|
|
Application of methods of computational physics for the study of plasma-solid interaction
Hromádka, Jakub ; Hrach, Rudolf (advisor) ; Novák, Stanislav (referee)
Low-temperature plasma and its interaction with immersed solids is studied in this work. The research of the physical processes on this interface is performed by two-dimensional particle computer model. The model uses molecular dynamic method. Mutual forces between particles are computed by Particle- in-Cell method. The main application of the model is in the area of the probe diagnostic of plasma. Simple problems are compared with theory and two dimensional effects are discused. Contribution of particle modeling to plasma research is showed on the problem of interaction of sheaths around cylidrical probes. We deal with question whether we are able to get some information about unevennesses at the surface of solid immersed in plasma by measuring probe characteristics in its surroundings. We also studied the influence of plasma electronegativity on the parameters of sheaths around cylidrical probes. Powered by TCPDF (www.tcpdf.org)
|
|
|
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
|
|
|
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
|
|
|
Application of methods of computational physics for the study of plasma-solid interaction
Hromádka, Jakub ; Hrach, Rudolf (advisor) ; Novák, Stanislav (referee)
Low-temperature plasma and its interaction with immersed solids is studied in this work. The research of the physical processes on this interface is performed by two-dimensional particle computer model. The model uses molecular dynamic method. Mutual forces between particles are computed by Particle- in-Cell method. The main application of the model is in the area of the probe diagnostic of plasma. Simple problems are compared with theory and two dimensional effects are discused. Contribution of particle modeling to plasma research is showed on the problem of interaction of sheaths around cylidrical probes. We deal with question whether we are able to get some information about unevennesses at the surface of solid immersed in plasma by measuring probe characteristics in its surroundings. We also studied the influence of plasma electronegativity on the parameters of sheaths around cylidrical probes. Powered by TCPDF (www.tcpdf.org)
|
guest ::
