in the CTF3 at CERN [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34327 / TESIS

La thèse est axée sur l'étude des effets collectifs dans un anneau de stockage d'électrons de 50 MeV, ThomX, en l'absence d'amortissement synchrotron et d’adaptation longitudinale. Cette thèse est divisée en deux parties distinctes. La première partie correspond à la conception du modèle d'impédance (champ de sillage géométrique, résistif et rayonnement synchrotron cohérent) de l'anneau de stockage afin de simuler la dynamique faisceau. Le modèle d'impédance géométrique de l'anneau de stockage a été obtenu par la simulation des éléments individuels et a été vérifié en utilisant des mesures RF sur des prototypes. Le rayonnement synchrotron cohérent a été simulé en tenant compte d'une chambre à vide rectangulaire. Des simulations de la dynamique faisceau, de la cathode de canon RF à l'anneau de stockage, comprenant les effets collectifs sont présentées. Les simulations sont utilisées pour optimiser la dynamique faisceau dans l'anneau de stockage dans le régime de micro-paquet. La deuxième partie concerne l'étude du nuage d'ions produit par l'ionisation des molécules du vide résiduel et l'optimisation des techniques de nettoyage des ions. Les points d'accumulation longitudinaux des ions et le piégeage dans les champs magnétiques sont tous les deux étudiés analytiquement et en utilisant un programme développé à cet effet. Les électrodes de nettoyage et les espaces de nettoyages sont simulés et optimisés en utilisant ce code et la stratégie choisie pour la limitation des effets induits par les ions est décrite. Enfin, les effets de la multi-ionisation et de la dissociation ionique sont pris en compte et l'effet des ions sur le faisceau d'électrons est estimé. / The thesis is focused on the study of collective effects in a 50 MeV electron storage ring, ThomX, in the absence of synchrotron radiation damping and of longitudinal matching. This thesis is divided in two distinct parts. The first part corresponds to the design of the impedance model (geometric and resistive wakefields, coherent synchrotron radiation) of the storage ring in order to simulate the beam dynamics. The geometric impedance model of the storage ring was obtained via simulation of the individual elements and was checked using wire measurements on prototypes. The coherent synchrotron radiation was simulated taking into account a rectangular vacuum chamber. Beam dynamics simulations, from the RF gun cathode to the storage ring, including collective effects are presented. The simulations are used to optimise the beam dynamics in the storage ring in the micro-bunching regime. The second part is the study of the ion cloud produced by the ionisation of the residual vacuum molecules and the optimisation of the ion clearing techniques. The longitudinal ion accumulation points and the trapping in magnetic fields are both studied analytically and by using a tracking code developed for this purpose. Clearing electrodes and clearing gaps are simulated and optimised using this code and the strategy chosen for the limitation of ion induced effects is described. Finally, the effect of multi-ionisation and ion dissociation is taken into account and the ion effect on the electron beam is estimated.

Innovation entrepreneurship is built not only on a quality idea, but also on the availability of start-up capital and management skills of the idea owner. The insufficient finance often limits the success and growth potential of start-ups. When seeking support to individual business plans, allowing for entry of a business angel could be an option. Business angels are private, mostly experienced investors who invest in SMEs with high growth potential not only financial capital, but also business know-how, contacts and management experience. Thesis evaluates possibilities to use venture capital offered by business angels to support innovative start-ups and on several case studies assesses readiness of innovation and business environment from the investors’ point of view.

This diploma thesis should bring not only working machine into the branch of agricultural industry, but also new approach to design. Obviously, the contribution of technical innovations, which are required in this segment, is concerned, too. All knowledge and concepts come from the practise of this field. The project partly takes up the pre-diploma thesis called Vision of the agricultural cutting machine with container arrangement and shares some details of the concept as such. The technical part was solved during the winter term within the scope of the subject Machines and equipment. From this project will be adopted all bases of constructional innovations of agricultural machine concept.

This paper deals with possibilities and functions of modern graphic accelerators and with measuring performance under OpenGL interface. Widespread algorithms to render scene in real-time are used. It focuses on how to test every part of accelerator's graphic pipeline as well as measure performance in rendering of advanced effects and theoretical speed at general purpose calculations through graphic processor. This testing is realized by implementing multiple test series and their further evaluation. Final application enables setting of test parameters and outputs a score, by which is possible to judge accelerator's performance in comparison among themselves.

Die vorliegende Arbeit ist Teil eines Forschungsprojekts zur Entwicklung eines neuartigen Systems zur zerstörungsfreien und bildgebenden Untersuchung von Luftfracht mittels Neutronen- und Gammastrahlung. Im Rahmen dieser Arbeit wurde eine Strahlungsquelle entwickelt, die optimal auf die Anwendung angepasst ist: Ein gepulster Deuteronenstrahl wird in einer Ionenquelle erzeugt und mittels eines niederenergetischen Strahltransportsystems zum Hauptbeschleuniger geführt. Dieser besteht aus einem Radiofrequenz Quadrupol (RFQ) mit einer finalen Energie von 6 MeV. Da für die Anwendung sehr kurze Pulse der Strahlung in der Größenordnung einiger Nanosekunden unabdingbar sind, musste eine neuartige Lösung zur Pulsung des Deuteronenstrahls gefunden werden. Eine große Herausforderung bestand hierbei im Zusammenspiel der kurzen Pulsdauer und hohen Pulsladung in Kombination mit der hohen Wiederholrate. Dieses wurde erreicht, indem ein spezielles Pulsungssystem innerhalb des Strahlentransportes zwischen Ionenquelle und RFQ eingefügt wurde. Dieses System enthält neben einem strahlablenkenden auch ein strahlbündelndes Element. Der Deuteronenstrahl wird hinter dem RFQ auf ein Target geführt, welches aus Borcarbid besteht. In dieser Arbeit wird das komplette physikalische Design der Strahlungsquelle diskutiert sowie Simulationen zum Pulsungssystem bzw. dem RFQ-Beschleuniger präsentiert. Weiterhin werden Proof-of-Principle Experimente beschrieben, die mithilfe eines Prototypen-Pulsungssystems entwickelt im Rahmen dieser Arbeit und gefertigt von der RI Research Instruments GmbH an einem speziell für diesen Zweck errichteten Teststands durchgeführt wurden. Außerdem wurden mehrere Experimente sowohl an der Beschleunigeranlage der Physikalisch- Technischen Bundesanstalt (PTB) Braunschweig als auch am RFQ Beschleuniger der Nuclear Energy Corporation of South Africa (NECSA) in Pelindaba durchgeführt, um das Target zu optimieren und das erzeugte Strahlungsfeld zu charakterisieren. / This thesis is part of a research project whose goal is to develop a novel, non-destructive imaging system to be employed for air freight security. The screening will be performed employing neutron- and gamma-radiation based techniques. One of the critical issues in this project was the absence of an adequate particle source. Thus, a new type of source was developed during this work. The new source consists of four main parts: A pulsed deuteron beam is formed in an ion source (IS) and is fed, via a matching low energy beam transport system (LEBT), into the main accelerator. The latter comprises a radio frequency quadrupole (RFQ) that produces a deuteron beam with a final energy of 6 MeV. Since pulsing of this beam in the regime of several nanoseconds is mandatory for the application, a novel solution had to be found to apply the required pulsing scheme, without undershoot the required beam charge per pulse. A major challenge in doing so was the combination of pulse length, high bunch charge as well as high repetition rate. This could be achieved by adding a pulsing system in between the LEBT section and RFQ: it consists of a beam-deflection, as well as a beam-bunching element. The deuteron beam is ultimately directed to a wobbling, plasma sprayed boron carbide (B4C) target. This work focuses on an entire physical design as well as simulation work of the pulsing system and RFQ. Furthermore, proof-of-principle experiments concerning a prototype of the pulsing system developed in the framework of this thesis and manufactured by RI Research Instruments GmbH could be performed at a test bench dedicated to this project. To round up the study, the suitability of the target and target reaction was demonstrated during multiple experiments performed at Physikalisch- Technische Bundesanstalt (PTB) at Braunschweig as well as the Nuclear Energy Corporation of South Africa (NECSA) in Pelindaba.

La crise financière de 2009 a ravivé le débat entre les classiques et les keynésiens concernant le rôle de la finance dans le cycle d’affaire. Cette thèse étudie les conséquences macroéconomiques des imperfections du marché de crédit ainsi que quantifie leur impact sur le marché de travail. L’interaction entre chômage et frictions financière passe par l’hypothèse que les postes vacants sont financés par des fonds externes qui sont plus couteux qu’un financement interne, de par de l’impact de l’asymétrie d’information sur le marché du crédit. Il est alors montré, à l’aide de simulation d’un modèle DSGE calibré sur données US., qu’un choc financier négatif, i.e. un choc qui augmente la prime de risque sur le marché du crédit ou un choc qui détériore le bilan des entrepreneurs, réduit de manière significative les capacités d’emprunt, et, par conséquent, la création d’emplois diminue spécialement. En outre, un choc d'incertitude engendre une augmentation du taux de chômage et rend cette augmentation plus persistante en période de crise. Ce résultat est confirmé par une évidence empirique qui consistait à estimer un modèle VAR bayésien, où des variables de marché de travail réelles et financières. / The crisis of 2009 raised the question whether the financial conditions matter for the business cycles and the propagation of shocks originating in the financial sphere. I tried to drive a fine analysis of this issue using micro-founded general equilibrium models. The modelling choice was backed by empirical motivations. In three essays, i study the impact of monetary and financial shocks on growth and labour market dynamics. First, an expansionary monetary policy eases credit conditions, raises risk tolerance and the quality of borrowers and generates a liquidity effect. The potency of the monetary policy and the size of the credit channel depend considerably on the degree of financial frictions in the credit market. Second, a restrictive monetary policy shock, an positive credit shock and a positive uncertainty shocks have similar effects on the economy: they plunge the economy in a recession, with output, job creations, and hours worked decreasing, while unemployment and job destructions increase. In all cases the interest rate spread increase, therefore indicating that financial conditions deteriorate, which is interpreted as a sign that financial frictions play a critical role in the propagation of these shocks. Third, the interaction between financial and labour market frictions does exist. The interplay between the two indeed plays a role in propagating the shocks. A shock to net worth, a credit shock and an uncertainty shock play a non-trivial role for the dynamics on the labour market.

Eine der wichtigsten nuklearen Prozesse stellt der Neutroneneinfang dar. In der kosmischen Nukleosynthese (s-Prozess) schwerer Elemente werden Kerne mit Massenzahlen größer als die von Eisen (A = 56) produziert, welche durch Kernfusion nicht produziert werden können. Dabei fängt ein Kern ein Neutron ein, wird durch die frei werdende Bindungsenergie angeregt und kann sich anschließend unter Aussenden von Photonen (Gamma-Quanten) wieder abregen. Aus der Abregung über Gammastrahlung können Rückschlüsse auf die Struktur des aktivierten Nuklids gezogen werden. Im Rahmen dieser Arbeit werden die ausgesendeten Photonen des angeregten Elements 78Se, welches durch Neutroneneinfang an 77Se am Reaktor des Instituts Laue-Langevin in Grenoble, Frankreich produziert wurde, näher untersucht. Dazu mussten zunächst Effi zienzkalibrierung und Addback-Korrekturen vorgenommen werden. Im Anschluss konnten mit Hilfe des EXILL-Multidetektoraufbaus Koinzidenzbeziehungen mehrerer aufeinander folgender Photonen untersucht und in einem Niveauschema zusammengefasst werden. Mit Hilfe der Winkelverteilung konnten diversen Zuständen Spins zugeordnet werden. Des Weiteren wurden die Ergebnisse einer Simulation von Gammakaskaden (DEX) und eines Photonenstreuungsexperiments am Elektronenbeschleuniger ELBE des HZDR mit den in Grenoble aufgenommenen experimentellen Daten verglichen.

The following thesis is a comparison study which was performed in cooperation with Sika Sverige AB. The project was to examine concrete’s behaviour while being subjected to different accelerators which is used to speed up the hardening process in young concrete. Sika provided the materials and the instructions for the tests that were made. The tests used where almost like the tests being performed at Sika’s laboratories but with some adjustments to the testing equipment. According to the results of the tests a clear difference between the different accelerators were found. The conclusion that the efficiency of the different accelerators were affected on several variables such as cement type, hardening age and hardening temperature were drawn. Because of the corona outbreak (2020) the tests could not be performed in Sikas laboratories. The tests were therefore carried out at a temporary laboratory without any direct supervision and some professional equipment could not be obtained which resulted in replacements with creative solutions. These changes affected the individual test results with high certainty but should not interfere with the conclusions on account that all test samples were subjected to the same circumstances.

La physique des particules élémentaires, aussi appelé physique des hautes énergies, est l'étude de l'infiniment petit, popularisée récemment par la découverte de nouvelles particules fondamentales permettant de consolider notre connaissance de la matière. Pour réaliser des mesures à une échelle aussi réduite, une méthode consiste à augmenter l’énergie des constituants de la matière, à l'aide d'accélérateur de particules, puis de les briser pour révéler leur constitution. Au-delà de l'intérêt en termes de physique expérimentale, réaliser des expériences de ce type est devenu une prouesse technologique grandissante avec les niveaux d’énergie atteints. La complexité de l’expérience CMS, cadre dans laquelle ce travail a été réalisé, donne une bonne mesure des défis technologiques relevés.<p>Afin d'affiner encore notre connaissance des processus mis en jeu lors collision de particules dans CMS, une mise à niveau du détecteur est prévue avant la fin de cette décennie. Certains sous-détecteurs actuellement installés, et notamment le spectromètre à muon dans la zone des bouchons, sont d’ores et déjà identifiés comme offrant des performances trop faibles pour l'augmentation du nombres d’événements prévu après cette mise à jour. Ce travail propose de réaliser une étude de faisabilité sur l'utilisation d'une technologie alternative pour ce sous-détecteur, notamment le Triple-GEM, pour combler ces limitations.<p>Une première partie de ce travail consiste en l'étude de cette nouvelle technologie de détecteur à gaz. Cependant, la mise en œuvre de cette technologie conduit à des modifications dans le système d'acquisition de données de CMS. La situation actuelle puis les implications d'un point de vue technique des modifications sont donc détaillées par la suite. Enfin, après avoir identifié les composants et les solutions permettant la collecte de résultats à l’échelle de l'ensemble du sous-détecteur, un système d'acquisition de données similaire a été réalisé et est décrit dans une dernière partie de ce travail. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished