Ce travail tire partie de deux aspects de la diffusion elastique: retrodiffusion Rutherford ou non de particules alpha pour l'etude de la stoechiometre de couches minces complexes et production de noyaux de recul sous bombardement d'ions argon energetiques (16-20 MeV) pour l'analyse de surface d'elements legers comme oxygene azote et carbone. La premiere partie traite des conditions d'analyse de couches Ti$_(n-x)$Nb$_x$O$_2$ et Ti$_(l-x)$V$_x$O_$2$ dont la composition depend des parametres du depot par pulverisation cathodique H.F. de melange de poudres d'oxydes. On a determine en premier lieu les conditions d'analyse de ces couches avec la meilleure precision possible: dans les cas les plus favorables la concentration d'oxygene et le rapport des metaux sont connus a mieux de 5%. En ce qui concerne les resultats proprement dits nous montrons que pour les meilleures conditions de depot (vide residuel prepulverisation) le rapport O/(M+Ti) peut etre ajuste a 2 $\pm$ 0.1 sur toute la gamme de concentration cible. L'evolution des rapports Nb/(Nb+Ti) et V/(V+Ti) n'est pas identique a ceux des cilbes avec des ecarts dont nous tentons d'interpreter la signification. Dans la seconde partie traitant de la detection en temps de vol des noyaux de recule nous justifions le choix de nos parametres experimentaux par une etude detaillee de leur influence sur les performances analytiques. Malgre la serieuse limitation de la dispersion angulaire, la resolution en profondeur varie typiquement de 2 a 5 nm pour oxygene et carbone suivant qu'on s'adresse a une matrice de Z moyen (Si) ou eleve (Ta). L'apport d'une discrimination en energie a pour effet d'optimaliser les profondeurs analysables et d'eviter les interferences (C, N et O analysables sur 70 nm). Cette discrimination permet aussi d'abaisser les limites de detection (jusqu'a 10${13}$ at/cm$2$) par reduction du bruit de fond. Les limitations actuelles et les ameliorations possibles sont presentees a partir d'exemples d'analyse de surface.

An intra-pulse Interaction Point fast feedback system (IPFB) has been designed for the Next Linear Collider (NLC), to correct relative beam-beam misalignments at the Interaction Point (IP). This system will utilise the large beam-beam kick that results from the beam-beam interaction and apply a rapid correction to the beam misalignment at the IP within a single bunch train. A detailed examination of the IPFB system is given, including a discussion of the necessary electronics, and the results of extensive simulations based on the IPFB concept for fast beam correction are presented. A recovery of the nominal luminosity of the NLC is predicted well within the NLC bunch train of 266 ns. The FONT experiment - Feedback On Nanosecond Timescales - was proposed as a direct test of the IPFB concept and was realised at the NLC Test Accelerator at SLAC. As part of FONT, a novel X-band BPM was designed and tested at the NLCTA. The results of these tests with the NLCTA short and long-pulse beam are presented, demonstrating a linear response to the position of the 180 ns long-pulse beam: measurements show a time constant of ~1.5 ns and a precision of better than 20 microns. A novel BPM processor for use at X-band, making use of the difference-over-sum processing technique, is also presented in detail, with results given for both short and long-pulse beams. The FONT design concepts and modification of the IPFB system for use at the NLCTA are described. The design of a fast charge normalisation circuit, to process the difference and sum signals produced by the BPM processor, forming part of the FONT feedback circuit, is detailed extensively. Bench tests of the feedback electronics demonstrate the effectiveness of the normalisation and feedback stages, for which a signal latency of 11 ns was measured. These bench tests also show the correct operation of the normalisation and feedback principles. Finally, the results of a full beam test of the FONT system are presented, during which a system latency of 70 ns was measured. These rigorous tests establish the soundness of the IPFB scheme and show correction of a mis-steered bunch train within the full NLCTA pulse length of 180 ns.

O Laboratório do Acelerador Linear (LAL) do Instituto de Física da Universidade de São Paulo está construindo um acelerador de elétrons do tipo Mícrotron. O acelerador possui dois estágios de aceleração: o Mícrotron booster e o Mícrotron Principal. Atualmente, o sistema injetor do acelerador, que é um acelerador linear, dispõe de um feixe de elétrons de 1,9 MeV. Este feixe será inserido no primeiro estágio de aceleração, o Mícrotron booster, que já está construído e será testado em breve. Sua função é elevar a energia do feixe para 5 MeV. O objetivo deste trabalho é o de otimizar os parâmetros de operação do Mícrotron booster por meio de simulação. Também tivemos como objetivo estudar a viabilidade da adaptação do projeto original, com feixe de entrada de 1,765 MeV, para um feixe de entrada de 1,9 MeV. Tendo como foco principal encontrar a admitância do acelerador, foram desenvolvidas algumas rotinas de simulação. A admitância do Mícrotron booster para um feixe de 1,765 MeV foi calculada em 3,08 pi mm.mrad, 0,58 pi mm.mrad e 0,38 pi keV.rad para os espaços de fase horizontal, vertical e longitudinal, respectivamente. Para o feixe de 1,9 MeV, uma condição de aceleração foi encontrada e os valores de admitância foram 3,65 pi mm.mrad, 0,62 pi mm.mrad e 0,77 pi keV.rad para os mesmos espaços de fase. Dados de caracterizações do feixe, realizados em trabalhos anteriores foram utilizados para determinar a configuração das lentes quadrupolares responsáveis pela inserção do feixe no acelerador. Tais simulações darão suporte ao início de operação do Mícrotron booster, auxiliando na determinação dos parâmetros iniciais de operação e otimização dos parâmetros finais. / The Laboratório do Acelerador Linear is building a racetrack microtron electron accelerator. It has two acceleration stages: the booster and the main microtron. The injection system has already been commissioned and is delivering a 1.9-MeV continuous wave beam. This beam will be injected in the booster stage, which is ready to be commissioned, and should increase the energy to 5 MeV. The aim of this work is to optimize the operation parameters of the booster stage by means of simulation tools. We also studied the feasibility of injecting the 1.9 MeV beam in the booster, which has been designed to operate with a 1.765 MeV beam. Some simulation routines had to be developed in order to determine the admittance of the booster stage. For the 1.765 MeV beam the admittances were determined to be 3.08 pi mm.mrad, 0.58 pi mm.mrad, and 0.38 pi keV.rad for the transverse horizontal, transverse vertical, and longitudinal phase spaces, respectively. For the 1.9 MeV injection beam we were able to find a viable acceleration condition, with slightly better admittances: 3.65 pi mm.mrad, 0.62 pi mm.mrad, and 0.77 pi keV.rad, for the same phase spaces cited above. The injection beam has been characterized previously, and the available data were used, in the simulation codes, to match the transverse beam emittances of the injector to the transverse beam admittances of the booster. The phase space manipulations were accomplished by tuning a quadrupole triplet placed before the booster entrance. These simulations are intended as a supporting tool for the commissioning of the booster stage, helping the experimental determination of the working parameters and their optimization.

The advantages of contemporary particle injectors are high bunch charges and good beam quality in the case of normal conducting RF guns and increased repetition rates in the one of DC injectors. The technological edge of the concept of superconducting radio frequency injectors is to combine the strengths of both these sides. As many future accelerator concepts, such as energy recovery linacs, high power free electron lasers and certain collider designs, demand particle sources with high bunch charges and high repetition rates combined, applying the superconductivity of the accelerator modules to the injector itself is the next logical step. However, emittance compensation — the cornerstone for high beam quality — in case of a superconducting injector is much more challenging than in the normal conducting one. The use of simple electromagnets generating a solenoid field around the gun’s resonator interferes with its superconducting state. Hence, it requires novel and sophisticated techniques to maintain the high energy gain inside the gun cavity, while at the same time alleviating the detrimental fast transverse emittance growth of the bunch. In the case of the ELBE accelerator at the Helmholtz-Zentrum Dresden-Rossendorf, a superconducting electron accelerator provides beam for several independent beamlines in continuous wave mode. The applications include IR to THz free electron lasers, neutron and positron generation, to Thompson backscattering with an inhouse TW laser, and hence, call for a flexible CW injector. Therefore, the development of a 3.5 cell superconducting electron gun was initiated in 1997. The focus of this thesis lies on three approaches of transverse emittance compensation for this photoinjector: RF focusing, the installation of a superconducting solenoid close to the cavity’s exit, and the introduction of a transverse electrical mode of the RF field in the resonator. All three methods are described in theory, examined by numerical simulation, and experimentally reviewed in the particular case of the ELBE SRF Gun II at HZDR and a copy of its niobium resonator at Thomas Jefferson National Laboratory, Newport News, VA, USA.

This project has investigated the muon background of the SHiP experiment to determine whether it can boost the experiment sensitivity to visible Dark Photon decay. Using Fermi-Weizsäcker-Williams approximation to muon scattering we found the probability of muons generating massive photons, using Bremsstrahlung and direct lepton pair production as an estimation of the frequency of muon EM-interactions. In this work we only considered muons with momenta above 10 GeV/c. The number of visible Dark Photon decays was calculated for a range of the coupling constant and photon mass. The resulting range that promised visible decay has already been excluded by previous experiments, but the method could be used to further investigate enhanced production of Dark Photons from muons and electrons, and possibly also production of Axion-like particles. The work could also be used to estimate sensitivities of other experiments using muons.

This thesis attempts to develop a conversion algorithm between local coordinates in constituent detector modules and global coordinates encompassing the whole detector structure in a generic detector. The thesis is a part of preparatory work for studying the Hough Transform as a means of track reconstruction in the level-1 hardware trigger in the upgraded trigger and data acquisition (TDAQ) system in the phase 2 upgrade of the ATLAS detector at CERN. The upgrades being made are to withstand much more extreme conditions that come with the high-Luminosity Large Hadron Collider (HL-LHC). Two algorithms have been made and then implemented in Python scripts to test their feasibility and to compare them against each-other. The Rotation algorithm uses several rotations to correctly place the local coordinates in the global system. The second, the Shear algorithm, simplifies the process into two shears and one rotation, using the small angle approximation. Both algorithms need to be extended to work with more parts of the detector to be considered complete. Despite having lower maximum precision the second algorithm is considered the most promising attempt, since it is much less sensitive to the truncation error that results from working in an integer environment, which is a requirement for use in FPGAs. / I denna uppsats görs ett försök att skapa en omvandlingsalgoritm mellan lokala koordinater i konstituerande detektormoduler och globala koordinater i hela detektorstrukturen för en generisk detektor. Uppsatsen är en del i förberedande arbete för att undersöka hur Houghtransformen kan användas för spårrekonstruktion i den hårdvarubaserade level-1 triggern i det uppgraderade trigger- och datainsamlingssystemet (TDAQ) i fas två-uppgraderingen av ATLAS detektorn vid CERN. Uppgraderingarna som görs är för att kunna utstå de mycket mer extrema förhållanden som medförs av högluminositetsuppgraderingen av Large Hadron Collider (HL-LHC). Två algoritmer har skapats och implementerats i Pythonskript för att testa genomförbarhet och för att jämföra med varandra. Rotationsalgoritmen använder ett antal rotationer för att korrekt placera ut de lokala koordinaterna i det globala systemet. Den andra, Skjuvalgortimen, förenklar processen till två skjuvningar och en rotation med hjälp av liten vinkel-approximationen. Båda algoritmerna behöver utökas för att fungera för fler delar av detektorn för att anses kompletta. Trots lägre maximal precision bedöms den andra algoritmen vara det mest lovande försöket, eftersom den är mycket mindre känslig för trunkeringsfelet som kommer av att arbeta i en heltalsmiljö, som är ett krav för FPGA-implementationen.

The advantages of contemporary particle injectors are high bunch charges and good beam quality in the case of normal conducting RF guns and increased repetition rates in the one of DC injectors. The technological edge of the concept of superconducting radio frequency injectors is to combine the strengths of both these sides. As many future accelerator concepts, such as energy recovery linacs, high power free electron lasers and certain collider designs, demand particle sources with high bunch charges and high repetition rates combined, applying the superconductivity of the accelerator modules to the injector itself is the next logical step. However, emittance compensation — the cornerstone for high beam quality — in case of a superconducting injector is much more challenging than in the normal conducting one. The use of simple electromagnets generating a solenoid field around the gun’s resonator interferes with its superconducting state. Hence, it requires novel and sophisticated techniques to maintain the high energy gain inside the gun cavity, while at the same time alleviating the detrimental fast transverse emittance growth of the bunch. In the case of the ELBE accelerator at the Helmholtz-Zentrum Dresden-Rossendorf, a superconducting electron accelerator provides beam for several independent beamlines in continuous wave mode. The applications include IR to THz free electron lasers, neutron and positron generation, to Thompson backscattering with an inhouse TW laser, and hence, call for a flexible CW injector. Therefore, the development of a 3.5 cell superconducting electron gun was initiated in 1997. The focus of this thesis lies on three approaches of transverse emittance compensation for this photoinjector: RF focusing, the installation of a superconducting solenoid close to the cavity’s exit, and the introduction of a transverse electrical mode of the RF field in the resonator. All three methods are described in theory, examined by numerical simulation, and experimentally reviewed in the particular case of the ELBE SRF Gun II at HZDR and a copy of its niobium resonator at Thomas Jefferson National Laboratory, Newport News, VA, USA.

The ATLAS detector at CERN's Large Hadron Collider has been instrumental in scientific discoveries,including the Higgs particle. As part of the High Luminosity (HL) upgrade, the current Inner Detector (ID) isbeing replaced by the new IInner Tracker (ITk), and Uppsala University is collaborating with industrypartner NOTE to produce around 700 modules for the ITk. The production process involves gluing hybridsto sensors using a glue robot, which currently lacks a complete metrology system needed to verify thegeometry of produced items. This project aims to integrate a Micro Epsilon ILD1900 laser sensor with theglue robot to enable accurate measurements in the z-axis. In order to reach this goal, a few differenttasks had to be completed. These included creating a measurement API to enable the utilisation of thelaser sensor, recommending modifications to the glue robot syringe and camera holder in order to holdthe laser sensor, performing validation tests of the laser sensor's measuring capability, developing a lasersensor mount for a mock-up glue robot used during the validation process and developing a holder for aUSB/RS422 converter necessary for communication with the laser sensor. As a result of the project, themeasurement API was successfully created and utilised, appropriate modifications to the syringe holderwere made, validation tests were conducted though deemed insufficient due to limitations of the setup,and, finally, the laser sensor mount for the mock-up glue robot and the USB/RS422 holder weresuccessfully designed and produced.

Free-electron lasers (FELs) are among the world's most intense artificial artificial sources of coherent light and are tunable to various wavelengths, including the X-ray spectrum. X-ray FELs (XFELs) are extremely useful for diffraction experiments to study molecules, materials, and quantum systems. A FEL consists of an electron accelerator and a structure of magnets called an undulator. The undulator has a periodic magnetic field, and when an electron beam passes through the undulator, the Lorentz force forces the electrons to oscillate and emit what is known asspontaneous undulator radiation. Initially, the undulator radiation is spontaneously emitted and incoherent. However, aAs the electrons interact with this initial spontaneous undulator radiation, they change their relative positions and form micro-bunches of electrons. These microbunches are shorter than the undulator radiation wavelength. Hence, the waves emitted by the electrons from the same microbunch arethey become in phase, meaning the radiation is now coherent with the radiation field, and the state of coherence develops. This process is known as self-amplified spontaneous emission (SASE). Due to the coherence, tThe radiation intensity grows exponentially along the undulator, forming several peaks in the radiation pulse known as SASE spikes. One technique for obtaining ultra-short laser pulses is to isolate single SASE spikes by controlling where, along the electron beam, the SASE spikes can grow. This growth limitation is archieved by modulating the electron energies, thus only allowing electrons at specific positions along the electron beam to radiate. In addition, to keep positive interference between undulator radiation from electrons with different energies, the energy modulation must be compensated with a gradient of the magnetic field amplitude of the undulator, so-called tapering. There are plans to implement this technique at one of the beamlines at the European X-ray FEL (EuXFEL) to generate attosecond X-ray pulses and study quantum systems. One goal of the design process is to choose design parameters for the electron beam's modulation amplitude and the undulator's tapering coefficient. These design parameters shall be chosen so that the XFEL will have as short pulse duration as possible while at the same time not getting too low peak power. This thesis aims to study the effect of electron energy modulation and undulator tapering on the SASE and how the modulation amplitude and the tapering coefficient affect the XFEL's peak power and pulse duration. A model was developed to simulate SASE with a modulated electron beam in a tapered undulator. With this model, a parameter scan gave the average peak power and pulse duration as functions of the modulation amplitude and the tapering coefficient. The parameter scan showed that the peak power and the pulse duration decrease as the modulation amplitude and the tapering coefficient increase. Therefore, a trade-off exists between high peak power and short pulse duration. It was possible to exclude sets of the parameters that gave too low peak power or long pulse duration. This study also found an optimum range for the tapering coefficient where the peak power had a local maximum without a significant increase in pulse duration. The physics behind this optimal tapering coefficient is also discussed in connection to the electrons' energy modulation.

During the Apollo 10 and 17 missions NASA astronauts reported that they saw streamers emanating from the surface of the moon. They concluded that the streamers were produced by light scattering from dust particles. The particles are believed to be transported by an ambient electric field. This theorized electric field has never been measured directly, although the electric potential on the surface and above it has. The exact behavior and origin of the electric field is unknown, but has been approximated to be between 1 and 12 V/m. To measure this electrical field a new type of instrument, called Multi Plate Field Mills (MPFM) has been developed. This type of instrument is capable of measuring both the amplitude and directionality of the electrical field. Three of these instruments will be mounted on a 1U CubeSat to be lunched with the PTS mission to the moon scheduled to Q4 2019. In this work the MPFM were characterized. The precision of the instrument for electrical fields applied along the z, y and x axis was found to be 0.6, 1.3, 1.4 (V/m)/(Hz)^(1/2) respectively for measurements in air and 0.14, 0.6, 0.6 (V/m)/(Hz)^(1/2) for measurements in vacuum. This sensitivity outperforms the current state of the art Field Mills and, in addition to that, it provides an assessment of the directionality of the electrical field. / Umeå Lunar Venture