Arbetet gjordes för att ta reda på vad forskningen säger om laborationernas roll i fysikundervisningen. Detta gjordes genom att jag läste flera olika forskningsrapporter, bland annat från en stor undersökning inom EU där ett försök gjordes att undersöka måluppfyllelsen i dagens fysikundervisning. Forskarna tog först reda på vilka mål lärare har med sin undervisning, och sedan togs reda på i vilken utsträckning olika typer av undervisning hjälper eleverna att nå dessa mål. Resultaten visar att det bästa sättet att nå de fem huvudmålen (Länka teori och praktik, lära sig att utföra experiment, lära sig vetenskapliga metoder, öka motivationen och undersöka elevernas kunskaper) är en blandning av undervisningsmetoder, där laborativa moment är en viktig del. Min egen undersökning visade på samma resultat. För att få eleverna att förändra sina alternativa begrepp, så att de stämmer bättre överens med de vetenskapliga, krävs något mer än en öppen laboration. Variation verkar vara nyckeln till god måluppfyllelse.

Modern physical experiments often demand advanced instrumentation based on advances in  technology. This work describes four instrumentation physics projects that are based on modern, high-capacity Field-Programmable Gate Arrays, making use of their versatility, programmability, high bandwidth communication interfaces and signal processing capabilities. In the first project, a jet-finding algorithm for the ATLAS detector at the LHC experiment at CERN was developed and implemented, and different verification methods were created to validate the functionality and reliability. The experiment uses a three level trigger system, where the first level uses custom FPGA-based hardware for analysis of collision events in real-time. The second project was an advanced timing and triggering distribution system for the new European X-Ray Free Electron Laser (XFEL) facility at DESY in Hamburg. XFEL will enable scientists to study nano structures on the atomic scale. Its laser pulses will have the strongest peak power in the world with extremely short duration and a high repetition rate, which will even allow filming of chemical reactions. The timing system uses modern FPGAs to distribute high-speed signals over optical fibers and to deliver clocks and triggers with high accuracy. The third project was a new data acquisition board based on high-speed ADCs combined with high-performance FPGAs, to process data from segmented Ge-detectors in real-time. The aim was to improve system performance by greatly oversampling and filtering the analog signals to achieve greater effective resolution. Finally, an innovative solution was developed to replace an aging system used at CERN and Stockholm University to test vital electronics in the Tile Calorimeters of the ATLAS detector system. The new system is entirely based on a commercial FPGA development board, where all necessary custom communication protocols were implemented in firmware to emulate obsolete hardware. / Inom området instrumenteringsfysik bedrivs forskning och utveckling av avancerade instrument, som används inom moderna fysikexperiment. Denna avhandling beskriver fyra projekt där programmerbara kretsar (FPGA) har nyckelfunktioner för att lösa krävande instrumenteringsuppgifter. Den första projektet beskriver utveckling och implementering av en algoritm för detektering av partikelskurar efter partikelkollisioner i LHC-experimentets ATLAS-detektor. Experimentet genererar 40 miljoner händelser per sekund, som måste analyseras i real-tid med hjälp av snabba parallella algoritmer. Resultatet avgör vilka händelser som är tillräckligt intressanta för fortsatt noggrannare analys. Den andra projektet beskriver utvecklingen av ett system som distribuerar klock- och trigger-signaler över ett 3 kilometers experimentområde med extrem precision, i den nya röntgenlaseracceleratorn XFEL vid DESY i Hamburg. Vid XFEL kommer man utforska nanostrukturer och till och med filma molekylers kemiska reaktioner. I den tredje projektet beskrivs utvecklingen av ett höghastighets datainsamlingssystem, för segmenterade Ge-detektorer. Genom att översampla signalen med hög hastighet kan man uppnå en bättre noggrannhet i mätningen än vad AD-omvandlarens egna upplösning medger. Detta leder i sin tur  till förbättrade systemprestanda. Slutligen beskrivs en innovativ lösning till ett test system för den elektronik, som Stockholms universitet har levererat till ATLAS detektorn. Det nya systemet ersätter det föregående testsystemet, som är baserad på föråldrade inte längre tillgängliga komponenter. Det nya systemet är dessutom också billigare eftersom det är baserat på ett standard FPGA utvecklingskort. / ATLAS experiment of the Large Hadron Collider experiment / European X-ray Free Electron Laser

Lic.-avh. (sammanfattning) Stockholm : Kungliga Tekniska högskolan, 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Kungliga Tekniska högskolan, 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Kungliga Tekniska högskolan, 2007. / Härtill 7 uppsatser.

Gamification -- bruket av spelelement i icke-spelsammanhang -- har visat sig vara ett effektivt sätt att skapa mer underhållande och engagerande användarupplevelser. Många tillämpningar av gamification förlitar sig på en begränsad delmängd av spelelement som poäng, emblem och resultatlistor -- tekniker som kritiserats för att inte vara representativa för vad som gör spel underhållande. Forskning inom psykologin indikerar att personer blir mest effektivt motiverade av faktorer som vädjar till deras personliga tillfredsställelse, såsom nöje, snarare än externa faktorer som belöning och priser. Detta arbete utforskar bruket av speldesignelement och relaterade 3D-teknologier i utvecklingen av ett verktyg avsett för att skapa och simulera fysikaliska modeller. Implementationen av ett sådant verktyg beskrivs med fokus på integrationen av speldesignelement vilka bidrar till en underhållande och engagerande upplevelse för användaren. En studie utförs för att validera effekten av bruket av spelelement på användarnas nöje när dessa interagerar med simulationsverktyget. Det observerades att genom att använda teman som användaren kan relatera till och som är kontextuellt passande för applikationen i fråga kan spelelement förstärka en njutbar användarupplevelse. / Gamification -- the use of game elements in non-game contexts -- has been shown to be an effective way of creating more enjoyable and engaging user experiences. Many applications of gamification rely on a limited subset of game elements such as points, badges and leaderboards -- techniques which have been criticised for not being representative of what makes games enjoyable. Research in psychology suggests that people are most effectively motivated by factors that appeal to their personal satisfaction, such as fun, rather than external factors such as rewards and prizes. This thesis explores the use of game design elements and related 3D technologies in the creation of a tool for the construction and simulation of physical models. The implementation of such a tool is described, focussing on the integration of game design elements that produce a fun and engaging experience for the user. A study is performed to determine the effects of the use of game elements on users’ enjoyment when interacting with the simulation tool. It was found that by appealing to themes users can relate to and which are contextually appropriate for the application, game elements can help promote an enjoyable user experience.

Doctor of Philosophy / We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and perturbations have vertical wavevectors only. Solutions are obtained at representative radial locations from the central protostar for different choices of the initial magnetic field strength, sources of ionisation, disc structure and configuration of the conductivity tensor. The MRI is active over a wide range of magnetic field strengths and fluid conditions in low conductivity discs. For the minimum-mass solar nebula model, incorporating cosmic ray and x-ray ionisation and assuming that charges are carried by ions and electrons only, perturbations grow at 1 AU for B < 8G. For a significant subset of these strengths (200mG < B < 5 G), the growth rate is of order the ideal MHD rate (0.75 Omega). Hall conductivity modifies the structure and growth rate of global unstable modes at 1 AU for all magnetic field strengths that support MRI. As a result, at this radius, modes obtained with a full conductivity tensor grow faster and are active over a more extended cross-section of the disc, than perturbations in the ambipolar diffusion limit. For relatively strong fields (e.g. B > 200 mG), ambipolar diffusion alters the envelope shapes of the unstable modes, which peak at an intermediate height, instead of being mostly flat as modes in the Hall limit are in this region of parameter space. Similarly, when cosmic rays are assumed to be excluded from the disc by the winds emitted by the magnetically active protostar, unstable modes grow at this radius for B < 2 G. For strong fields, perturbations exhibit a kink at the height where x-ray ionisation becomes active. Finally, for R = 5 AU (10 AU), unstable modes exist for B < 800 mG (B < 250 mG) and the maximum growth rate is close to the ideal-MHD rate for 20 mG < B < 500 mG (2 mG < B < 50 mG). Similarly, perturbations incorporating Hall conductivity have a higher wavenumber and grow faster than solutions in the ambipolar diffusion limit for B < 100 mG (B < 10 mG). Unstable modes grow even at the midplane for B > 100 mG (B ~ 1 mG), but for weaker fields, a small dead region exists. When a population of 0.1 um grains is assumed to be present, perturbations grow at 10 AU for B < 10 mG. We estimate that the figure for R = 1 AU would be of order 400 mG. We conclude that, despite the low magnetic coupling, the magnetic field is dynamically important for a large range of fluid conditions and field strengths in protostellar discs. An example of such magnetic activity is the generation of MRI unstable modes, which are supported at 1 AU for field strengths up to a few gauss. Hall diffusion largely determines the structure and growth rate of these perturbations for all studied radii. At radii of order 1 AU, in particular, it is crucial to incorporate the full conductivity tensor in the analysis of this instability, and more generally, in studies of the dynamics of astrophysical discs.

Doctor of Philosophy / We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and perturbations have vertical wavevectors only. Solutions are obtained at representative radial locations from the central protostar for different choices of the initial magnetic field strength, sources of ionisation, disc structure and configuration of the conductivity tensor. The MRI is active over a wide range of magnetic field strengths and fluid conditions in low conductivity discs. For the minimum-mass solar nebula model, incorporating cosmic ray and x-ray ionisation and assuming that charges are carried by ions and electrons only, perturbations grow at 1 AU for B < 8G. For a significant subset of these strengths (200mG < B < 5 G), the growth rate is of order the ideal MHD rate (0.75 Omega). Hall conductivity modifies the structure and growth rate of global unstable modes at 1 AU for all magnetic field strengths that support MRI. As a result, at this radius, modes obtained with a full conductivity tensor grow faster and are active over a more extended cross-section of the disc, than perturbations in the ambipolar diffusion limit. For relatively strong fields (e.g. B > 200 mG), ambipolar diffusion alters the envelope shapes of the unstable modes, which peak at an intermediate height, instead of being mostly flat as modes in the Hall limit are in this region of parameter space. Similarly, when cosmic rays are assumed to be excluded from the disc by the winds emitted by the magnetically active protostar, unstable modes grow at this radius for B < 2 G. For strong fields, perturbations exhibit a kink at the height where x-ray ionisation becomes active. Finally, for R = 5 AU (10 AU), unstable modes exist for B < 800 mG (B < 250 mG) and the maximum growth rate is close to the ideal-MHD rate for 20 mG < B < 500 mG (2 mG < B < 50 mG). Similarly, perturbations incorporating Hall conductivity have a higher wavenumber and grow faster than solutions in the ambipolar diffusion limit for B < 100 mG (B < 10 mG). Unstable modes grow even at the midplane for B > 100 mG (B ~ 1 mG), but for weaker fields, a small dead region exists. When a population of 0.1 um grains is assumed to be present, perturbations grow at 10 AU for B < 10 mG. We estimate that the figure for R = 1 AU would be of order 400 mG. We conclude that, despite the low magnetic coupling, the magnetic field is dynamically important for a large range of fluid conditions and field strengths in protostellar discs. An example of such magnetic activity is the generation of MRI unstable modes, which are supported at 1 AU for field strengths up to a few gauss. Hall diffusion largely determines the structure and growth rate of these perturbations for all studied radii. At radii of order 1 AU, in particular, it is crucial to incorporate the full conductivity tensor in the analysis of this instability, and more generally, in studies of the dynamics of astrophysical discs.

För att underlätta grafikers animationsarbete har det länge varit intressant att utforska olika fysikbaserade lösningar och göra dem effektiva. Detta arbetes mål har varit att undersöka olika villkorslösare för trasdocksfysik och fastställa vilken som hade bäst balans mellan tidseffektivitet och trovärdighet. Bakgrunden presenterar tidigare forskning som arbetet bygger på och går igenom viktiga begrepp inom trasdocksfysiksimulering relaterat till funktionalitet och trovärdighet. Olika scenarier och en benchmarker utvecklades för att testa trasdocksversionerna och kortare videoklipp skapades som observerades av respondenter för att avgöra versionernas trovärdighet. Resultatet från undersökningen visade inte på någon större skillnad för trovärdigheten av versionerna, men visade en större skillnad av tidseffektivitet mellan dem. Den sammantagna bedömningen blev att versionen med tre relaxationssteg, utan prioriteringsprocess av förskjutningar hade bäst balans. För framtida arbete är det intressant att studera hur väl versionerna presterar om de körs på GPU och att lägga till självkollision för trasdockan. / <p>Det finns övrigt digitalt material (t.ex. film-, bild- eller ljudfiler) eller modeller/artefakter tillhörande examensarbetet som ska skickas till arkivet.</p>

El Gran Colisionador de Hadrones (LHC) tiene previsto aumentar su luminosidad hasta siete veces su valor actual con el objetivo de ampliar su actual programa de física. Esta mejora se conoce con el nombre de High Luminosity LHC (HL-LHC) y está prevista para el año 2024-2026. El actual Inner Detector (ID) del detector de ALTAS será completamente reemplazado por uno nuevo para ajustarse a los rigurosos requisitos que impone el HL-LHC. Nuevos detectores de píxeles están siendo investigados para su utilización en todo el ID cuando el HL-LHC entre en operación. La utilización de sensores de píxeles tipo monolítico dentro del ID de ATLAS supondría una nueva era para los detectores de píxeles en física de altas energías debido a sus muchas ventajas con respecto a las tecnologías que se usan actualmente. Las principales ventajas son: mejor resolución espacial, menor densidad, mayor rendimiento, y menor coste. En este contexto, un nuevo tipo de sensor monolítico conocido como Depleted Monolithic Active Pixel Sensor on silicon-on-insulator ha sido investigado en esta tesis. El capítulo 1 describe el LHC, el experimento ATLAS, y las mejoras previstas para el HL-LHC. Este capítulo también describe los requerimientos y desafíos del futuro Inner Detector, al ser el subdetector más cercano al punto de interacción. El capítulo 2 describe la base de los detectores de partículas en física de altas energías. Este capítulo abarca la interacción de partículas con la materia, los conceptos básicos para la construcción de un detector de píxeles, y la resolución de momento transverso, vértice, y parámetro de impacto de un detector. El capítulo 3 describe los daños que la radiación produce en detectores de silicio, tanto en la electrónica como en el sensor, cuyo impacto es crucial en el rendimiento de los detectores especialmente para experimentos en el HL-LHC. El capítulo 4 revisa la evolución y tendencias en detectores de pixeles, abarcando desde los ya bien establecidos pixel híbridos, hasta los CMOS píxeles. La sección dedicada a los CMOS píxeles describe los diferentes tipos que se están considerando en ATLAS: High resistivity CMOS, high voltage CMOS, y monolíticos CMOS-on-SOI. Este ultimo compone el núcleo de estudio de esta tesis y es descrito en detalle. Los siguientes capítulos detallan el programa de caracterización y medidas realizado en el contexto de esta tesis. El capitulo 5 se centra en la caracterización del daño creado por la radiación en la electrónica hasta las dosis esperadas en el ID de ATLAS durante su operación en el HL-LHC. Las propiedades del detector, como son las corrientes de fuga, el cociente entre señal y ruido, la colección de carga y la profundidad de depleción, son descritas en el capitulo 6. El Capítulo 7 describe la caracterización de sensores monolíticos CMOS-on-SOI en un haz de piones, donde la colección de carga, el reparto de carga entre píxeles, la resolución espacial, y la eficiencia son discutidas. Este trabajo concluye con un resumen, con vistas al futuro de las tecnologías monolíticas CMOS-on-SOI en la física de altas energías. / A major upgrade of the Large Hadron Collider (LHC) called High Luminosity LHC (HL-LHC) is scheduled for 2024-2026. This will lead to an increase of the luminosity by seven times the current value and to the extension of the currently ongoing physics programme. A completely new Inner Detector for the ATLAS experiment needs to be developed to withstand the extremely harsh environment at the HL-LHC. New pixel detector concepts are being investigated as a possible candidate to the inner and outer layers of the HL-LHC ATLAS Inner Detector. The use of monolithic pixel sensors in the ATLAS Inner Tracker would lead to a new era of pixel detectors as a consequence of its many advantages with respect to the current technologies. The achievement of smaller spatial resolution, lower density, bigger production yield and throughput, and smaller budget cost are the main arguments to pursue this technology. In this context, a novel Depleted Monolithic Pixel Active Detector built on a thick film Silicon-On-Insulator has been fully investigated in this thesis. Chapter 1 introduces LHC and the ATLAS experiment as well as their foreseen scenarios at the HL-LHC upgrade. This naturally motivates the stringent requirements and challenges of the closest sub-detector to the interaction point, the Inner Detector. Chapter 2 describes the basis of a tracking detector for high energy physics applications, detailing the interactions of particles with matter to the formation of a pixel detector from a semiconductor material. Then the momentum, vertex, and impact parameter resolution of a tracking detector are calculated leading to a set of requirements for the detector design. Chapter 3 describes the radiation damage in silicon detectors whose impact to the detector performance is crucial specially for HL-LHC experiments. The radiation damage in the electronics and in the silicon bulk is treated. Chapter 4 revises the current developments and trends on pixel detectors from the well established hybrid pixel technologies to the commercial CMOS pixels. The commercial CMOS pixels section describes the current technologies being considered at ATLAS: high resistivity, high voltage CMOS (currently built as hybrid and as monolithic), and monolithic CMOS-on-SOI. The latter one composes the core of study of this thesis and is described in great detail. The final chapters are dedicated to the description of the validation programme performed to the CMOS-on-SOI technology, together with characterization methods used, measurements performed, and results analysis description. Chapter 5 focuses on the measurements performed to characterize the radiation hardness of the technology against the ionizing radiation expected in the HL-LHC ATLAS detector. The crucial charge collection properties to fulfil the ATLAS detector requirements were measured and are described in Chapter 6. These measurements include leakage current, signal-to-noise ratio, collected charge, and depletion depth on unirradiated and irradiated samples. Additionally, different techniques as radioactive sources, pion beams, and laser beams were used in order to calculate the depletion depth. Chapter 7 describes the characterization of the monolithic CMOS-on-SOI in a pion beam test. The measured charge collection, charge sharing, spatial resolution, and tracking efficiency are discussed. Within the summary, an outlook towards the future of depleted monolithic active pixel sensors on silicon-on-insulator technology for high energy physics is presented.