Neutron-carbon interactions have been studied with a focus on charged-particle production of relevance to radiation protection and medical applications, such as cancer therapy. The measurements have been performed using the particle-detection setup, MEDLEY, and the 96 MeV neutron beam at the The Svedberg Laboratory in Uppsala. Double-differential cross sections of inclusive charged-particle production are compared with recent calculations from models based on the GNASH code including direct, preequilibrium and compound processes. For protons, the shapes of the cross-section spectra are reasonably well described by the calculations. For the other particles- d, t, 3He and α- there are important discrepancies, in particular for 3He-ions and α-particles, concerning both shape and magnitude of the spectra. Using the new cross sections, partial as well as total KERMA coefficients have been determined. The coefficients have also been compared to previous experimental results and model calculations. The p, d and t KERMA coefficients are in good agreement with those from a previous measurement. For the helium isotopes, there are no previous measurements at this energy. The KERMA coefficients are considerably higher (by up to 30%) than those predicted by the calculations. The KERMA results indicate that protons and α -particles are the main contributors to the dose. A 6x6x6 cm3 carbon phantom, exposed to a broad and a pencil-like beam, is used for the computation of the absorbed doses deposited by these two particles in spheres of 1 μm in diameter, located at various positions in the phantom. The maximum doses are deposited at ~3 cm from the surface of neutron impact for protons and within 1 cm for α-particles. For the pencil beam, deposited doses are spread over regions of ~1.5 cm and ~300 μm transverse to the beam for protons and α-particles, respectively. The results are consistent with previous integral measurements at lower energies.

Ce travail contribue au programme de recherche et de développement d'un capteur CMOS à pixel qui pourrait satisfaire pleinement les spécifications du nouvel ITS (Inner Tracking System : trajectomètre interne) de l'expérience ALICE. Afin de briser les limites de la CPS de pointe, une technologie CMOS 0.18 µm à quatre puits a été explorée. Les capteurs fabriqués dans cette nouvelle technologie ont montré une meilleure tolérance aux radiations que les capteurs réalisés dans une technologie CMOS 0.35 µm plus ancienne. En outre, cette nouvelle technologie offre la possibilité d’implémenter des transistors de type P dans chaque pixel sans dégrader la capacité de collection de la diode. Il devient donc possible d’intégrer un discriminateur dans chaque pixel et obtenir un pixel à sortie binaire. En conséquence, la consommation sera largement réduite. De plus, le temps de traitement de la ligne peut être potentiellement réduit. Un premier prototype de petite taille, intitulé AROM-0, a été conçu et fabriqué afin d’étudier la faisabilité de la discrimination de signal dans un petit pixel. Dans ce prototype, chaque pixel de surface 22 × 33 µm2 contient une diode de détection, un préamplificateur et un discriminateur à tension d’offset compensée. La performance de bruit des différentes versions de pixels dans le capteur AROM-0 a été évaluée. Ensuite sera détaillé le développement des capteurs AROM-1. Ce sont les capteurs intermédiaires vers le capteur final proposé par notre groupe. Ils ont deux objectifs principaux, l’un est de valider les optimisations de conception du pixel et l’autre est de mettre en place une architecture du capteur évolutive intégrant l’intelligence nécessaire dans le circuit. Cette thèse présente en détail la conception et les résultats de mesure de ces capteurs AROM. / This work is part of the R&D program aimed for a CMOS pixel sensor (CPS) complying with the requirements of the upgrade of the inner tracking system (ITS) of the ALICE experiment. In order break the limitations of the state-of-the-art CPS, a 0.18 µm quadruple-well CMOS process was explored. Besides an enhanced radiation tolerance, with respect to the former sensors fabricated in a 0.35 µm process, the sensor based on this new process allows for full CMOS capability inside the pixel without degradation of the detection efficiency. Therefore, the signal discrimination, which was formerly performed at the column level, can be integrated inside the pixel. As a result, the readout speed and power consumption can be greatly improved as compared to the CPS with column-level discrimination. This work addresses the feasibility study of achieving the signal discrimination withina small pixel (i.e. 22 × 33 µm2), via the prototype named AROM-0. The pixel of AROM-0 contains a sensing diode, a pre-amplifier and an offset compensated discriminator. The noise performance of the various pixel versions implemented in AROM-0 was evaluated. The study was further pursued with the AROM-1 prototypes, incorporating the optimized pixel designs and the necessary on-chip intelligence to approach the final sensor we have proposed for the ALICE-ITS upgrade. This thesis presents in detail the design and the measurement results of these AROM sensors.

Hadron Therapy (HT) exploits properties of ion radiation to gain therapeutic advantages over existing photon-based forms of external radiation therapy. However, its relative superiority and cost-effectiveness have not been proven for all clinical situations. Establishing a robust evidence base for the development of best treatment practices is one of the major challenges for the field. This thesis investigates two research infrastructures for building this essential evidence. First, the thesis develops main components of a metadata-driven software architecture for the collection of clinical information and its analysis. This architecture acknowledges the diversity in the domain and supports data interoperability by sharing information models. Their compliance to common metamodels guarantees that primary data and analysis results can be interpreted outside of the immediate production context. This is a fundamental necessity for all aspects of the evidence creation process. A metamodel of data capture forms is developed with unique properties to support data collection and documentation in this architecture. The architecture's potential to support complex analysis processes is demonstrated with the help of a novel metamodel for Markov model based simulations, as used for the synthesis of evidence in health-economic assessments. The application of both metamodels is illustrated on the example of HT. Since the biological effect of particle radiation is a major source of uncertainty in HT, in its second part, this thesis undertakes first investigations towards a new research facility for bio-medical experiments with ion beams. It examines the feasibility of upgrading LEIR, an existing accelerator at the European Organisation for Nuclear Research (CERN), with a new slow extraction and investigates transport of the extracted beam to future experiments. Possible configurations for the slow-resonant extraction process are identified, and designs for horizontal and vertical beam transport lines developed. The results of these studies indicate future research directions towards a new ion beam facility for biomedical research.

Weiche inelastische QCD Prozesse dominieren am LHC. Über 20 solcher Kollisionen werden innerhalb einer Strahlkreuzung bei ATLAS stattfinden, sobald der LHC die nominelle Luminosität von L = 1034 cm−2 s−1 und die Schwerpunktsenergie von p s = 14 TeV erreicht. Diese inelastischen Wechselwirkungen sind durch einen geringen Impulsübertrag gekennzeichnet, welche theoretisch lediglich durch phänomenologische Modelle angenähernd beschrieben werden können. Zu Beginn des Strahlbetriebs des LHC’s 2009 war die Luminosität relativ niedrig mit L = 1027 bis 1031 cm−2 s−1, was ein sehr gutes Szenario bot, um einzelne Proton-Proton Kollisionen zu selektieren und deren allgemeine Eigenschaften experimentell zu untersuchen. Zunächst wurde ein Minimum-Bias Trigger entwickelt, um Daten mit ATLAS aufzunehmen. Dieser Trigger, mbSpTrk, verarbeitet Signale der Silizium-Spurdetektoren und verwirft effizient Ereignisse ohne eine Proton-Wechselwirkung, wobei zugleich eine mögliche Verschiebung zu bestimmten Ereignistypen hin minimier wird. Um einen flexiblen Einsatz des Triggers zu gewährleisten, wurde er mit einer Sequenz ausgestattet, welche effizient Machinenuntergrund unterdrückt. Im zweiten Teil der Arbeit wurden geladenen Teilchenmultiplizitäten im zentralen Bereich in zwei kinematisch definierten Phasenräumen gemessen. Mindestens ein geladenes Teilchen mit einer Pseudorapidität kleiner als 0.8 und einem Transversalimpuls von pT > 0.5 bzw. 1 GeV musste vorhanden sein. Vier typische Minimum-Bias Verteilungen wurden bei zwei Schwerpunktsenergien von p s = 0.9 und 7 TeV gemessen. Die Ergebnisse sind derart präsentiert, dass sie nur minimal von Monte Carlo Modellen abhängen. Die vorgestellten Messungen stellen zudem den Beitrag der ATLAS Kollaboration dar für die erste, LHC-weit durchgeführte Analyse, der auch die CMS und ALICE Kollaborationen zustimmten. Ein Vergleich konnte mit den Pseudorapiditätsverteilungen angestellt werden. / Soft inelastic QCD processes are the dominant proton-proton interaction type at the LHC. More than 20 of such collisions pile up within a single bunch-crossing at ATLAS, when the LHC is operated at design luminosity of L = 1034 cm−2 s−1 colliding proton bunches with an energy of p s = 14 TeV. Inelastic interactions are characterised by a small transverse momemtum transfer and can only be approximated by phenomenological models that need experimental data as input. The initial phase of LHC beam operation in 2009, with luminosites ranging from L = 1027 to 1031 cm−2 s−1, offered an ideal period to select single proton-proton interactions and study general aspects of their properties. As first part of this thesis, a Minimum Bias trigger was developed and used for data-taking in ATLAS. This trigger, mbSpTrk, processes signals of the silicon tracking detectors of ATLAS and was designed to fulfill efficiently reject empty events, while possible biases in the selection of proton-proton collisions is reduced to a minimum. The trigger is flexible enough to cope also with changing background conditions allowing to retain low-pT events while machine background is highly suppressed. As second part, measurements of inelastic charged particles were performed in two phase-space regions. Centrally produced charged particles were considered with a pseudorapidity smaller than 0.8 and a transverse momentum of pT > 0.5 or 1 GeV. Four characteristic distributions were measured at two centre-of-mass energies of p s = 0.9 and 7 TeV. The results are presented with minimal model dependency to compare them to predictions of different Monte Carlo models for soft particle production. This analysis represents also the ATLAS contribution for the first common LHC analysis to which the ATLAS, CMS and ALICE collaborations agreed. The pseudorapidity distributions for both energies and phase-space regions are compared to the respective results of ALICE and CMS.

L’étude des mécanismes de production des quarkonia (J/ψ or Υ) dans les collisions proton-proton (pp) est intéressante car elle nécessite de prendre en compte les aspects perturbatifs et non perturbatifs de la ChromoDynamique Quantique (QCD). La production de quarkonia en fonction de la multiplicité des particules chargées a été mesurée pour la première fois dans les collisions pp avec le détecteur ALICE au Grand collisionneur de hadrons (LHC). Ces mesures présentent une corrélation non triviale qui peut conduire à une meilleure compréhension du mécanisme d’interaction partonique multiple dans l’état initial de la collision ainsi que des effets collectifs possibles dans les petits systèmes. L’étude du dernier échantillon de données enregistré au LHC en collisions pp aux énergies les plus élevées jamais atteintes en laboratoire (√s=13 TeV) permettra d’étudier des événements à forte multiplicité. Avec ALICE, les quarkonia sont mesurés jusqu’à des impulsions transverses nulles. Les charmonia (J/ψ, cc̄ ) sont détectés par leur désintégration en diélectrons à mi-rapidité (|y|< 0.9) et en dimuons en rapidité vers l’avant (2.5 < y < 4). Les bottomonia (Υ, bb̄) sont détectées par leur décroissance en dimuons en rapidité vers l’avant. La multiplicité des particules chargées est mesurée à l’aide de segments de traces avec le détecteur de silicium à pixels pour |η|< 1. Dans cette thèse, nous présenterons les premières mesures réalisées avec ALICE des productions relatives d’Υ(1S) et Υ(2S) en fonction de la multiplicité des collisions pp à √s =13 TeV. Nous discuterons du rapport relatif des Υ(2S) par rapport aux Υ(1S) en fonction de la multiplicité des particules chargées. La comparaison entre les J/ψ et les Υ(1S) mesurés en rapidité avant en fonction de la multiplicité sera également examinée. Ces études permettront d’examiner la dépendance possible de la corrélation mesurée avec les différentes masses des quarkonia considérés et les différents types de contenus en quark. La dépendance du domaine en rapidité et de l’énergie de la collision sera également considérée. / The study of quarkonium (J/ψ or Υ) in proton-proton (pp) collisions is interesting as both perturbative and non perturbative aspects of Quantum ChromoDynamics (QCD) are involved in the production mechanism. The quarkonium production as a function of charged-particle multiplicity has been measured in a pp collisions with ALICE detector at the Large Hadron Collider (LHC). They exhibit a non-trivial correlation that can lead to a better understanding of the multi-parton interaction mechanism in the initial state of the collision as well as possible collective effects in small systems. Thestudy of latest data sample recorded at the LHC in pp collisions at the highest collision energies everreached in the laboratory (√s = 13 TeV) will allow to investigate high multiplicity events. In ALICE,quarkonia are measured down to zero transverse momentum. Charmonia (J/ψ, cc̄) are detected viatheir decay into di-electrons at mid-rapidity (|y|< 0.9) and dimuons at forward rapidity (2.5 < y < 4).Bottomonia (Υ, bb̄) are detected via their decay into dimuons at forward rapidity. Charged-particlemultiplicity is measured using track segments in the silicon pixel detector in |η|< 1. In this thesis, we will present the first ALICE measurements of relative Υ(1S) and Υ(2S) productions as a function of multiplicity in pp collisions at √s =13 TeV. We will discuss the ratio of the relative Υ(2S) overΥ(1S) as a function of charged-particle multiplicity. The comparison between the relative J/ψ andΥ(1S) yields measured at forward rapidity as a function of multiplicity will also be discussed. This will provide insight of possible dependence of the measured correlation with different mass and quark contents as well as the evolution with rapidity range and the collision energy.