In this bachelor thesis a feasibility study is carried out about assembling and programming a control unit for the 6 axis positioning robot EASy P1 series. The positioning robots will be used at DESY Research Center to adjust accelerator components. [...]

Seit Jahrzehnten wird das Ziel verfolgt, durch ein optimiertes Design Resonanz zu vermeiden, was für viele technische Bereiche – vor allem im Bereich Leichtbau – von großem Interesse ist. Ein Ansatz hierbei ist die Erhöhung (Maximierung) der Struktureigenfrequenzen. [...]

Free electron lasers (FELs) and high order harmonic generation (HHG) sources produce ultrafast coherent extreme ultraviolet (XUV) and X-ray radiation. These two powerful sources are optimal tools for time-resolved studies of ultrafast dynamics due to their high spatial and temporal resolution. [...]

A search for heavy, neutral Higgs bosons produced in association with b quarks and decaying into a pair of b quarks is presented. It is based on LHC Run 2 data, produced at a center-of-mass energy of 13 TeV in pp collisions and collected by the CMS experiment in 2017, corresponding to an integrated luminosity of 36.02/fb.Several theories beyond the Standard Model predict additional Higgs bosons and, dependingon the specific model, the coupling to b quarks can be significantly enlarged. [...]

This thesis presents the first evidence of Higgs boson decay to two leptons and a photon. Rare Higgsboson decays predicted in the Standard Model (SM) presently come within experimental reach thanksto the large amount of data collected by the experiments at the Large Hadron Collider (LHC) atCERN. [...]

This work covers two searches for exotic physics in proton-proton scattering atCERN's Large Hadron Collider, utilising data from the CMS experiment taken ata centre of mass energy of 13 TeV. The first analysis involves a search for DarkMatter in association with the decay products of a new scalar coupled exclusively tothe dark sector called the Dark Higgs. [...]

This work is dedicated to optimize and improve the machine learning techniques usedin the $\it H$ $\rightarrow$ $\tau \tau$ analysis in the channel where the tau leptons decay to a e $\mu$ pair. The measurement is performed using data, corresponding to an integrated luminosity of 59.7 fb$^{-1}$, collected by the CMS experiment at a center-of-mass energy of 13 TeV during 2018. [...]

In this doctoral thesis, possible solutions for superconducting cavity control systems operating in the Continuous Wave(CW) regime are discussed and analyzed. The paper focuses on the requirements for adding a CW mode of operationto European XFEL alongside the existing pulsed mode of operation. [...]

Water is commonly said to be the matrix of life. It is built from water molecules, which are connected via hydrogen bonds. [...]

Laser-plasma acceleration (LPA) [1] oers acceleration gradients several orders of magnitudehigher than in conventional radio-frequency accelerators, enabling the accelerationof electrons to hundreds of MeV in just a few millimetres. These small-scale acceleratorsand in particular X-rays generated from LPA electron beams could potentially be used inmaterial science or medicine [2]. [...]

Das IceCube Neutrino Teleskop hat einen diffusen Fluss hochenergetischen astrophysikalischen Neutrinos entdeckten. Allerdings sind die Quellen die für die Mehrzahl der nachgewiesenen Neutrinos verantwortlich sind, noch unbekannt. [...]

Der Betrieb des Teilchenbeschleunigers bei DESY in Hamburg stellt spezielle Anforderungenan Positioniergeräte für Sicherheits- und Analysemechanismen. AlsKonsequenz wurden verschiedene, auf diese speziellen Anforderungen optimierte,6-Achs-Kinematiken (vgl [...]

Conformal partial waves are fundamental objects in conformal field theory and their knowledge is a necessary prerequisite for the bootstrap programme. The study of partial waves is naturally a part of harmonic analysis on the conformal group. [...]

The discovery of the Higgs boson in 2012 by the CMS and ATLAS collaborations marked the start of the exploration of the Higgs sector of particle physics. This thesis explores one of these measurements: the study of the CP properties of the Yukawa coupling between the Higgs and the τ lepton. [...]

This thesis describes general strategies to directly study the electrochemical Liquid Liquid Solid (ec-LLS) growth process using a suite of in-situ characterization techniques. The central goal of this work is to directly observe the ec-LLS process as it occurs to increase our understanding of the fundamental aspects of the technique.The first portion of this thesis details a general methodology for the study of electron beam stimulated ec-LLS nanowire growth via liquid cell transmission electron microscopy (LC-TEM). [...]

Despite the great successes achieved by the Standard Model (SM) in explaining and predicting the behavior and existence of particles, multiple phenomena are yet to be given a satisfying explanation. Amongst these is Dark Matter (DM), a kind of matter that would permeate the whole Universe and that so far has been observed only via its gravitational interactions.One possible extension of the SM, which may contribute to solve the mystery of DM and/or explain some astrophysical anomalies, are Axion-Like Particles (ALPs). [...]

Diese Arbeit beschreibt die Suche nach assoziierter Produktion eines Higgsbosons und eines Top-Quark Paares in Proton-Proton Kollisionen bei einer Schwerpunktsenergie von 13 TeV. Für diese Analyse wurden Ereignisse analysiert, die exakt zwei Leptonen mit gleichem Ladungsvorzeichen oder exakt drei Leptonen enthalten und daher auf die Higgs Zerfallsmoden in H->WW, H->ZZ und H->tautau sensitiv sind. [...]

Many models of dark matter place their dark matter candidate inside a broader dark sector with other particles and fields for theoretical and phenomenological reasons. The cosmological evolution of these dark sectors can differ significantly from standard scenarios, in particular due to their interplay with the Standard Model of particle physics. [...]

The Free Electron Laser in Hamburg FLASH provides short X-Ray and ultraviolet pulses with high repetition rates in bursts. Optical laser systems create synchronized bursts in various wavelength ranges for pump-probe-experiments. [...]

An important part of research and development (R&D) in the field of superconducting radiofrequency cavities is quench detection since these local breakdowns of superconductivity primarilylimit the cavity performance. Due to the detection of second sound waves propagating inliquid helium, the localization of quench spots on superconducting radio frequency cavities no longer requires the laborious attachment of many temperature sensors. [...]

The deformation and failure behavior of rubbers is significantly influenced by the chemical composition and loading conditions. Investigations on how loading parameters, such as strain rate or type of loading, e.g. [...]

X­ray beam induced current (XBIC) and laser beam induced current (LBIC) measurements en­able the point by point correlation of solar cell performance with complementary measurementmodalities in scanning microscopy.In this Bachelor’s thesis a complete mini­module with a mono­crystalline silicon solar cell in­cluding housing was measured using a 28keV X­ray beam and a 532nm laser beam as a probe.In particular, the influence of an Ag finger front contact on the multi­model signals induced bythe two measurement probes was compared.The hard X­ray photons were nano­focused and the energy was chosen that the beam can pene­trate the complete module and excite the AgK electrons in the Ag fingers. The strong absorptanceof the Ag fingers can be clearly seen in the X­ray transmittance measurements. [...]

Hard X-ray full-field nanotomography is an ideal technique to study the inner structureof materials non-destructively at high spatial resolution, covering research areas suchas material science, biology and medical research. In particular, in situ experiments areof high importance to study dynamics and processes in materials. [...]

In order to meet the increasing need for energy storage systems in consumer devices, electric vehicles and stationary energy storage devices, the existing battery technologies are constantly being further developed. An important criterion for the performance of the battery is its energy density. [...]

Nano-bainitic steels represent a new class of alloys, whose microstructure consists of nanostructured bainitic ferrite formed at low temperature with a high amount of retained austeniteleading to a high ductility and high tensile strength of the steel. Formation of nanobainite has been studied thoroughly in literature as well as tempering of nano-bainitic steels. [...]

In x-ray quantum optics, many experimental schemes and techniques that are widelyused at visible frequencies are hard to implement. Key difficulties are the measure-ment of complex phases on the detection side and temporal pulse shaping on the lightsource side. [...]

In the light of upcoming gravitational wave experiments like the Laser Interferometer SpaceAntenna (LISA) we aim to improve the understanding of early universe first-order phasetransitions.In this thesis, the central subject of study is the energy budget of phase transitions. Thisthermodynamic quantity can be studied microscopically in equilibrium finite temperaturequantum field theory. [...]

The field of γ-ray astronomy opened a new window into the non-thermal universe that allows studying the acceleration sites of cosmic rays and the role of cosmic rays on evolutionary processes in galaxies. The detection of almost one hundred Galactic very-high-energy (VHE: 0.1−100TeV) γ-ray sources in the Milky Way demonstrates that particle acceleration up to tens of TeV energies is a common phenomenon. [...]

Mini-ferritins also known as Dps (DNA-binding protein from starved cells) belong to the ferritin family. They are composed of 12 identical subunits forming a hollow quasi spherical structure with 9 nm outer diameter and 5 nm inner diameter. [...]

Free-electron lasers (FELs) are the fourth generation of synchrotron light sources operating in the ultraviolet and X-ray wavelength range. The large size and the high costs of such sources limit the handiness of them. [...]

Molecular transformations triggered by the absorption of light are of tremendous importance in our day-to-day life, science, and technology. Examples of such "photo-induced" reactions include, among many others, photosynthesis, solar energy conversion, and mechanisms behind human vision [...]

Laser beam induce current (LBIC) and X­ray beam induced current (XBIC) are effective tech­niques for mapping the spatial electrical performance of solar cells. Conducting precise currentmeasurements up to the femto­Ampere range is challenging and susceptible to noise [...]

In this thesis a nano-electrospray ionization source gets developed. Since nano-electrosprayionization has an increasing importance for single particle imaging we want to optimizethe developed nano-electrospray ionization source for single particle imaging applica-tion. [...]

In the search for physics beyond the Standard Model, research in particle physics aims to probe particle interactions at high energies and strives for better precision on measurements. Experiments such as Belle II target higher luminosities to push the precision frontier. [...]

In this work, the temperature-dependent phase behavior and the structural transitions of novel thermoresponsive homopolymers and the self-assembly behavior of amphiphilic diblock copolymers are studied in aqueous solution by scattering methods, also with respect to the effect of methanol..

Understanding the interaction of matter with ultrashort attosecond light pulse provides fundamental insights into the structure of matter. The electronic properties are reflected in wave packets dynamics. [...]

Kesterite type materials are researched for their ability to form thin film solar cell absorbers from earth abundant and non-toxic elements. Main routes to increase their efficiencies to the level of competing materials include compositional variations such as deviations from stoichiometry and alloying. [...]

In this thesis, a new method of performing total X-ray scattering measurements of photo-electrochemically (PEC) active CuBi2O4 thin-films in operando was investigated. The thin-films were fabricated via spin-coating of a precursor solution containing Cu and Bi ions onto an FTO-coated glass substrate. [...]

For more than 40 years, most astrophysical observations and laboratory studies of two key soft X-ray diagnostic 2p-3d transitions, 3C and 3D, in Fe XVII ions found oscillator-strength ratios $f_{3C}/ f_{3D}$ disagreeing with theory. This discrepancy hampered the proposed plasma diagnostic utility based on the observed intensity ratios ever since [...]

In this thesis, a theoretical framework for x-ray cavity QED with Mössbauer nuclei is developed. First, it is shown how Jaynes-Cummings-like few-mode models for open resonators can be derived from first principles, which has been an open question in the quantum optics literature [...]

The upcoming generation of hard X-ray free-electron lasers (XFEL) delivers X-raypulses with unmatched brilliance at megahertz repetition rates based on supercon-ducting linear accelerators. The European XFEL, the first XFEL of this generation,accelerates bursts of up to 2700 electron bunches every tenth of a second over adistance of 1.7 km to energies as high as 17.5 GeV. [...]

Filamentous fungi are fo high biotechnological interest. Their fermentation products can beused for producig various goods. [...]

Simulation is essential to high-energy physics. The application of simulation ranges from development of software to the analysis of physical processes. [...]

The High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes located in the Khomas Highland of Namibia. H.E.S.S. [...]

In this thesis the development of a time projection chamber (TPC) for the International Large Detector (ILD) concept at the International Linear Collider (ILC) is discussed and an analysis is carried out to evaluate the performance of the detector concept. The ILC is a planned linear electron-positron collider. [...]

The aim of this work was to explore the potential of a combined rheology and X-ray scattering approach on complex fluids. Shear rates between 0.9·10$^5$ s$^{−1}$ and 5.6·10$^5$ s$^{−1}$, which are magnitudes higher than found in classical rheometry studies, were applied to a suspension of colloidal silica nanoparticles by a microfluidic jet device. [...]

In this thesis, photoelectron spectroscopy in combination with extreme-ultraviolet (XUV) and infrared (IR) radiation is employed to investigate non-linear effects in rare gas atoms. Electrons are measured by means of a reaction microscope which allows to determine the particles’ momentum vector in 4π solid angle [...]

Investigating the physical properties of minerals at extreme pressures and temperatures is crucial for understanding the interior structure of planetary bodies and unravelling their formation and evolution. Earth’s interior is characterized by hosting an iron-rich core enveloped by a mantle with a composition dominated by MgSiO$_3$ and (Mg,Fe)O. [...]

Aligning the gratings of an optical compressor for femtosecond pulses, as used inchirped pulse amplification, is a nontrivial task. In order to simplify this task a portabletunable continuous-wave laser, with automated wavelength tuning, was designed, constructedand automated. [...]

Recent discoveries in the area of cosmology, like the proposition of dark matter, haveindicated that there may be additional particles beyond the Standard Model which mayexplain the phenomena of Dark Matter in the Universe. Among many suggestions ofwhat Dark Matter actually is, there are models such as two-Higgs doublet Models thatpredict the existence of additional scalar (H) or pseudoscalar (A) Higgs bosons whichcould function as mediators between Standard Model and Dark Matter particles. [...]

The LHC precision program aims to more thoroughly test the Standard Model of particle physics than ever before. Precise theory predictions for realistic experimental observables are a key ingredient in this program. [...]

Filamentous fungi are responsible for a large number of products in biotechnology and are characterizedby advantages such as easier product purification and often higher yields in comparisonto bacteria. Nevertheless, their complex morphological structure poses major challengesfor the industry. [...]

This thesis presents work for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). The two main subjects are a search for Dark Matter events in final states with one lepton within two supersymmetry (SUSY) models and studies on the performance of the Hadron Outer (HO) calorimeter as a support for the muon system and the muon trigger. [...]

The achievable resolution in hard X-ray microscopy is limited by inherent lensaberrations, which makes the characterization of wavefront aberrations a criticaltask for pushing the limits of microscopy. The main goal of this thesis is to developand employ techniques to test state-of-the-art X-ray optics. [...]

Die Entdeckung des Higgs-Bosons im Jahr 2012 bestätigt das Standardmodell als die erfolgreichste Theorie, die die grundlegenden Wechselwirkungen von Elementarteilchen beschreibt. Eine der wichtigen Eigenschaften des Higgs-Bosons ist seine Yukawa-Kopplung an das Top-Quark, die aufgrund der hohen Masse des Quarks im Standardmodell am stärksten ist. [...]

In the present thesis, the Group 13 metals, gallium, indium and aluminium, are investigated with a focus on the structures of the ions in solution and the formationof their oxides during solvothermal synthesis. The Group 13 metal oxides are am chemical similar group of materials, which all form the species M2O3, MOOH and M(OH)3. [...]

In this thesis a scheme to measure the slice emittance of a high-brightness electron beam which undergoes space charge effects is developed and employed. For this, a transverse deflecting structure (TDS) is added to the single-slit scan technique, which is used at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) to measure projected emittance. [...]

This work investigates the growth dynamic of the reactive molecular beam epitaxy of Fe$_3$O$_4$ films, and its impact on the cation distribution as well as on the magnetic and structural properties at the surface and the interfaces. In order to study the structure and composition of Fe$_3$O$_4$ films during growth, time-resolved high-energy x-ray diffraction (tr-HEXRD) and time-resolved hard x-ray photoelectron spectroscopy (tr-HAXPES) measurements are used to monitor the deposition process of Fe$_3$O$_4$ ultrathin films on SrTiO$_3$(001), MgO(001) and NiO/MgO(001). [...]

Current work is devoted to synthesizing and studying atomic and electronic structure of several low-dimensional carbon-based nanomaterials, which can be of interest for fabrication of advanced electronic devices. All of them exhibit a $\pi$-conjugated structure, which promises high stability and endurance in the case of employment in technological applications. [...]

The Standard Model of particle physics stands as one of the triumphs of the20th and 21st century so far. Colliders around the world have been built for thepurpose of pushing this theory to its limit, and have consistently found theirmeasurements to be well described. [...]

In this work, the implementation of an XUV-pump–XUV-probe transient absorption spectroscopy scheme at the free-electron laser facility FLASH in Hamburg is presented. It is applied to the ultrafast dissociation dynamics of the small molecules diiodomethane and oxygen. [...]

Silicon sensors are widely used in HEP experiments for particle tracking and calorimetry. One of the problems of silicon detectors is the increase of leakage current due to radiation damage. [...]

This thesis deals with the impact of ultrashort near-infrared~(nIR) and extreme ultraviolet~(XUV) laser pulses on the magnetic multi-domain states of particularly thin Co/Pt multilayers. The laser induced magnetization dynamics are investigated with femtosecond time and nanometer spatial resolution utilizing time-resolved magnetic small-angle X-ray scattering~(TR-mSAXS) at the free-electron lasers~(FEL) FLASH in Hamburg and FERMI@Elettra in Trieste.One part of the thesis deals with ultrafast demagnetization in three different Co/Pt-multilayer samples with total film thicknesses in the range of the attenuation length of nIR radiation in Co and Pt. [...]

The results obtained at the LHC agree well with the predictions of the Standard Model of particle physics (SM). However, the need for Beyond the Standard Model (BSM) physics remains. [...]

Single-particle diffractive imaging at x-ray free-electron lasers is a promising technique for reconstructing the three dimensional structure of biomolecules such as proteins or viruses, avoiding drawbacks of conventional diffractive imaging methods, such as the need of crystalline sample. In order to achieve atomic resolution a huge amount of diffraction patterns of identical particles, ideally in gas phase are needed. [...]

Despite strong indications for physics beyond the Standard Model (BSM), no definitedirect detection of new physics has been made at the Large Hadron Collider (LHC)yet. Therefore, high-precision particle physics becomes ever more important in orderto probe the Standard Model (SM) parameters for any deviation from theoreticalpredictions.This requires increasing experimental precision and theoretical accuracy. [...]

The first two decades of this century mark the beginning of the precision cosmologyand astrophysics era. Two remarkable cosmological results include the measurementsof the cosmic microwave background (CMB) anisotropies by the Planck satellite andof the baryonic acoustic oscillations (BAO) by the Sloan Digital Sky Survey. [...]

This thesis provides a growth study of α-Al2O3(0001) supported Pt particles and subsequent structure monitoring using ensemble and single-particle X-ray diffraction (XRD) during catalytically driven CO oxidation on PtRh particles.The growth study provided two different particle morphologies dependent on the type of annealing after epitaxial growth at 830 °C using molecular beam epitaxy (MBE) in ultra high vacuum (UHV): annealing of particles at 1100 °C in UHV yielded (111)-oriented, flat particles with a height of about 4 nm and an average diameter of about 20 nm (surface coverage about 40 %). In turn, upon exposure to air at 1200 °C, the nanoparticles undergo a redistribution of the deposited material with the coverage significantly decreased to 7 %, likely via the formation of metastable PtOx species [...]

After the Higgs boson discovery by the ATLAS and CMS collaborations at CERN, one of the main goals of the Large Hadron Collider programme is to find Beyond the Standard Model particles. This thesis focuses on the search for supersymmetric partners of the leptons (sleptons) and presents the prospects of a search for the supersymmetric partners of the electroweak gauge bosons and the Higgs boson (higgsinos). [...]

A phenomenology study and a differential cross-section measurement are presented in this thesis.For the phenomenology study, the differential cross-sections of the top quark pair production in association with a Higgs boson ($t\bar{t}H$) are calculated with the top quark running mass in the $\overline{MS}$ renormalization scheme for the first time.The cross-sections and their scale uncertainties are calculated as a function of the kinematic variables of the top quarks, the Higgs boson, the top quark anti-quark system, and the invariant mass of the $t\bar{t}H$ system.Subsequently, the results are compared to calculations in the pole mass scheme.Overall, the scale uncertainties in the calculations using the $\overline{MS}$ scheme are found to be slightly reduced compared to the pole mass scheme.The second study presented in this thesis is the total and differential cross-section measurements of the top quark pair production with additional jets originating from the hadronization of bottom quarks ($t\bar{t}+b-\text{jets}$ ) in the dilepton decay channel of the $t\bar{t}$ system at the center-of-mass energy $\sqrt{s}=13$ TeV.The analysis is performed using data recorded by the CMS detector in the Run II period of the LHC during the years 2016, 2017, and 2018, corresponding to an integrated luminosity of $137.19 ~\text{fb}^{-1}$.The measurement of the total production cross-section of the $t\bar{t}+b-\text{jets}$ process is the most precise to date and the value is found to be $\sigma_{t\bar{t}+b-\text{jets}} = 4.91\pm0.08(\text{stat})^{+0.47}_{-0.43}(\text{sys})$ pb.The absolute and normalized differential cross-sections are measured as a function of transverse momentum, the absolute value of the pseudo-rapidity, the invariant mass, and the distance of the additional $b$-jets.For the first time, the differential distributions of the sub-leading additional $b$-jet are measured at $\sqrt{s}=13$ TeV.Additionally, two top quark definitions are used to define the additional $b$-jets at the truth level: a parton-based and a purely particle-based approach.The results are compared to the state-of-the-art Monte Carlo simulations of the $t\bar{t}+\text{jets}$ and $t\bar{t}+b-\text{jets}$ processes.Overall, all simulations are found to describe the measured normalized distributions similarly well.However, the absolute differential cross-sections are best described by the Powheg+Openloops+Pythia8 and the PowHel+Pythia8 (5FNS) $t\bar{t}+b-\text{jets}$ simulations..

The $7^{\text{th}}$ harmonic generation of $1030\,\text{nm}$ light constitutes a rather unexplored regime within the field of harmonic generation. The resulting coherent light with a wavelength of roughly $150\,\text{nm}$ can be utilized for a wide range of novel applications, in particular the recently emerging field of nuclear spectroscopy of the Thorium-229 isotope nucleus. [...]

Plasma wakefields enable GeV/m-level acceleration gradients, making them a promising avenue to reduce the size and the associated costs of future particle accelerators. High-energy physics facilities in particular place stringent demands on beam quality and energy efficiency, which necessitates precise control of the beam acceleration. [...]

The electronic structure of biomolecules is, in combination with the geometric structure, crucial for their functionality. However, the electronic structure is challenging to assess experimentally due to the high complexity of these large molecular systems. [...]

X-ray microscopy is characterized by its high spatial resolution, exceeding that ofvisible light microscopy, while also being able to penetrate thick samples and sample enclosures that are inaccessible to electron microscopy. With these characteristics, x-ray microscopy excels in in-situ imaging of nanoscopic sample systems that are highly relevant in fields such as chemistry and life sciences.Ptychography is a lensless, computational microscopy technique in which the objective lens of the microscope is replaced with an algorithm to retrieve the phases of the coherent wave field. [...]

This thesis presents measurements of multi-differential top quark pair (t ̄t) production cross sections in pp collisions at the LHC with a centre-of-mass energy of 13TeV using events containing two opposite-sign leptons. The analyzed dataset was recorded with the CMS detector in the years 2016, 2017 and 2018, and corresponds to an integrated luminosity of 137 fb−1.Precision double- and triple-differential cross sections are measured as a function of observ- ables describing the kinematic properties of the top quark, top antiquark, and t ̄t system, for both parton and particle level definitions of these objects. [...]

The investigation of light-matter interactions is based on the description of the ‘photoelectric effect’ in the early 20th century. The development of the first laser systems, especiallyof systems with high intensities and/or high photon energies allowed science to enter new interaction regimes. [...]

In dieser Dissertation wird die Suche nach schweren neutralen pseudoskalaren A und skalaren H Higgs-Bosonen vorgestellt, die in gg-Fusionen erzeugt werden, und in ein Top-Antitop-Quark-Paar zerfallen. Gesucht wurde im vollständigen Datensatz von Proton–Proton-Kollisionen bei einer Schwerpunktsenergie von 8 TeV die vom ATLAS-Detektor am Large Hadron Collider aufgezeichnet wurde und einer integrierten Luminosität von 20.3 fb$^{−1}$ entspricht. [...]

The subject of this thesis is the development and test of silicon strip detectors for thehigh luminosity upgrade of the tracking detector of the ATLAS experiment at the LargeHadron Collider. Special emphasis is devoted to the understanding of the impact ofmechanical stress on the electrical properties and the particle detection performance ofdetector modules.First simulations were done to estimate the maximum expected stress on a sensor whenoperated at -30 ◦C within the future silicon strip tracking detector ITk, at ATLAS. [...]

In this thesis the dynamics and higher order correlations of different colloidal sample systems are investigated at various volume fractions near the glass transition. Two different hard sphere and a charge stabilized system were studied [...]

Obwohl etwa 85% der gesamten Materie im Universum aus Dunkler Materie besteht (vgl.Eidemüller 2017: 5), ist ihre Natur bisher noch ungeklärt. Lediglich die Gravitationswirkung, die Dunkle Materie auf sichtbare Materie zu hab en scheint, ist erwiesen. [...]

In various astrophysical observations, the n = 2 → 3 transitions of highly charged iron appear in the soft x-ray region as an unresolved transition array (UTA). The structure of the UTA is directly related to the ionization balance of the plasma and is therefore of high astrophysical interest. [...]

When materials are fabricated at the nanoscale, properties such as thermodynamic quantities can drastically deviate from bulk properties. Thereby, the embedding environment has a strong impact on the behavior of the nanostructured material and thus provides a handle to engineer the properties as desired. [...]

FLASH (Free Electron Laser in Hamburg) is a linac based SASE (Self-AmplifiedSpontaneous Emission) FEL (Free Electron Laser) facility generating high qualityEUV (Extreme Ultra-Violet) to soft X-ray radiation pulses. TESLA (TeV EnergySuperconducting Linear Accelerator) 1.3 GHz cavities are used for the accelerationof the electron bunches. [...]

The Belle II experiment, located at the SuperKEKB e+e- collider inJapan, uses pulse shape analysis techniques to distinguish electromagneticallyand hadronically interacting particles within the CsI(Tl) electromagneticcalorimeter. The pulse shapes from the particle-dependent scintillationresponse are nominally analysed with a multi-template oine t to measurethe fraction of scintillation emission produced by hadrons [...]

Biological cells are the basic structural and functional units of all organisms. There are approximately 60 trillion eukaryotic cells within a human body alone. [...]

The SINBAD (Short INnovative Bunches and Accelerators at DESY) facility at DESY is a dedicated acceleratorresearch and development project for the production of ultra-short electron bunches and development of novelhigh gradient accelerator technology. The ARES linac (Accelerator Research Experiment at SINBAD) is therst infrastructure implemented at SINBAD and has a focus on the generation and characterization of ultra-short, small emittance electron pulses, ultimately aiming at the few femto-second regime. [...]