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Computational study of metal film growth
Gabriel, Vít ; Hrach, Rudolf (advisor) ; Kučera, Michael (referee)
This thesis is focused on a design and an application of Monte Carlo method for simulation of the early stages of thin films growth. The obtained results were processed using morphological characteristics and compared with experimental data. The first part of this thesis is devoted to the mechanism of thin films growth, Monte Carlo method and a description of used morphological characteristics. In the second part of this thesis there are results obtained from the thin films growth simulation and results obtained from the use of morphological characteristics. In the end the Monte Carlo method was used for simulation of pulse deposition of thin films. Obtained results were again processed using morphological characteristics.
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Modelling of plasma-solid interaction
Nožka, Jan ; Hrach, Rudolf (advisor) ; Hron, Jaroslav (referee)
Title: Modelling of plasma-solid interaction Author: Jan Nožka Department: Institute of Theoretical Physics Supervisor: prof. RNDr. Rudolf Hrach, DrSc., Department of Surface and Plasma Science Abstract: This work is devoted to computer modeling of the low-temperature argon plasma discharge. We created one basic particle model and one basic fluid model. Furthermore, we created a model of electron-electron interaction in three dimensions. This model is able to stabilize nonequilibrium electron gas in the expected equilibrium. This model was developed to investigate the influence of electron-electron scattering on the acceleration of electrons above the speed that is sufficient for excitation or ionization of neutral argon atom. At the end of this work there are results that shed a light on the importance of this interaction in comparison with the amount of fast electrons that are present in the plasma due to electric filed field.
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Laboratory astrochemistry and applications of computer simulations
Roučka, Štěpán ; Hrach, Rudolf (advisor) ; Bonaventura, Zdeněk (referee) ; Novák, Stanislav (referee)
This work is focused on laboratory studies of ion chemistry at conditions relevant for astrophysics. The three main outcomes of the thesis are: (1) The experimental study of the reaction rate coefficient of the associative detachment reaction H- + H -> H2 + e-; measurement of the thermal rate coefficient at the temperatures in the range 10-135 K is described. (2) The design of a novel apparatus for detecting the electrons produced in the RF trap and measuring their energy; numerical simulations and preliminary experimental results are presented. (3) The development of a model of the electron cooling in the afterglow plasma and the application of the model in the analysis of the H3+ recombination measurements.
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Computational study of plasma-solid interaction in multicomponent plasma
Ibehej, Tomáš ; Hrach, Rudolf (advisor) ; Plašil, Radek (referee)
Physical processes ongoing during the interaction of both inert gas and chemically active plasma with surfaces of immersed solids are studied in this work. The technique used is a computer modeling based on experimental data obtained in our department and also taken from the literature. Focus of this work are two-dimensional particle simulations, whose outputs are parameters of a sheath formed around the immersed solid and characteristics of the contained charged particles. The study of multicomponent plasma presents an analysis of both statical and dynamical properties of the sheath depending on electronegativity. The research of influence of the computer modeling technique on the accuracy of the results and effi ciency of the computations is also accented.
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Study of plasma-solid interaction at medium pressures
Roučka, Štěpán ; Hrach, Rudolf (advisor) ; Novotný, Dušan (referee)
The thesis is aimed at particle simulation of plasma at medium pressures. Main results concern modelling of collisions in particle-in-cell algorithm. Dierent methods of modelling of collisions are discussed and their accuracy and eciency are investigated. Furthermore a new modication of particle-in-cell algorithm for modelling at medium pressures was proposed. Numerical benchmarks in the nal chapter show advantages of the new algorithm.
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Studies of tokamak edge plasma and its interaction with the first wall
Komm, Michael ; Kudrna, Pavel (advisor) ; Hrach, Rudolf (referee) ; Svoboda, Vojtěch (referee)
Title: Studies of tokamak edge plasma and its interaction with the first wall Author: Michael Komm Department: Department of Surface and Plasma Science Thesis director: doc. Mgr. Pavel Kudrna, Dr. KFPP Thesis supervisor: Dr. Renaud Dejarnac, IPP CAS CR Abstract: This work presents results of simulations of nuclear fusion related problems, using both 2D PIC code (SPICE2) and full 3D code (SPICE3). The simulations allowed us to predict particle and heat loads coming from plasma onto the divertor tiles, which is a key problem for the next-step de- vices. The results of simulations contributed to the research of fuel retention in the gaps between divertor tiles. We we also able to explain the behaviour of the Katsumata probe and verify the validity of its measurements. Keywords: Tokamak, PIC, divertor, tritium, Katsumata
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