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Study of reactions of simple ions in low temperature plasma
Kálosi, Ábel ; Plašil, Radek (advisor) ; Picková, Irena (referee)
The subject of this thesis is the study of the probe diagnostic method of low temperature plasma. The basis of Langmuir probe diagnostics in terms of appli- cation on apparatus CryoFALP II for the study of reactions of simply particles, the principle of the FALP technique and the experimental method of undertaken measurements are described. As a part of the thesis a package of evaluation pro- grams were compiled, which are ready to be a part of the measuring system as described in the thesis. Main results concern verification of the proper application of Langmuir probe technique in conditions characteristic for the apparatus, argon plasma was chosen as the medium of the measurements, where the characteristic loss process is ambipolar diffusion of charged particles. The application of the acquired knowledge is shown on recombination in oxygen plasma.
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Study of probe diagnostics of tokamak edge plasma via computer simulation
Podolník, Aleš ; Pánek, Radomír (advisor) ; Cavalier, Jordan (referee) ; Roučka, Štěpán (referee)
The aim of the thesis is to examine plasma-wall interaction using computer modeling. Tokamak- relevant plasma conditions are simulated using the particle-in-cell model family SPICE working in three or two dimensions. SPICE model was upgraded with a parallel Poisson equation solver and a heat equation solver module. Plasma simulation aimed at synthetic Langmuir probe measurements were performed. First set considered a flush-mounted probe and the effect of variable magnetic field angle was studied with aim to compare existing probe data evaluation techniques and assess their operational space, in which the plasma parameters estimation via fit to the current-voltage characteristic is accurate. Second simulation set studied a protruding probe pin. Effective collecting area of such probe was investigated with intentions of density measurement collection. This area was found to be influenced by a combination of two factors. First, the density dampening inside the magnetic pre-sheath of the probe head, and the second, the extension of the area caused by Larmor rotation. A comparison with experimental results obtained at COMPASS tokamak was was performed, confirming these results. Keywords Langmuir probe, simulation, particle-in-cell, tokamak, Poisson equation, COMPASS 1
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Probe diagnostics of the pulse-generated plasma
Turek, Zdeněk ; Tichý, Milan (advisor) ; Kaňka, Adolf (referee)
The subject of the bachelor thesis is the plasma diagnostics in the planar magnetron and in the hollow cathode system operating in the pulse mode, when the plasma is generated by DC pulses. The diagnostics method used will be the Langmuir probe. The aim of the thesis is the construction of the computer-controlled electronic measuring system and its assessment when measuring the parameters of argon discharge plasma in both systems with time resolution i.e. depending on time during one pulse period.
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Diagnostics of plasmas for technological applications
Turek, Zdeněk ; Kudrna, Pavel (advisor) ; Kousal, Jaroslav (referee)
The subject of the master thesis is the extension of the measurement of plasma para- meters by the Langmuir probe in a system with a planar magnetron and a hollow cathode operating in pulse mode. The main tasks are to modify the measuring circuit to increase the maximum probe current and to put the USB oscilloscope into operation for data collection with higher resolution and higher sampling rate. Furthermore, the function of the entire device will be verified using test circuits and also by measuring the probe characteristics in discharges in a system with a magnetron and a hollow cathode in both continuous and pulse mode. 1
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Diagnostics of plasmas for technological applications
Turek, Zdeněk ; Kudrna, Pavel (advisor) ; Kousal, Jaroslav (referee)
The subject of the master thesis is the extension of the measurement of plasma para- meters by the Langmuir probe in a system with a planar magnetron and a hollow cathode operating in pulse mode. The main tasks are to modify the measuring circuit to increase the maximum probe current and to put the USB oscilloscope into operation for data collection with higher resolution and higher sampling rate. Furthermore, the function of the entire device will be verified using test circuits and also by measuring the probe characteristics in discharges in a system with a magnetron and a hollow cathode in both continuous and pulse mode. 1
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Study of probe diagnostics of tokamak edge plasma via computer simulation
Podolník, Aleš ; Pánek, Radomír (advisor) ; Cavalier, Jordan (referee) ; Roučka, Štěpán (referee)
The aim of the thesis is to examine plasma-wall interaction using computer modeling. Tokamak- relevant plasma conditions are simulated using the particle-in-cell model family SPICE working in three or two dimensions. SPICE model was upgraded with a parallel Poisson equation solver and a heat equation solver module. Plasma simulation aimed at synthetic Langmuir probe measurements were performed. First set considered a flush-mounted probe and the effect of variable magnetic field angle was studied with aim to compare existing probe data evaluation techniques and assess their operational space, in which the plasma parameters estimation via fit to the current-voltage characteristic is accurate. Second simulation set studied a protruding probe pin. Effective collecting area of such probe was investigated with intentions of density measurement collection. This area was found to be influenced by a combination of two factors. First, the density dampening inside the magnetic pre-sheath of the probe head, and the second, the extension of the area caused by Larmor rotation. A comparison with experimental results obtained at COMPASS tokamak was was performed, confirming these results. Keywords Langmuir probe, simulation, particle-in-cell, tokamak, Poisson equation, COMPASS 1
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Probe diagnostics of the pulse-generated plasma
Turek, Zdeněk ; Tichý, Milan (advisor) ; Kaňka, Adolf (referee)
The subject of the bachelor thesis is the plasma diagnostics in the planar magnetron and in the hollow cathode system operating in the pulse mode, when the plasma is generated by DC pulses. The diagnostics method used will be the Langmuir probe. The aim of the thesis is the construction of the computer-controlled electronic measuring system and its assessment when measuring the parameters of argon discharge plasma in both systems with time resolution i.e. depending on time during one pulse period.
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Study of plasma-solid interaction by methods of computational physics
Palacký, Jakub ; Hrach, Rudolf (advisor) ; Novák, Stanislav (referee)
The diploma thesis is focused on the study of low-temperature plasma by methods of computational physics, namely particle modelling. The solution focuses on the time- effective execution of simulations, which is concerned, among the other things, with the use of parallelization techniques aimed at maximize shortening of the calculation time. The Langmuir probe was chosen as the most common representative of the probe diagnostics. The main goal of this work was to observe plasma interaction with the embedded solid. Current research on plasma modelling intensively explores dynamic phenomena such as wave propagation or turbulence and instability. For this reason, much of the work is devoted to the dynamics in electropositive and electronegative plasma.
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