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Study of organosilicone fragmentation in plasma
Sahánková, Hana ; Studýnka, Jan (referee) ; Krčma, František (advisor)
This Bachelor Thesis deals on the study of organosilicone monomers in plasma. The dimethylphenylsilane (DMPS) was chosen as the organosilicone example. The theoretical part gives basic overview of plasmachemical processes and technologies used in present world. Some part is reserved for the description of plasma diagnostic basic methods as optical emission spectroscopy and mass spectroscopy. The experimental part is constituted from two different experiments. The first one was done as model experiment of DMPS fragmentation by electron beam of exact energy and it was completed at Faculty of Mathematics, Physics and Informatics in Bratislava. Results of these experiments brought a set of electron energies needed for the creation of various ionic fragments from the original molecule as well as the cross sections for their creation. The second part of the experiments was carried out under the inductively coupled RF low pressure plasma conditions during the deposition of DMPS based thin films. The plasma was monitored by optical emission spectroscopy at different discharge power. Various species were identified in the spectra. The calculation of plasma parameters and their comparision with the model experiment data will be subjects of the further work.
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Investigation of Nuclear Power-Reactor Core Poisoning
Janošek, Radek ; ČR,, Milan Štefánik, Ústav jaderné fyziky AV (referee) ; Katovský, Karel (advisor)
The aim of this Bachelor´s Thesis is to characterize fundamental transient processes, which takes place in nuclear power-reactor. The main goal is the theoretical analysis of these processes, which include xenon poisoning, samarium poisoning, xenon after shutdown, xenon oscillation, and permanent poisoning. A significant part of the thesis deal with the simulation of xenon poisoning and samarium poisoning. Model was created using Maple software. One of the other points is to state the basic concepts of nuclear physics and also to describe nuclear power-reactor primary operating processes.
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Simulation of nuclear fuel burn-up during whole fuel cycle
Smola, Luděk ; ČEZ,, Ondřej Zlámal, (referee) ; Katovský, Karel (advisor)
The main goal of this Bachelor’s thesis is to create a long-term kinetics model of a nuclear reactor – model, which simulates changes in nuclear fuel inside the reactor core during reactor operation. As the term long-term suggests, primarily the changes in whole five-year fuel cycle horizon are studied, which stands for changes in concentration of elements contained within fresh fuel as well as origination of new ones (with special focus on higher actinides and plutonium). This mathematical model is created using the MAPLE 14 software. Outputs from the model are displayed graphically and thoroughly analysed, so that comprehensive conclusions of problems can be made. Furthermore, the thesis contains theoretical and informational background that is necessary for understanding all the aspects of the model – historical development of nuclear reactors, their basic types, nuclear fuel description focusing on fuel for pressurized light-water reactors VVER (for which the model is primarily designed), MOX fuel and possibilities of its utilization, and last but not least – selected topics from nuclear physics.
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Transmutation of spent nuclear fuel with using accelerator driven systems
Máca, Pavel ; Král, Dušan (referee) ; Zeman, Miroslav (advisor)
This bachelor thesis deals with the analysis of neutron spectra in the reactors with liquid salts. The teoretical part contains a brief description of the nuclear fuel cycles. In the theoretical are further described the reactors of IV. generations. Here are the reactors on the basis of liquid salts described in detail. The practical part of the bachelor thesis is focused on the analysis of neutron spectra in set-ups performer from solid salt. Concretly, the salts NaCl and KCl were analysed by means of the computational codes TALYS and MCNP.
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Determination of nuclear reactions' microscopic cross-sections using an accelerator-driven neutron source
Filová, Vendula ; Šťastný, Ondřej (referee) ; Král, Dušan (advisor)
Tato práce se věnuje určení mikroskopických účinných průřezů interakcí neutronů s indiem. Teoretická část shrnuje neutronové zdroje používané ve vědě i průmyslu, popisuje princip jejich fungování a představuje příklady jejich aplikací. Praktická část obsahuje postup vyhodnocování velikostí účinných průřezů včetně jednotlivých provedených korekcí. Byly vyhodnocována data celkem ze tří experimentů, při kterých byly produkovány neutrony interakcí protonů s tenkým lithiovým terčem. Kvazi monoenergetickým neutronům byly vystaveny sendviče folií včetně foile z india, produkty interakcí byly měřeny pomocí gamma spektrometrie. Výsledné mikroskopické účinné průřezy jsou porovnány s daty z knihoven evaluovaných dat a z knihovny EXFOR.
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Family house load-carrying structure composed of thin-walled cold-formed steel profiles
Jančar, Ondřej ; Melcher, Jindřich (referee) ; Karmazínová, Marcela (advisor)
The aim of the bachelor thesis is make a structural design of prefabricated family house. The load-carrying structure is composed of thin-walled cold-formed steel profiles. The family house is single-storey without basement. The object has rectangular ground plan with proportions of 9 x 14 m. The gable roof has slope 27°. Roof truss girders allows to make a attic space for storage seasonal things. The house is situated in city development of Bílovec. The object was designed according to currently valid standarts to the ultimate limit states and seviceability limit states.
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Determination of nuclear reactions' microscopic cross-sections using an accelerator-driven neutron source
Filová, Vendula ; Šťastný, Ondřej (referee) ; Král, Dušan (advisor)
Tato práce se věnuje určení mikroskopických účinných průřezů interakcí neutronů s indiem. Teoretická část shrnuje neutronové zdroje používané ve vědě i průmyslu, popisuje princip jejich fungování a představuje příklady jejich aplikací. Praktická část obsahuje postup vyhodnocování velikostí účinných průřezů včetně jednotlivých provedených korekcí. Byly vyhodnocována data celkem ze tří experimentů, při kterých byly produkovány neutrony interakcí protonů s tenkým lithiovým terčem. Kvazi monoenergetickým neutronům byly vystaveny sendviče folií včetně foile z india, produkty interakcí byly měřeny pomocí gamma spektrometrie. Výsledné mikroskopické účinné průřezy jsou porovnány s daty z knihoven evaluovaných dat a z knihovny EXFOR.
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Use of activation detectors for neutron field measurement in models of ADTS
Chudoba, Petr
Accelerator driven transmutation systems could be a solution to the problem with long-lived nuclear waste and opening the way to thorium fuel cycle. Due to intensive neutron source based on spallation reaction are these systems very litle dependent on the arrangement of the core and fuel quality. These systems can transmute the spent fuel, eventually 232Th or 238U without affecting maintenance of fission reaction. Additionally subcritical blanket ensures high safety. For these systems it is necessary to know the cross sections of reactions of fast neutrons produced in the spallation reaction with different materials. This data is necessary not only for the selection of appropriate construction materials, but also for creation of programs simulating accelerator driven transmutation systems. This thesis is focused on the experimental determination of cross sections of reactions 89Y(n,2n)88Y and 89Y(n,3n)87Y with neutron energies from 17,6 to 33,6 MeV. Yttrium is analyzed for its (n,xn) threshold reactions, which makes it appropriet activation detector for study of the neutron fields in model configurations of accelerator driven transmutation systems. The obtained cross sections are unique, in that so far there are no experimental data for used neutron energies. Powered by TCPDF (www.tcpdf.org)
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Calculations of photoelectron spectra of small water clusters using the independent molecule model
Šklíba, Pavel ; Mašín, Zdeněk (advisor) ; Čížek, Martin (referee)
The aim of this thesis is to investigate theoretically photoelectron spectra of small water molecular clusters. This work is motivated by the recent experimental results of Hartweg et al [Phys. Rev. Letters 118, 103402, 2017] which showed that with an increasing number of constituent molecules in the water cluster the asymmetry parameter characterizing the photoelectron angular distribution converges to a universal shape. At the moment there are no theoretical calculations to support this finding. Therefore, we have developed a very simple model of photoionization of molecular clusters based on the use of photoionization data for a single molecule. We have found that the results of our model are sensitive to the different conformations of the clusters. Some of our results for the photoelectron angular distribution exhibit trends observed in the experiment. Nevertheless, the validity of our model will have to be studied in the future with the help of accurate calculations before the results can be conclusively interpreted.
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Transmutation of spent nuclear fuel with using accelerator driven systems
Máca, Pavel ; Král, Dušan (referee) ; Zeman, Miroslav (advisor)
This bachelor thesis deals with the analysis of neutron spectra in the reactors with liquid salts. The teoretical part contains a brief description of the nuclear fuel cycles. In the theoretical are further described the reactors of IV. generations. Here are the reactors on the basis of liquid salts described in detail. The practical part of the bachelor thesis is focused on the analysis of neutron spectra in set-ups performer from solid salt. Concretly, the salts NaCl and KCl were analysed by means of the computational codes TALYS and MCNP.
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