Automata theory, one of the main branches of theoretical computer science, established its roots in the middle of the 20th century. One of its most fundamental concepts is that of a finite automaton, a basic yet powerful model of computation. In essence, finite automata provide a method to finitely represent possibly infinite sets of strings. Such a set of strings is also called a language, and the languages which can be described by finite automata are known as regular languages. Owing to their versatility, regular languages have received a great deal of attention over the years. Other formalisms were shown to be expressively equivalent to finite automata, most notably regular grammars, regular expressions, and monadic second order (MSO) logic. To increase expressiveness, the fundamental idea underlying finite automata and regular languages was also extended to describe not only languages of strings, or words, but also of infinite words by Büchi and Muller, finite trees by Doner and Thatcher and Wright, infinite trees by Rabin, nested words by Alur and Madhusudan, and pictures by Blum and Hewitt, just to name a few examples. In a parallel line of development, Schützenberger introduced weighted automata which allow the description of quantitative properties of regular languages. In subsequent works, many of these descriptive formalisms and extensions were combined and their relationships investigated. For example, weighted regular expressions and weighted logics have been developed as well as regular expressions for trees and pictures, regular grammars for trees, pictures, and nested words, and logical characterizations for regular languages of trees, pictures, and nested words. In this work, we focus on two of these extensions and their relationship, namely weighted automata and weighted logics. Just as the classical Büchi-Elgot-Trakhtenbrot Theorem established the coincidence of regular languages with languages definable in monadic second order logic, weighted automata have been shown to be expressively equivalent to a specific fragment of a weighted monadic second order logic by Droste and Gastin. We explore several aspects of weighted automata and of this weighted logic. More precisely, the thesis considers the following topics. In the first part, we extend the classical Feferman-Vaught Theorem to the weighted setting. The Feferman-Vaught Theorem is one of the fundamental theorems in model theory. The theorem describes how the computation of the truth value of a first order sentence in a generalized product of relational structures can be reduced to the computation of truth values of first order sentences in the contributing structures and the evaluation of an MSO sentence in the index structure. The theorem itself has a long-standing history. It builds upon work of Mostowski, and was shown in subsequent works to hold true for MSO logic. Here, we show that under appropriate assumptions, the Feferman-Vaught Theorem also holds true for a weighted MSO logic with arbitrary commutative semirings as weight structure. In the second part, we lift four decidability results from max-plus word automata to max-plus tree automata. Max-plus word and tree automata are weighted automata over the max-plus semiring and assign real numbers to words or trees, respectively. We show that, like for max-plus word automata, the equivalence, unambiguity, and sequentiality problems are decidable for finitely ambiguous max-plus tree automata, and that the finite sequentiality problem is decidable for unambiguous max-plus tree automata. In the last part, we develop a logic which is expressively equivalent to quantitative monitor automata. Introduced very recently by Chatterjee, Henzinger, and Otop, quantitative monitor automata are an automaton model operating on infinite words. Quantitative monitor automata possess several interesting features. They are expressively equivalent to a subclass of nested weighted automata, an automaton model which for many valuation functions has decidable emptiness and universality problems. Also, quantitative monitor automata are more expressive than weighted Büchi-automata and their extension with valuation functions. We introduce a new logic which we call monitor logic and show that it is expressively equivalent to quantitative monitor automata.

This project study addressed the problem of the low percentage of a Mid-Atlantic university's radiography graduates passing their credentialing registry examination. The cohort had a 2014 pass rate of 83% while the majority of surrounding schools had pass rates of 100%. In order to become registered radiographers, graduates must be able to take what they have learned in their educational program and directly apply it to their professional skill set. The conceptual framework for the study was social constructivism, adapting and transforming what was new information to previous experiences and group activities. A qualitative case study research design was chosen, and interviews were conducted with 9 graduates from the 2014 radiography cohort. The interviews were recorded, transcribed, manually coded, and analyzed for emerging themes. Key results indicated the graduates needed to self-monitor, self-motivate, and self-propel to successfully pass their credentialing exam. A 3-day professional development plan for graduates was created based on the findings from the study. Passing the credentialing exam affects social change in that knowledge and education produces positive outcomes, and for allied health professionals, it produces optimum patient care. Social change is possible through education, which will enhance an individual's self-efficacy, thereby enriching the society and culture to which they contribute. This knowledge will support the local problem in that optimum performance for radiography graduates will be monitored for standards of excellence.

Fysisk aktivitet är en viktig del i alla människors liv och på senare år har flera tekniker utvecklats för att mäta just denna parameter. Detta har bidragit till en stor utveckling bland flertalet olika portabla tekniker, ofta i form av aktivitetsmätare, för att underlätta mätningar för alla inblandade. I samarbete med Energimetaboliska Laboratoriet (EML) på Akademiska sjukhuset i Uppsala studeras i denna studie kliniska aktivitetsmätare som används för monitorering av barn och unga vuxna. Syftet med studien är att få en djupare förståelse för de olika aktivitetsmätarnas modeller och fabrikat samt hur placeringar av dessa förhåller sig till varandra. Den parameter som jämfördes i studien var energiförbrukning som presenteras i kilokalorier (kcal). Jämförelsen gjordes mellan tre olika sorters aktivitetsmätare: ActiGraph GT9X Link som placerades runt handled, ActiGraph wGT3X-BT som placerades runt ankel samt Philips ActiCal som placerades runt både handled och ankel.Aktivitetsmätarna i denna studie mäter rörelse genom inbyggda accelerometrar. Accelerometrarna innehåller rörliga komponenter som förflyttas beroende på hur den som bär aktivitetsmätarna rör sig. Rörelserna omvandlas sedan till signaler som utlöser så kallade ”counts”. Counts är en storhet vars syfte är att registrera verkliga rörelser. För att erhålla counts så måste rörelsen antingen överstiga ett förutbestämt tröskelvärde eller låta de rörliga komponenterna genomföra en full cykel, exempelvis röra sig upp och sedan ned. Counts beräknas senare till bärarens energiförbrukning genom olika typer av algoritmer.I den empiriska studie som gjordes medverkade 13 deltagare som fick bära aktivitetsmätarna under ett helt dygn med start vid midnatt. Deltagarnas längd, vikt och ålder samlades in för att programmera aktivitetsmätarna enligt leverantörernas instruktioner. Extrahering av data skedde i tillverkarnas egna program ActiLife v6 13.1 och ActiCal v3.0 där beräkning av energiförbrukning skedde. När data var insamlad sammanställdes det i Microsoft Excel v16.72 för att enklare visualisera skillnader i energiförbrukning mellan deltagarna. Insamlade data jämfördes sedan statistiskt för att dra slutsatser om eventuella skillnader. Inga referensvärden användes i studien då aktivitetsmätarna endast jämfördes mot varandra.Resultaten visade tydliga skillnader mellan både fabrikat och placering beroende på vilka modeller som jämfördes. En relativt stor skillnad i energiförbrukning uppmättes mellan ActiGraph GT9X Link och wGT3X-BT där aktivitetsmätaren som placerades runt handleden uppmätte högre energiförbrukning för samtliga deltagare. En liknande skillnad uppmättes även vid jämförelse av ActiGraph GT9X Link och Phillips ActiCal placerad runt handled. Ingen statistisk skillnad kunde påvisas mellan ActiGraph wGT3X-BT och ActiCal, när de placerades runt ankeln. De båda placeringarna av ActiCal påvisade att dess tolkning av energiförbrukning ej skiljer sig åt särskilt mycket. / Background:Physical activity is a big part of everyone’s life and health. In recent years, the development of methods to monitor physical activity has increased drastically. Common parameters to measure are heart rate and respiratory rate but also physical movement. This is commonly measured with a wristwatch. Furthermore, there are several models made for clinical use, but the issue is that it is unknown how these activity monitors compare to each other. Aim:The aim of this study is to obtain a better understanding of the activity monitors ActiGraph GT9X Link, wGT3X-BT and Philips ActiCal for clinical use and how they compare to each other in regard to measuring energy expenditure. It also aims to investigate differences in monitor placement and how that affects the outcome. Method:An empirical study was made with 13 participants wearing the ActiGraph GT9X Link on the wrist, wGT3X-BT on the ankle and the Philips ActiCal on both places during a 24-hour period. The data collected was then analyzed to compare the monitors. Result:Differences were found between the two ActiGraph monitors as well as the ActiCal and ActiGraph GT9X Link placed on the wrist. The ActiGraph GT9X Link had overall the highest rate of energy expenditure. Furthermore, the ActiCal had the most similar results when comparing placement. Conclusion:The conclusion was that the ActiGraph GT9X Link is the most sensitive monitor and the ActiCal most reliable regarding placement.

<p>Sensor technology is evolving rapidly, offering new opportunities for environmental data collection. Yet, despite the large number of sensors now available, there is a lack of logging platforms that can be used to operate these sensors in situ. To address this shortfall, River Restoration Intelligence and Verification (RRIV) has developed an environmental data logger that meets the needs of the environmental sensing community. This platform has several advantages that reduce the time, effort, and technical know-how required to deploy environmental sensors. An extensive low-power mode is available, and hardware such as a real-time clock with an independent power source is incorporated. A driver system has been developed that allows users to incorporate sensors into the platform with minimal effort. RRIV loggers also include a command line interface that allows user to add or remove sensors, calibrate sensors, or configure deployments without the need for C/C++ programming, something that is not possible with out-of-the-box microcontrollers such as Arduino and ST Nucleo products. The technology incorporated into RRIV and how it is applied and deployed in the field is described. This includes a description of power consumption. Protocols and descriptions of case construction are also included. RRIV loggers configured to monitor carbon dioxide and methane are used to demonstrate how this platform is used in the field.</p>

The promulgation of revised standards for atmospheric fine particles (PM2.5) by the US EPA has sparked renewed interest in the ability to accurately measure and characterize suspended atmospheric particulate matter. Semi-volatile material (SVM), consisting of ammonium nitrate and semi-volatile organic material (SVOM), is not accurately measured by EPA accepted methods such as the Federal reference method (FRM) or Tapered Element Oscillating Microbalance (TEOM). However, SVM is often a major fraction of urban aerosols. Recent advances in atmospheric sampling instrumentation allowed for the semi-continuous characterization of urban PM2.5, including SVM. The Filter Dynamic Measurement System (FDMS) was shown to measure total PM2.5 mass including semi-volatile species. Validation of the FDMS was performed by comparison with the particle concentrator-Brigham Young University organic sampling system (PC-BOSS) and the real-time total ambient mass sampler (RAMS). Semi-continuous ambient particulate concentrations of sulfate, nitrate and ammonium ion were measured by a newly developed Dionex instrument which was field tested and validated for the first time in Fresno, CA. Either a modified Sunset Laboratory carbon monitor, collocated with a conventional Sunset carbon monitor employing a common inlet, or the newly developed dual-oven Sunset monitor allowed for the semi-continuous determination of both nonvolatile and semi-volatile organic material. This was the first attempt to characterize both nonvolatile and semi-volatile fractions of an urban aerosol in a semi-continuous manner using all semi-continuous instruments. A suite of instruments for semi-continuous PM2.5 monitoring was recommended including, an R&P FDMS for the measurement of PM2.5 mass, a dual-oven Sunset monitor for the measurement of nonvolatile and semi-volatile carbonaceous species, and a Dionex GP-IC for the measurement of inorganic species. A TEOM monitor is also recommended to measure nonvolatile PM2.5 mass. Using these instruments, semi-continuous mass closure was obtained for the first time during a study conducted in Riverside, CA. The advantage of using semi-continuous sampler data in the application of source apportionment was elucidated. Local aerosols are often impacted by short-term pollution episodes that cannot be temporally resolved using integrated samplers. One-h averaged data applied to source apportionment models was shown to increase the power of the model to predict sources, both primary and secondary, that exhibit diurnal short-term episodes.

NOx-sensorn är grundläggande i det moderna efterbehandlingssystemet och dess pålitlighet är avgörande för att kunna leva upp till rådande emissionslagkrav. Livslängden samt sensorns beteende i slutet av denna varierar betydligt. Om en NOx sensor med oberäkneligt beteende inte upptäcks av fordonets styrsystemet kan det orsaka omfattande verkstadsbesök eller i värsta fall brott mot emissionslagkrav. Examensarbetet involverar identifiering av olika sensorfellägen, tidiga tecken till dessa fellägen, förstå och identifiera förhållanden mellan olika sensorparametrar och analysera sensorbeteendet vid sensorlivslängdens slutskede. NOx sensorn är en relativt ny sensor och fordonsindustrin har ännu inte en fullständig förståelse för dess beteende. Litteraturstudien täcker olika fellägena så som fastnat värde, förskjutet värde, förstärkning av värdet, felaktiga svängningar samt långsam respons. Även effekterna av åldrande i NOx sensorn beskrivs. Litteraturstudien diskuterar också diagnoser av sensorer i allmänhet samt diagnoser specifikt för NOx sensorer. Uppsatsarbetet involverar också en experimentell studie där NOx sensorer utsätts för statiska och fluktuerande gasflöden i en motortestbädd. Fellägen i NOx sensorer kan observeras i parametrarna för NOx-värde och oxidationsnivå. I den version av NOx sensorn som användes observerades det också att parametrarna felaktig NOx och felaktig O2 visar samma felkod samtidigt. Dock är inte parametrarna för felaktig NOx och felaktig O2 relaterade till parametrarna för värmningsstatus, felaktig värmare och värmeelementets temperatur. Sensorns status gällande ogiltiga NOx-mätningar är större än eller lika med antalet ogiltiga O2-mätningar. Resultatet gäller framför allt sensormodell Continental 2.8 NOx sensorer. Även logik för en monitor gällande felaktiga svängningar utvecklas baserat på standardavvikelse och NOx statusparametern för ogiltig mätning. / The NOx sensor is essential in the modern after-treatment system and the reliability of the sensor is crucial for any emission-based legislation. The life span of a sensor varies a lot as well as the behaviour previous to its end of life. If a NOx sensor with erratic behaviour is not discovered by the control system it may cause extensive workshop effort or in worst case exceed legal requirements. The thesis work involves identifying different sensor failure modes, precursors to these failure modes, understanding and identifying relationships between different sensor parameters, and analysing the sensor behaviour especially towards the end of life. The NOx sensor is a relatively new sensor and the vehicle industry does not yet have a complete understanding of its behaviour. The literature study covers the different failure modes namely stuck, offset, gain, oscillations, and slow response and their causes along with the effects of ageing in NOx sensors. It also discusses the diagnosis of faulty sensors in general and faulty NOx sensors. The thesis work also involves an experimental study where the NOx sensors are subjected to static and transient gas flow tests in an engine testbed. Failure modes in NOx sensors are observable in NOx concentration and actual oxidation measurement parameters. It was also observed in the version of the NOx sensor used that Error NOx and Error O2 parameters show the same fault code at the same time. Although, the Error NOx and Error O2 parameters are not related to the heater parameters, Heater status, Error heater, and Temperature of heating element. The number of invalid flags set in NOx status is greater than or equal to the number of invalid flags in O2 status. The mentioned parameters are concerning Continental 2.8 NOx sensors. The logic for the oscillatory fault monitor is developed based on standard deviation and an invalid flag check on the NOx status parameter.

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]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34327

[EN] The Compact Linear Collider (CLIC) is an electron-positron collider conceived for the study of High-Energy Physics in the TeV center of mass energy region, is based on a two-beam operation principle: instead of using active elements (klystrons), the necessary RF power to accelerate the Main Beam (MB) is obtained from the deceleration of a high-current, moderate energy Drive Beam (DB) in the so-called Power Extraction and Transfer Structures (PETS). These structures emit an RF signal of about 130 MW power at 12 GHz. As this frequency is above the cut-o ff frequency of the fundamental mode for the specified beam pipe dimensions (7.6 GHz), the inference propagates from the PETS to the neighboring devices, including the Beam Position Monitors (BPM). According to the CLIC Conceptual Design Report (CDR), an ef ficient beam position monitoring system for the CLIC DB decelerator needs to meet the following requirements: - It should be as simple and economic as possible, as 41580 units are required, amounting to 75% of all CLIC BPMs. - The signal processing scheme should not be a ffected by the PETS interference. This rules out processing the signals at the beam bunching frequency (12 GHz). - The resulting position signal should detect changes in the beam position whose duration is 10 ns or longer. - The required spatial resolution is 2 um for a 23 mm diameter vacuum pipe. - Wide dynamic range: the electronic acquisition system must be able to process signals with extreme levels, induced by either very high (100 A) or very low (3 A) current beams. This PhD thesis describes the electromagnetic and mechanical design of the first prototype BPM developed for the CLIC Drive Beam and its characterization tests in laboratory and with beam. The first two chapters introduce the CLIC project and review the state-of-the-art beam position monitoring techniques. Chapter 3 presents the design of the BPM. The stripline technology has been selected, as it is the only one among the most commonly used BPM techniques to present a suitable frequency response to filter out the RF interference caused by the PETS. Choosing an appropriate length for the electrodes, it is possible to tune one the periodic notches in the stripline frequency response to 12 GHz. The influence of di erent electromagnetic and geometrical aspects is also studied, such as beam coupling impedance or the ratio between longitudinal and transverse dimensions. The design of the electronic acquisition system is presented in Chapter 4, considering the project requirements in terms of resolution (2 u m), accuracy (20 um) and time resolution (10 ns). Due to the high amount of units required, the number of electronics components has been minimized. As the designed signal processing scheme is based on charge integration, it can be adapted to di erent stripline pick-ups by simply modifying the attenuator settings according to the required output signal levels. The laboratory characterization tests of the prototype stripline BPM, in the low and the high frequency ranges, performed with a thin wire and a coaxial waveguide, respectively, are described in Chapter 5. The measurement results are compared with the theoretical estimation and the electromagnetic field simulations. In addition, the high-frequency test reveals that the first prototype stripline BPM does not provide su cient suppression of the 12 GHz PETS RF interference. An additional study proposed several modifications and guidelines for a second prototype stripline BPM. Finally, Chapter 6 presents the beam tests of the prototype stripline BPM at the CLIC Test Facility 3 (CTF3) in the Test Beam Line (TBL), a scaled version of the CLIC Drive Beam decelerator. Two types of tests were performed: linearity/sensivity and resolution. These results are compared to the ones in the laboratory characterization tests. An upper bound of the resolution is estimated performing a Singular Value Decomposition (SVD) analysis. / [ES] El Colisionador Lineal Compacto (Compact Linear Collider, CLIC), un colisionador de electrones y positrones concebido en el CERN para el estudio de la Física de Altas Energías en la región de los TeV, se basa en un principio de funcionamiento de doble haz: en lugar de emplear elementos activos (klystrons) para proporcionar la potencia RF requerida para acelerar el haz principal (Main Beam, MB), ésta se obtiene de la deceleración de un haz secundario (Drive Beam, DB), de alta corriente y energía moderada, en las llamadas estructuras de extracción y transferencia de potencia (Power Extraction and Transfer Structures, PETS). Estas estructuras emiten una señal interferente RF de más de 130 MW de potencia a 12 GHz, que, por estar localizada en una frecuencia superior a la de corte del modo fundamental en el tubo de vacío del haz (7.6 GHz), se propaga por éste hacia los dispositivos adyacentes, entre los cuales se encuentran los sistemas de monitorización de la posición (Beam Position Monitor, BPM). De acuerdo con el informe conceptual de diseño de CLIC (Conceptual Design Report, CDR) , un sistema eficiente de monitorización de la posición del haz en el decelerador del haz secundario deberá cumplir los siguientes requisitos: - Debe ser lo más sencillo y económico posible, ya que se precisan 41580 unidades: el 75% de todos los BPMs de CLIC. - El procesado de señal en el sistema de adquisición deberá ser inmune a la interferencia generada en las PETS. Esto excluye la solución habitual de procesar las señales del BPM a la frecuencia de pulsado del haz (12 GHz). - La señal de posición resultante del procesado debe ser capaz de detectar cambios en la posición del haz de duración igual o mayor a 10 ns (resolución temporal). - La resolución espacial requerida es de 2 um para un tubo de vacío de 23 mm de diámetro, con una calibración precisa. - Amplio rango dinámico: el sistema electrónico de adquisición del BPM debe poder resistir los altos valores de señal provocados por los casos de desviación extrema del haz nominal (se contempla una desviación máxima de la mitad del radio del tubo), así como detectar las señales inducidas por las configuraciones de haz con menor carga de todas las previstas, cuyos niveles serán muy débiles. / [CA] El Col·lisionador Lineal Compacte (Compact Linear Collider, CLIC), un col·lisionador d'electrons i positrons concebut per l'estudi de la Física d'Altes Energies a la regió dels TeV (energía del centre de massa), es basa en un principi de funcionament de doble feix:en lloc de fer servir elements actius (klystrons) per proporcionar la potència RF requerida per accelerar el feix principal (Main Beam, MB), aquesta s'obtè de la desacceleració d'un feix secundari (Drive Beam, DB), d'alt corrent i energia moderada, a les anomenades estructures d'extracció i transferència de potència (Power Extraction and Transfer Structures, PETS). Aquestes estructures emeten una senyal interferent RF de més de 130 MW de potència a 12 GHz, que, pel fet d'estar localitzada a una freqüència superior a la de tall del mode fonamental al tub de buit del feix (7.6 GHz), es propaga a través d'aquest fins els dispositius adjacents, entre els quals trobem els sistemes de monitorització de la posició (Beam Position Monitor, BPM). D'acord amb l'informe conceptual de disseny de CLIC (Conceptual Design Report, CDR), un sistema eficient de monitorització de la posició del feix al desaccelerador del feix secundari haurà de complir els següents requisits: ¿ - Ha de ser el més senzill i econòmic possible, ja que es necessiten 41580 unitats: el 75% de tots els BPMs de CLIC. ¿ - El processat de la senyal al sistema d'adquisició haurà de ser inmune a la interferència generada als PETS. Això exclou la solució habitual de processar les senyals del BPM a la freqüència de pulsacions del feix (12 GHz). ¿- La senyal de posició resultant del processat ha de ser capaç de detectar canvis a la posició del feix de durada igual o més gran que 10 ns (resolució temporal). ¿- La resolució espaial necessària és de 2 um per a un tub de buit de 23 mm de diàmetre. ¿- Ampli rang dinàmic: el sistema electrònic d'adquisició del BPM ha de poder processar senyals amb nivells extrems, induïdes per feixos de molt alt (100 A) i molt baix (3 A) corrent. / Benot Morell, A. (2016). Beam position monitoring in the clic drive beam decelerator using stripline technology [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64067

L’exploration d’une nouvelle physique à l’échelle d’énergie des « Tera electron Volt » (TeV) nécessite de collisionner des leptons dans de grands accélérateurs linéaires à grande luminosité. Ces collisionneurs linéaires requiert une taille de faisceau à l’echelle nanométrique au Point d’Interaction (IP).Parmi les multiples effets participant à la degradation de la luminosité, la correction de la chromaticité, l’effet du rayonnement synchrotronique et la correction des erreurs dans la ligne sont parmi les trois effets à maîtriser afin de réduire la taille du faisceau dans la Section Finale de Focalisation (FFS).Cette these propose un nouveau schéma de correction de la chromaticitè que l’on appelera “non-entrelacé”, appliqué ici au projet CLIC. Lors de l’implementation de cette nouvelle methode, il a été mis en evidence que le probléme principal est la dispersion de deuxième ordre au Doublet Final (FD), qui traverse un sextupole utilisé pour annuler les composantes géometriques restantes.L’effet du rayonnement peut être evalué par méthode de tracking des particules ou par des approximations analytiques. Afin d’inclure ces effets du rayonnement et les paramétres optiques de la ligne pendant la conception et le processus d’optimisation, l’effet Oide et le rayonnement dû aux aimants dipolaires ont été etudiés.Le résultat analytique du rayonnement synchrotronique dans les aimants dipolaires fut generalisé dans les cas avec alpha et dispersion non-nulles à l’IP. Cette généralisation est utilisée pour améliorer le code de simulation PLACET.Le rayonnement dans les aimants quadripolaires finaux imposent une limite à la taille verticale minimale du faiceau, connu comme l’effet Oide. Celui-ci est uniquement important à 3 TeV, donc deux possibilités sont explorées pour atténuer sa contribution dans la taille du faisceau : doubler la longueur et réduire le gradient du dernièr quadripole (QD0), ou integrer une paire d’aimants octupolaires, un en amont et un en aval du QD0.Une partie des exigences du FFS pour les nouveaux collisionneurs linéaire à leptons est testée expérimentalement dans l’« Accelerator Test Facility » (ATF). La réduction de la taille du faisceau d’électrons en utilisant le schéma local de correction de la chromaticité est explorée dans une extension de la ligne originale, appellé ATF2, oú deux buts furent fixés : atteindre 37 nm de taille verticale du faisceau à l’IP, et stabiliser de l’ordre du nanomètre la position verticale du faisceau à l’IP. Depuis 2014, une taille de 44 nm avec un nombre de particules d’environ 0.1 × 10^10 par paquet est atteint de manière regulière.Des cavités radio-frequence seront utilisées pour la stabilisation du faisceau, et également pour détecter le déplacement/les fluctuations du faisceau au dehors la marge tolerable pour le systéme de mesure, ainsi que des erreurs non detectées dans l’optique.Un set de trois cavités furent installées et sont utilisées pour mesurer la trajectoire du faiceau dans la région de l’IP, fournissant ainsi des informations pour reconstruire la position et l’angle à l’IP. Les specifications pour l’optique nominale d’ATF2, i.e. 1 nm de résolution sur 10 μm de gamme dynamique à un nombre de particules de 1.0 × 10^10 par paquet, n’ont pas encore été atteint.La meilleur résolution atteinte jusqu’ici correspond à 50 nm pour 0.4 × 10^10 particules par paquet, où le bruit de l’éléctronique impose une limite de 10 nm par cavité sur la résolution. La gamme dynamique est de 10 μm à 0.4 × 10^10 particules par paquet et 10 dB d’attenuation du signal des cavités, nécéssitant de mettre l’électronique à niveau. Le test du système d’asservissement pour stabiliser le faisceau a atteint une réduction de la fluctuation jusqu’a 67 nm, compatible avec la résolution des cavités. / The exploration of new physics in the “Tera electron-Volt” (TeV) scale with precision measurements requires lepton colliders providing high luminosities to obtain enough statistics for the particle interaction analysis. In order to achieve design luminosity values, linear colliders feature nanometer beam spot sizes at the Interaction Point (IP).Three main issues to achieve the beam size demagnification in the Final Focus Section (FFS) of the accelerator are the chromaticity correction, the synchrotron radiation effects and the correction of the lattice errors.This thesis considers two aspects for linear colliders: push the limits of linear colliders design, in particular the chromaticity correction and the radiation effects at 3 TeV, and the instrumentation and experimental work on beam stabilization in a test facility.A new chromaticity correction scheme, called non-interleaved, is proposed to the local and non-local chromaticity corrections for CLIC. This lattice is designed and diagnosed, where the main issue in the current state of lattice design is the non-zero second order dispersion in the Final Doublet (FD) region where a strong sextupole is used to correct the remaining geometrical components.The radiation effect can be evaluated by tracking particles through the lattice or by analytical approximations during the design stage of the lattices. In order to include both, radiation and optic parameters, during the design optimization process, two particular radiation phenomena are reviewed: the Oide effect and the radiation caused by bending magnets .The analytical result of the radiation in bending magnets in was generalized to the case with non-zero alpha and non-zero dispersion at the IP, required during the design and luminosity optimization process. The closed solution for one dipole and one dipole with a drift is compared with the tracking code PLACET, resulting in the improvement of the tracking code results.The Oide effect sets a limit on the vertical beamsize due to the radiation in the final quadrupole. Only for CLIC 3 TeV this limit is significant, therefore two possibilities are explored to mitigate its contribution to beam size: double the length and reduce the QD0 gradient, or the integration of a pair of octupoles before and after QD0.Part of the requirements of the FFS for new linear accelerators are tested in The Accelerator Test Facility (ATF). The beam size reduction using the local chromaticity correction is explored by an extension of the original design, called ATF2 with two goals: achieve 37 nm of vertical beam size at the IP, and the stabilization of the IP beam position at the level of few nanometres. Since 2014 beam size of 44 nm are achieved as a regular basis at charges of about 0.1 × 10^10 particules per bunch.A set of three cavities (IPA, IPB and IPC), two upstream and one downstream of the nominal IP and on top of separate blocks of piezo-electric movers, were installed and are used to measure the beam trajectory in the IP region, thus providing enough information to reconstruct the bunch position and angle at the IP. These will be used to for beam stabilization and could detect beam drift/jitter beyond the tolerable margin and undetected optics mismatch affecting the beam size measurements. The specifications required of 1 nm resolution over 10 μm dynamic range at 1.0 × 10 10 particules per bunch with the ATF2 nominal optics have not been yet achieved.The minimum resolution achieved is just below 50 nm at 0.4 × 10^10 particules per bunch with a set of electronics impossing a noise limit on resolution of 10 nm per cavity. The dynamic range is 10 μm at 10 dB attenuation and 0.4 × 10^10 particules per bunch, indicating the need to upgrade theelectronics. The integration to the ATF tuning instruments is ongoing. Nonetheless, feedback has been tested resulting in reduction of beam jitterdown to 67 nm, compatible with resolution.

This Ph.D. thesis deals with problems about voltage dips and short voltage interruptions, generally named as voltage events, which origin in power supply networks and have a negative influence for all connected electric appliances. In this thesis single phase appliances are considered. These problems closely relate with area of electromagnetic compatibility which solve all questions about correct operation of different types of electric appliances during electromagnetic disturbances impact. Voltage events are ones of the many types of electromagnetic disturbances. The connection between disturbance sources and sensitive electric appliances is created by power supply lines. The immunity of electric appliances to voltage dips and short interruptions is currently tested via voltage dips with strictly defined parameters which are intended by class of electromagnetic environment in which the usage of electric appliance is recommended. During immunity tests the rectangular shape of voltage dips is preferred. The main descriptive parameters of testing voltage events are the residual voltage and the event time duration. But voltage dips and short interruptions defined by this way do not closely relate with parameters of real voltage dips and interruptions occurred in public supply system where parameters of voltage dips are variable. Moreover in the power supply system there are many of others voltage parameters which can have a significant influence to immunity level of connected electric appliances. This Ph.D. thesis also deals with finding more voltage event parameters. Although the voltage events occurrence in the power supply system is not limited and voltage events are considered only as informative voltage parameter it is important to monitor voltage events occurrence. The monitoring device has to be able to operate for ling time period and it has to detect parameters of voltage events with adequate accuracy. The accuracy of detected event parameters and the detection delay depends on the detection algorithm characteristics. That is why the part of this thesis relates with a comparison of several detection algorithms and their abilities to correct detection of voltage event parameters. The main purpose of this thesis is the proposal of connection between classification of voltage dips and short interruptions occurred in power supply system with the classification of electric appliances immunity to these voltage events. On the base of many of provided electric appliances immunity tests and also on the base of long time period voltage events monitoring the special compatibility levels are proposed in this thesis. The observation of proposed compatibility levels will bring the increasing level of reliable operation of all connected electric appliances.