Ph.D. Theses

Nowadays, the lithium-rich layered 3d-transition-metal (TM) oxides (LLOs) are regarded as one of the most attractive cathode materials for next-generation lithium-ion batteries (LIBs), because they can exhibit a discharge capacity (approaching 300 mAh g$^{-1}$ at 0.1 C) much higher than that of the currently used materials(~ 180 mAh g$^{-1}$at 0.1 C). However, the formation mechanism of LLOs has not been fully understood on a fundamental level yet.One of the most interesting and still open questionsis aboutlithium and oxygen atoms are incorporatedinto the precursor’s crystal structure during the synthesisoffinal LLO products.Asystematic exploration of this subject was conducted in this PhD work. [...]

This thesis deals with the polymerization-induced self-assembly (PISA) of amphiphilic blockcopolymer nano-objects, which were synthesized using a controlled radical polymerization(CRP) method, in particular, the reversible addition-fragmentation chain-transfer (RAFT)aqueous polymerization in the presence of a poly(N,N-dimethylacrylamide) stabilizer agent(macro RAFT agent). Besides the use of N-isopropylacrylamide (NIPAm) as core-formingblock for thermo-responsive nanoparticle, the aqueous dispersion polymerization of 2-methoxyethyl acrylate (MEA) was pursued as a model to study hydrophilic-hydrophobic phasetransitions: as a monomer, MEA is water-soluble. [...]

This thesis presents a study of the Standard Model (SM) Higgs boson in the decay channelof ! eμ, as well as a search for neutral Minimal Supersymmetric Standard Model (MSSM)Higgs boson in the same decay channel, using data corresponding to an integrated luminosityof 35.9 fb−1 in proton-proton collisions with a center-of-mass energy of 13 TeV, collected bythe CMS detector at the Large Hadron Collider. The results of eμ channel in both analysesare combined with other channels of Higgs to decay: eh, μh and hh.An observation of the SM Higgs boson to is established with a significance of 4.9 standarddeviations, to be compared to an expected significance of 4.7 standard deviations [...]

In this thesis we study the astrophysical implication of self-interacting dark matter. Observations on different scales suggest the existence of an additional form of matter which interacts gravitationally. [...]

This work considers the phase-space evolution of an externally injectedelectron beam under various plasma-based acceleration scenariosusing numerical methods.Plasma wakefield acceleration, an exceptional technology with thepotential to drive the next generation of particle accelerators, uses aparticle driver to excite a wakefield carrying gradients in the rangeof10 GV m−1to100 GV m−1, orders of magnitude higher than theconventional cavities currently available. However, the plasma envi-ronment has stringent requirements with respect to acceptable beamparameters which need to be carefully analyzed to enable stable beamtransport and acceleration. [...]

Despite its outstanding phenomenological successes, the Standard Model of particle physicshas a number of severe shortcomings. In this thesis, I address some of the most strikingof these. [...]

Instrumentation of higher order modes (HOMs) excited in accelerating cavities for beam phase and position inference provides a noninvasive and economical beam diagnostic. The principles and techniques for this purpose are investigated for TESLA (TeV Energy Superconducting Linear Accelerator) cavities at the injector part of the newly built European XFEL and at FLASH, two free electron laser facilities based on the TESLA technology.I have designed and instrumented unconventional beam phase monitors based on monopole modes in TESLA cavities and demonstrated a routine resolution of 0.1° with a broadband setup [...]

Ni-Ti shape memory alloys (SMA), have interesting functional properties such as shape memory effect and superelasticity that enable their use in different segments. These functional characteristics are obtained through the thermomechanical processing (hot and cold). [...]

The acceleration of electron beams in plasma wakefields driven by charged particlebeams is among the most promising candidates for future TeV-scale compact electronaccelerators. Currently available high energy proton beams that could serve as driverbeams in a plasma wakefeld accelerator (PWFA) are much longer than what is requiredfor efficient excitation of high-amplitude wakefields and thus for generating the desiredhigh acceleration gradients. [...]