Search

RESUMEN Se presenta la medida de la sección eficaz de producción de un par de bosones W+W- en colisiones protón-protón a una energía de centro de masas de 13 TeV. Los datos analizados en este estudio han sido recogidos por el detector CMS del LHC, y se corresponden con una luminosidad integrada de 35.9 fb-¹. Los eventos candidatos se seleccionan requiriendo dos leptones con carga opuesta. Se mide una sección eficaz de producción total de 117.6 ± 6.8 pb, que acuerda bien con la predicción teórica. También se hacen medidas de las secciones eficaces fiduciales y diferenciales, que acuerdan bien con las predicciones teóricas. Finalmente, se obtienen límites en los operadores de dimensión-6 en el contexto de la teoría de campo efectivo. Este análisis proporciona algunos de los límites más fuertes en dichos operadores comparando con resultados previos. Se realiza una búsqueda de materia oscura en colisiones protón-protón a una energía de centro de masa de 13 TeV usando eventos con un par de bosones W+W- y una gran cantidad faltante de momento transverso. Los datos usados en este estudio han sido recogidos por el detector CMS del LHC, y se corresponden con una luminosidad integrada de 137 fb-¹. Los eventos candidatos se seleccionan requiriendo dos leptones con carga opuesta. No se observa ningún exceso significativo de los datos sobre las predicciones del Modelo Estándar, por lo que se obtienen límites en la producción de materia oscura en el contexto del modelo simplificado de Higgs oscuro, con una masa para el bosón de Higgs oscuro por encima de la masa umbral del par W+W-. Los resultados presentados se corresponden con la primera medida realizada por el experimento CMS usando esta nueva interpretación. Se aplican técnicas de aprendizaje automático profundo para estimar el momento transverso de muones altamente energéticos en el detector CMS. El objetivo principal de estos estudios es mejorar los resultados del procedimiento utilizado actualmente, y de ser así, considerar incluir este tipo de metodologías en la futura toma de datos del experimento. Los resultados preliminares, basados en simulación, muestran una mejora de aproximadamente un 25% en la resolución de la asignación de momento transverso para muones con with 1500 < pT < 2500 GeV y |η| < 0.9. ABSTRACT A measurement of the W+W- boson pair production cross section in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The data used in this study are collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 fb-¹. The W+W- candidate events are selected by requiring two oppositely charged leptons. The total W+W- production cross section measurement has been 117.6 ± 6.8 pb, which agrees well with the theoretical prediction. Fiducial cross sections and differential cross sections are also reported, which also agree well with the theoretical prediction. Finally, constraints on the dimension-6 operators in the context of an effective field theory are derived. This analysis provides some of the strongest constraints compared with previous results. A search for dark matter in proton-proton collisions at a center-of-mass energy of 13 TeV is performed using events with a W+W- boson pair and large missing transverse momentum. The data used in this study are collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb-¹. The W+W- candidate events are selected by requiring two oppositely charged leptons. No significant excess over the expected Standard Model prediction is observed. Limits are set on dark matter production in the context of the dark Higgs simplified model, with a dark Higgs mass above the W+W- pair mass threshold. The results presented correspond to the first measurement carried out in the CMS experiment using this novel interpretation. Deep learning techniques are applied to estimate the transverse momentum of highly energetic muons in the CMS detector. The main goal of these studies is to improve the results of the current procedure, and if so, consider including these types of methodologies in the future data taking of the experiment. The preliminary results obtained, based on simulation, show an improvement of about 25% in the resolution of the transverse momentum for muons with 1500 < pT < 2500 GeV and |η| < 0.9.

RESUMEN: El objetivo de este trabajo es medir con la máxima precisión posible la sección eficaz de producción de un par de bosones W en colisiones protón-protón a una energía de centro de masas de √s = 13 TeV. Para ello, se han utilizado datos recogidos por el experimento Compact Muon Soleniod (CMS) y una luminosidad total de L = 36.3 fb−1. Esta medida es una prueba directa de las predicciones del modelo estándar para la interacción electrodébil, además de ser útil para el estudio del bosón de Higgs decayendo a dos bosones W. Para ello, se han estudiado eventos en los que cada bosón W decae a un leptón y a un neutrino, por lo que se espera encontrar dos leptones y energía transversa faltante en el estado final. En concreto, solo se han considerado los eventos con dos leptones de distinto sabor, electrones o muones, y de carga contraria. El análisis se ha realizado seleccionando eventos con 0, 1 y 2 jets de manera independiente y se ha basado en encontrar una región lo más pura posible en procesos de la señal que se quiere estudiar, utilizando para ello el poder discriminatorio de ciertas variables cinemáticas. Una vez definida esta región, se ha procedido a realizar una primera medida de la sección eficaz de producción. Con el objetivo de mejorar la precisión de la medida, se ha procedido a medir dicha sección eficaz a partir del ajuste a ciertas distribuciones de las variables estudiadas. Por último, en el caso particular de los eventos con 2 jets, se ha necesitado buscar un método de mejora de esta medida, para lo cual se han utilizado técnicas de aprendizaje automático, en concreto un conjunto de árboles de decisión (BDT) capaces de mejorar la selección de eventos. Específicamente, el algoritmo utilizado ha sido entrenado para diferenciar entre fondo y señal. Los resultados obtenidos para los procesos con 0 y 1 jet son coherentes con las predicciones del modelo estándar para todas las estrategias utilizadas. En el caso de los eventos donde se requerían 2 jet, los resultados más precisos han sido los obtenidos al aplicar el BDT, siendo compatibles con el modelo estándar. ABSTRACT: The aim of this work is to measure with the highest possible precision the production cross section of two opposite charged W bosons in proton-proton collisions at a center of mass energy of √ s = 13 TeV, by using data collected by the Compact Muon Solenoid (CMS) experiment corresponding to a total luminosity of L = 36.3 fb−1. This measurement is a direct test of the predictions of the Standard Model (SM) in electroweak interaction, as well as being an important process in the study of Higgs boson decaying to two W bosons. In this work, it is considered that each of the W bosons decays to a lepton and a neutrino, so it is expected to find two leptons with different charge (electrons or muons) and missing transverse energy in the final signature. In particular, only events with different-flavored leptons have been considered. The analysis has been performed independently for processes with 0, 1 and 2 jets and it has been based on searching for a region which magnifies the signal over the backgrounds by using the discriminating power of certain kinematic variables. Once that region was defined, a first measurement of the production cross section was obtained. Then, a binned likelihood fit has been performed to certain variables, providing another measurement of the cross section. Finally, in the events with 2 jets, it was necessary to search for a method that improved the result. Techniques of machine learning able to improve the selection of events have been used for this purpose, obtaining another different cross section measurement. Specifically, the algorithm used has been a set of decision trees (BDT) trained to differentiate signal from background. In the processes in which 0 and 1 jets were required, the measured cross section values for each of the different strategies used are all in agreement with the SM predictions. In the 2-jet requirement, the most precise value of the cross section came from using a BDT, providing a measurement compatible with the SM. Grado en Física

Das Standardmodell (SM) der Teilchenphysik, eine Theorie der derzeitig bekannten Elementarteilchen und deren Wechselwirkungen, liefert pr��zise Vorhersagen in ��bereinstimmung mit experimentellen Ergebnissen. Es z��hlt, trotz bekannter Unvollst��ndigkeit, zu einer der am strengsten getesteten Theorien. Ist die Masse neuer Teilchen f��r derzeitige Teilchenbeschleuniger wie dem Large Hadron Collider (LHC) am CERN jedoch nicht erreichbar, so wird der Nachweis ihrer Existenz in Abweichung kinematischer Spektren der SM Teilchen bei geringeren Energien sichtbar. Das Top-Quark spielt in vielen Theorien jenseits des SM eine wichtige Rolle. Seine Wechselwirkungen, im Speziellen die elektromagnetische Top-Quark-Photon Kopplung, sind sensitiv auf Einfl��sse neuer Physik. Die Messung der inklusiven und differentiellen Produktionswechselwirkungsquerschnitte eines Top-Quark Paares in Verbindung mit einem Photon (ttgamma) erm��glicht den Zugang zu dieser Kopplung. F��r die Messung der inklusiven und differentiellen ttgamma Produktionswechselwirkungsquerschnitte wird ein vom CMS Experiment in der LHC Run 2 (2016-2018) Datenaufnahme aufgezeichneter Datensatz von 137 fb-1 integrierter Luminosit��t an Proton-Proton Kollisionen bei einer Schwerpunktsenergie von sqrt(s) = 13 TeV verwendet. Zur Analyse herangezogene Ereignisse m��ssen ein geladenes Lepton (Elektron oder Myon), ein isoliertes Photon, mindestens drei Jets aus der Hadronisierung von Quarks, von denen mindestens einer von einem Bottom-Quark stammt, aufweisen. Das Photon kann von einem Quark im Anfangszustand, dem Top-Quark oder den Zerfallsprodukten des Top-Quarks emittiert werden. Der inklusive Produktionswechselwirkungsquerschnitt des ttgamma Prozesses wird f��r einen transversalen Photon-Impuls gr����er als 20 GeV und einem Absolutwert der Pseudorapidit��t |eta| < 1.4442 gemessen. Der gemessene ttgamma Produktionswechselwirkungsquerschnitt von 798 +- 7 (stat) +- 48 (syst) fb ist in guter ��bereinstimmung mit der SM Vorhersage von 773 +- 135 fb in Simulationen n��chst-f��hrender Ordnung in Quantenchromodynamik. Differentielle Produktionswechselwirkungsquerschnittsmessungen werden in diversen kinematischen Observablen durchgef��hrt und auf die Teilchenebene entfaltet, was einen Vergleich mit theoretischen Vorhersagen erm��glicht. Die Messungen werden im Kontext der effektiven Feldtheorie des SM interpretiert und f��r die derzeit st��rkste Einschr��nkung anormaler elektromagnetischer Dipolmomente des Top-Quarks verwendet., The standard model (SM) of particle physics, a theory of the currently known elementary particles and their fundamental interactions, provides predictions in agreement with experimental results up to the highest achievable precision. It is one of the most stringently tested theories, still known to be incomplete. If we suppose that new particles are too heavy for discovery at the Large Hadron Collider (LHC) at CERN, indirect effects can still be discernible in deviations in kinematic spectra at much lower energies. Because the top quark plays a crucial role in many beyond the SM theories, its interactions are sensitive probes of new physics phenomena. In particular, the measurement of the inclusive and differential cross sections of a top quark pair in association with a photon (ttgamma) will access the electromagnetic top quark coupling. A data set of 137 fb-1 integrated luminosity of proton-proton collisions at a center-of-mass energy of sqrt(s) = 13 TeV, recorded by the CMS experiment during the LHC Run 2 (2016-2018) data taking, is used for the measurement of the inclusive and differential ttgamma cross sections. Events are selected by requiring one charged lepton (electron or muon), one isolated photon, and at least three jets from the hadronization of quarks, where at least one has to originate from a bottom quark. The photon may be emitted from an initial-state quark, the top quark, or any decay product of the top quark. The inclusive cross section of the ttgamma process is measured for a photon transverse momentum greater than 20 GeV and absolute value of the pseudorapidity |eta| < 1.4442. The measured ttgamma cross section in the fiducial phase space of 798 +- 7 (stat) +- 48 (syst) fb is in good agreement with the SM prediction of 773 +- 135 fb from simulations at next-to-leading order in quantum chromodynamics. Differential cross section measurements are performed in several kinematic observables and unfolded to the particle level, allowing for comparisons to theoretical predictions. The measurements are interpreted in terms of the SM effective field theory and are used to set constraints on anomalous electromagnetic dipole interactions of the top quark that are the most stringent to date.

In the framework of a systematic study of proton induced nuclear reactions on lanthanides we have measured the excitation functions on natural cerium for the production of (142,139,138m,137)pr, Ce-141.139,Ce-137m,Ce-137g,Ce-135 and La-133 up to 65 MeV proton energy using the activation method with stacked foil irradiation technique and high-resolution gamma-ray spectrometry. The cross-sections of the investigated reactions were compared with the data retrieved from the TENDL-2014 and TENDL-2015 libraries, based on the latest version of the TALYS code system. No earlier experimental data were found in the literature. The measured cross-section data are important for further improvement of nuclear reaction models and for practical applications in nuclear medicine, other labeling and activation studies. (C) 2017 Elsevier B.V. All rights reserved.

In the last decade a continuous increase in the numberof cancer patients treated with Particle Therapy (CPT) has been registered. CPTis still a discipline where the contribution coming from research in physicsplays an important role. For example, different studies have shown that inproton therapy nuclear inelastic interactions of the incident beam with thepatient tissues may lead to the fragmentation of the target nuclei producing anon negligible amount of target fragments, which may alter the estimated localdose deposition, especially in the entrance region. On the other hand, in heavyion treatments, the main effect of nuclear inelastic interactions results inthe break up of the incident ion instead of the target nuclei. The producedfragments have a longer range than the projectile, leading to an undesirabledose deposition beyond the Bragg peak. At present there is still a lack ofcomplete and reliable experimental measurements of nuclear reaction crosssections for fragments produced in the interaction with tissues nuclei (H, C,Ca, O, N) of 60-250 MeV protons and 100-400 MeV/u carbon ions, which are thetypical energies adopted in CPT treatments. These data will be important todevelop a new generation of high quality treatment planning systems for CPT. The FOOT (FragmentatiOn Of Target) experiment aims tofill the gap, performing a set of measurements of nuclear fragmentation crosssections relevant for CPT. As far thestudy of target fragmentation is concerned, the FOOT experiment will adopt aninverse kinematic approach to overcome the difficulties related to the shortfragments range (∼μm). In order to bypass the difficulties to manage apure hydrogen target, it has been chosen a strategy of a double targetseparately made of C and C2H4 and the final cross sectionon Hydrogen will be obtained by subtraction. Further interest in this type ofmeasurements comes from the issue of radioprotection in space missions, wherethe energy to be considered is higher and close to 1 GeV/u. FOOT consists oftwo different setups depending on the detection of heavy and light fragments:the heavy fragments are detected by a high precision tracking system inmagnetic field, a time of flight measurement system and a calorimeter, whilethe lighter ones by a separated emulsion chamber. The optimization and theperformance analysis of the setup have studied by means of the FLUKA(1)(2)(3)Monte Carlo code and different detectors have been tested.In this work, an overview of the FOOT experiment and areport on the study of the detector performances will be presented.

Sn-117m is one of the radioisotopes can be beneficially produced through alpha particle irradiation. The targets were prepared by deposition of Cd-116 metal onto high purity 12 mu m thick Cu backing. The average deposited thickness was 21.9 mu m. The beam energy was thoroughly measured by Time of Flight (TOF) methods and proved to be 51.2 MeV. For the experiment the well-established stacked foil technique was used. In addition to the Cd targets, Ti foils were also inserted into the stacks for energy and intensity monitoring. The Cu backings were also used for monitoring and as recoil catcher of the reaction products from the cadmium layer. The activities of the irradiated foils were measured with HPGe detector for gamma-ray spectrometry and cross section values were determined. As a result excitation functions for the formation of Sn-117m, In-117m,In-g, In-116m In-115m and Cd-115m,Cd-g from enriched Cd-116 were deduced and compared with the available literature data and with the results of the nuclear reaction model code calculations EMPIRE 3.2 and TALYS 1.8. Yield curves were also deduced for the measured nuclear reactions and compared with the literature.

et al., We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb−1 per experiment. The t-channel cross section is measured to be σt=2.25+0.29−0.31 pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in σs+t=3.30+0.52−0.40 pb, without assuming the standard model value for the ratio σs/σt. The resulting value of the magnitude of the top-to-bottom quark coupling is |Vtb|=1.02+0.06−0.05, corresponding to |Vtb|>0.92 at the 95% C.L., We acknowledge support from the Department of Energy and the National Science Foundation (U.S.A.), the Australian Research Council (Australia), the National Council for the Development of Science and Technology and the Carlos Chagas Filho Foundation for the Support of Research in the State of Rio de Janeiro (Brazil), the Natural Sciences and Engineering Research Council (Canada), the China Academy of Sciences, the National Natural Science Foundation of China, and the National Science Council of the Republic of China (China), the Administrative Department of Science, Technology and Innovation (Colombia), the Ministry of Education, Youth and Sports (Czech Republic), the Academy of Finland, the Alternative Energies and Atomic Energy Commission and the National Center for Scientific Research/National Institute of Nuclear and Particle Physics (France), the Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Research) and the Deutsche Forschungsgemeinschaft (German Research Foundation) (Germany), the Department of Atomic Energy and Department of Science and Technology (India), the Science Foundation Ireland (Ireland), the National Institute for Nuclear Physics (Italy), the Ministry of Education, Culture, Sports, Science and Technology (Japan), the Korean World Class University Program and the National Research Foundation of Korea (Korea), the National Council of Science and Technology (Mexico), the Foundation for Fundamental Research on Matter (Netherlands), the Ministry of Education and Science of the Russian Federation, the National Research Center “Kurchatov Institute” of the Russian Federation, and the Russian Foundation for Basic Research (Russia), the Slovak R&D Agency (Slovakia), the Ministry of Science and Innovation, and the Consolider-Ingenio 2010 Program (Spain), the Swedish Research Council (Sweden), the Swiss National Science Foundation (Switzerland), the Ministry of Education and Science of Ukraine (Ukraine), the Science and Technology Facilities Council and the The Royal Society (United Kingdom), the A. P. Sloan Foundation (U.S.A.), and the European Union community Marie Curie Fellowship Contract No. 302103.

The WZ associated diboson production is studied by measuring both inclusive cross section and, for the first time, the ratio between the W¯Z and the W⁺Z cross sections. The measurements are performed using data samples of proton-proton collisions collected during the years 2011 and 2012, at 7 and 8 TeV of centre-of-mass energies, respectively, by the CMS experiment at the LHC, updating the 7 TeV cross section measurement available in CMS, and presenting the new cross section measurement in CMS at 8 TeV. The data sample used for the 7 TeV measurements correspond to an integrated luminosity of 4.9 fb¯¹, whence the data for the 8 TeV correspond to Lint = 19.6 fb¯¹. RESUMEN: El estudio de la producción asociada de dibosones WZ mediante la medida de su sección eficaz inclusiva y, por primera vez, el cociente entre las secciones eficaces de los procesos W¯Z y W⁺Z, es el objeto de este trabajo de tesis. Las medidas se han realizado utilizando muestras de datos de colisiones protón-protón almacenadas por el experimento CMS del LHC durante los años 2011 y 2012, a energías del centro de masas 7 TeV y 8 TeV respectivamente. Las medidas presentadas en esta tesis actualizan la medida de sección eficaz de producción del proceso WZ a 7 TeV que disponía CMS hasta la fecha y añade la nueva medida de sección eficaz del WZ a 8 TeV, junto con las medidas de cociente W¯Z y W⁺Z tanto a 7 TeV como a 8 TeV. La muestra de datos utilizada para las medidas a 7 TeV corresponden a una luminosidad integrada de 4.9 fb¯¹, mientras que los datos para 8 TeV corresponden a Lint = 19.6 fb¯¹.

The high-specific activity 99Mo accelerator-based production, via the (α,n) reaction on 96Zr-enriched target, has been investigated in the present work. The excitation function measurement has been performed in the energy range 8–34 MeV at the ARRONAX facility, using the well-known stacked foils technique on natural zirconium as target. A general good agreement in the cross section trend has been observed, once compared to former measurements. A different (i.e. higher) peak value and a shift of about 2 MeV towards larger energies have however been found. Assuming a fully enriched 96Zr target irradiated by an α-beam at suitable energy (E = 25 MeV), the 99Mo production yield has thus been estimated. At last the alternative production routes, based on the 96Zr(α,n)99Mo and 100Mo(p,x)99Mo/99mTc reactions, are compared.

119 σ., Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Φυσική και Τεχνολογικές Εφαρμογές”, Η ενεργός διατομή της αντίδρασης 241Am(n,2n)240Am, μετρήθηκε με τη μέθοδο της ενεργοποίησης σε σχέση με αυτές των αντιδράσεων 27Al(n,a)24Na, 197Au(n,2n)196Au και 93Nb(n,2n)92mNb, για ενέργεια δέσμης νετρονίων 17.5 MeV. Η μονοενεργειακή δέσμη νετρονίων που χρησιμοποιήθηκε, παράχθηκε στον επιταχυντή Tandem Van der Graaf 5.5 MV του Ινστιτούτου Πυρηνικής Φυσικής του ΕΚΕΦΕ «Δημόκριτος», μέσω της αντίδρασης 3H(d,n)4He, χρησιμοποιώντας έναν καινούριο στόχο τριτίου κατασκευασμένο από ένα φύλλο Ti εμποτισμένο με αέριο τρίτιο, πυκνότητας 2.1 mg/cm2 , τοποθετημένο πάνω σε ένα φύλλο Cu πάχους 1 mm, για καλύτερη απαγωγή της θερμότητας. Για τη μέτρηση της ενεργού διατομής χρησιμοποιήθηκε ένας ραδιενεργός στόχος 241Am ενεργότητας 5.11 GBq, ο οποίος για λόγους ακτινοπροστασίας βρισκόταν κλεισμένος σε θωράκιση από Pb πάχους 3mm. Για τη μέτρηση της ενεργότητας των δειγμάτων μετά από την ακτινοβόληση, χρησιμοποιήθηκαν τέσσερις ανιχνευτές HPGe ονομαστικών αποδόσεων 100%, 100%, 50% και 16%. Η πειραματική μέτρηση της ενεργού διατομής, συνοδεύτηκε από προσομοιώσεις των πειραματικών συνθηκών με την τεχνική Monte Carlo. Από τις προσομοιώσεις προέκυψε η ροή των νετρονίων στο στόχο του 241Am κατά τη διάρκεια της ακτινοβόλησης και η απόδοση ενός από τους δύο ανιχνευτές HPGe ονομαστικής απόδοσης 100%, στον οποίο μετρήθηκε ο στόχος του 241Am πριν και μετά την ακτινοβόληση., The cross section of the reaction 241Am(n,2n)240Am, has been measured by the activation method, at neutron energy 17.5 MeV, relative to the 27Al(n,a)24Na, 197Au(n,2n)196Au, and 93Nb(n,2n)92mNb reactions reference cross sections. The monoenergetic neutron beam was produced at the 5.5 MV Tandem accelerator of NCSR Demokritos, by means of the 3H(d,n)4He reaction implementing a new Ti-tritiated target consisted of 2.1 mg/cm2 Ti-t layer on a 1 mm thick Cu backing for good heat conduction. The radioactive target consisted of a 5.11 GBq 241Am source enclosed in a Pb container. After the end of the irradiation, the activity induced by the neutron beam at the target and reference foils, was measured off- line by two 100%, a 50% and a 16% relative efficiency, HPGe detectors. In addition to the experimental measurements, the experimental set up has been simulated with the use of the MCNP code. By these simulations, the neutron flux in 241Am target during the irradiation and the absolute efficiency of the HPGe (100%) detector in which has been measured the 241Am target before and after its irradiation, have been estimated., Αντιγόνη- Γαρυφαλλιά Γ. Καλαμαρά

Systematic studies for the measurement of the cross section measurement of the ep -> e'X reaction and for the extraction of the proton structure function F2(x,Q2) are performed. The data sample analyzed has a luminosity of 450 nb sup(-1) and corresponds to a special data taking period taken in the year 2000, where the interaction point of the ep scattering was moved from its nominal position. In order to minimize the total systematic error of the measurement, detailed studies concerning the calibration of the main calorimeters of the H1 detector are required. Such studies and their influence on the cross section measurement are the main subject of the thesis. The kinematic region of the measurement has values of 9.5 x 10 sup(-6) < x < 8.0 10x sup(-3) and 0.2 < Q2 < 3.5 GeV2 and extends the kinematic coverage of the previous shifted vertex analysis based on data taken by the H1 detector in the year 1995. Also, the total systematic error is significantly reduced in comparison to the previous shifted vertex analysis.

Accelerator-driven systems for transmutation of nuclear waste have been suggested as a means for dealing with spent fuel components that pose potential radiological hazard for long periods of time. While not entirely removing the need for underground waste repositories, this nuclear waste incineration technology provides a viable method for reducing both waste volumes and storage times. Potentially, the time spans could be diminished from hundreds of thousand years to merely 1.000 years or even less. A central aspect for accelerator-driven systems design is the prediction of safety parameters and fuel economy. The simulations performed rely heavily on nuclear data and especially on the precision of the neutron cross section representations of essential nuclides over a wide energy range, from the thermal to the fast energy regime. In combination with a more demanding neutron flux distribution as compared with ordinary light-water reactors, the expanded nuclear data energy regime makes exploration of the cross section sensitivity for simulations of accelerator-driven systems a necessity. This fact was observed throughout the work and a significant portion of the study is devoted to investigations of nuclear data related effects. The computer code package EA-MC, based on 3-D Monte Carlo techniques, is the main computational tool employed for the analyses presented. Directly related to the development of the code is the extensive IAEA ADS Benchmark 3.2, and an account of the results of the benchmark exercises as implemented with EA-MC is given. CERN's Energy Amplifier prototype is studied from the perspectives of neutron source types, nuclear data sensitivity and transmutation. The commissioning of the n_TOF experiment, which is a neutron cross section measurement project at CERN, is also described.