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Effect of magnetic field on laser-induced plasma characteristics
Vrábel, Jakub ; Pořízka, Pavel (referee) ; Prochazka, David (advisor)
This work is based on topic of laser induced breakdown spectroscopy „LIBS“ and its application to chemical analysis of materials. Paper presents a brief theoretical basis of LIBS with focus on effect of magnetic field to plasmas and modeling spectras for calib-ration-free LIBS analysis. Considerable part of work is dedicated to practical demon-stration of modeling spectras, using Matlab and interpretation of experimental results. The final output is automatized method for evaluation of spectras, which could leads to calibration-free LIBS analysis. Also there is an effort to increase sensitivity of method.
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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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Computer modeling of plasma-material interactions: particle flow
ČERNÁ, Veronika
Bachelor thesis deals with computer modeling of the interaction of plasma with the surface of the solid material, primarily by determining the flow of electrically charged particles to the surface. The main emphasis lays on study of this phenomenon using COMSOL Multiphysics. After introductory chapter, in which is briefly characterized the fourth state of matter plasma, there is a chapter introducing the basic techniques of computer modeling. The third chapter presents software for technical calculations, the use of which is practically demonstrated in the next chapter by the example of the continuous modeling. The last part of the thesis forms a sample output of the model. Conclusion is the evaluation of the whole bachelor thesis and the possibilities of its further use.
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Numerical Calculations of MHD Equations in Solar Physics
PARANIAK, Marek
The subject of this bachelor thesis is the description of MHD ?Magnetohydrodynamic? equation and using for solar atmosphere activity modelling. It starts with brief description of history and background of development mathematical method used for numerical simulation. Furthermore mathematical algorithms used for most MHD modeling or simulation software. Next part of this thesis contain description of Athena 3.1 software structure and mainly its configuration under Linux system. Following part contains software structure description. Final part of this bachelor thesis shows some calculation examples and few visualization of software output
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Computer study of probe diagnostics in high-temperature plasma
Lachnitt, Jan ; Hrach, Rudolf (advisor) ; Kudrna, Pavel (referee)
Title: Computational study of probe diagnostics in high-temperature plasma Author: Jan Lachnitt Department: Department of Surface and Plasma Science Supervisor: prof. RNDr. Rudolf Hrach, DrSc., Department of Surface and Plasma Science Abstract: This work is concerned to the particle computer modelling of the interaction of plasma, especially edge plasma, with immersed solids, especially probes. First, the speed and accuracy of several algorithms of the electrostatic force calculation were compared. One of the algorithms has been newly proposed. Then, a two-dimensional model of the interaction of collision-less plasma with a probe was created. This model has been applied to experimental data from CASTOR tokamak. The crucial point of this work is the creation of a fully three-dimensional particle model. This model has been tested for accuracy and speed and has been parallelized for higher efficiency. Keywords: plasma, probe diagnostics, computational physics, particle modelling
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Waves and Oscillations in Solar Coronal Loops
BEDNÁŘ, Vít
Basic Sun characteristic, solar corona mainly. Introducing spacecrafts SoHO and TRACE as fundamental instruments of observing solar corona activities and close description this activities in therms of MHD theory. Recherche reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsion waves), theoretical modeling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.
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Theoretical modes of electric arc
Vondrák, Michal ; Šenk, Josef (referee) ; Lázničková, Ilona (advisor)
This thesis deals with theoretical models of the electric arc. Plasma arc and plasma torch are explained. Basic approaches of electric arc modeling are described. The indirect method for the determination of the mean temperature and velocity at the exit of plazma jet plasmatron are discussed. Finally the simplified model with axially-cooled electric arc is described.
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