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Numerical method of solar corona electron temperature measurement
Dospiva, Jindřich ; Žák, Libor (referee) ; Druckmüller, Miloslav (advisor)
This thesis is about the calculation of a spectral radiance for the K-corona, the continuius spectral part which arise from the Thomson scattering of a solar radiance of free electrons in the corona. Also the Doppler effect is described as it smooth down a solar spectrum (with many absorption lines) to a smoother spectrum of the K-corona. It’s also possible to determine the temperature of free electrons from spectral shape, from which proceeds the method of temperature measurement. NASA intends to use this method on the probe ONSET. Also, temperature definition and its significance are discussed.
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Experimentální studium centrální a okrajové oblasti prstence plazmatu na tokamaku Compass
Štefániková, Estera ; Tichý, Milan (advisor) ; Hron, Martin (referee)
High-resolution Thomson scattering system on the COMPASS tokamak provides electron temperature and density profiles in the central and edge plasma region. The spatial resolution in the edge plasma region is optimized for edge transport barrier studies. Formation of characteristic edge profiles (pedestals) is observed during high-confinement mode, i.e. the core electron temperature and density are raised up by the value of pedestal height. Both the electron and density pedestals are well-fitted by a modified hyperbolic tangent (mtanh) function, a five parameter model giving important parameters such as pedestal height and width, necessary for further analysis of the physics behind the transport barrier formation. A fitting technique of the full radial profiles of electron temperature, density and pressure during H-mode is also described. Using the fitting, electron temperature and density on top of pedestal are statistically processed to find a possible threshold for various H-mode regimes.
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Numerical method of solar corona electron temperature measurement
Dospiva, Jindřich ; Žák, Libor (referee) ; Druckmüller, Miloslav (advisor)
This thesis is about the calculation of a spectral radiance for the K-corona, the continuius spectral part which arise from the Thomson scattering of a solar radiance of free electrons in the corona. Also the Doppler effect is described as it smooth down a solar spectrum (with many absorption lines) to a smoother spectrum of the K-corona. It’s also possible to determine the temperature of free electrons from spectral shape, from which proceeds the method of temperature measurement. NASA intends to use this method on the probe ONSET. Also, temperature definition and its significance are discussed.
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Thomson Scattering Diagnostic on COMPASS Tokamak
Aftanas, Milan ; Stöckel, Jan (advisor) ; Mlynář, Jan (referee) ; Wild, Jan (referee)
Thorough study of plasma behaviour in magnetically confined fusion devices is of great importance in recent research. Diagnostics capable to reliably provide important parameters of the hot plasma are key tool in the effort to control fusion energy on Earth. Thomson Scattering diagnostic has a credit of being a complex design diagnostic with reliable measurement of electron temperature and density profiles. The main subjects of this thesis are design of the Thomson Scattering system for the COMPASS tokamak, analysis of output data errors and exploitation of the data to study plasma behaviour. Besides this work, the author has been involved in the design of Thomson Scattering systems for the ITER tokamak and this design is presented here as well. Powered by TCPDF (www.tcpdf.org)
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Experimentální studium centrální a okrajové oblasti prstence plazmatu na tokamaku Compass
Štefániková, Estera ; Tichý, Milan (advisor) ; Hron, Martin (referee)
High-resolution Thomson scattering system on the COMPASS tokamak provides electron temperature and density profiles in the central and edge plasma region. The spatial resolution in the edge plasma region is optimized for edge transport barrier studies. Formation of characteristic edge profiles (pedestals) is observed during high-confinement mode, i.e. the core electron temperature and density are raised up by the value of pedestal height. Both the electron and density pedestals are well-fitted by a modified hyperbolic tangent (mtanh) function, a five parameter model giving important parameters such as pedestal height and width, necessary for further analysis of the physics behind the transport barrier formation. A fitting technique of the full radial profiles of electron temperature, density and pressure during H-mode is also described. Using the fitting, electron temperature and density on top of pedestal are statistically processed to find a possible threshold for various H-mode regimes.
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Navrh filtru pro detekci Thomsonovym rozptylem na tokamaku COMPASS
Aftanas, Milan ; Scannell, R. ; Bílková, Petra ; Böhm, Petr ; Weinzettl, Vladimír ; Walsh, M.
Reinstalled tokamak COMPASS, originally from Culham Science Centre, is now operating at the Institute of Plasma Physics, Prague and many new optical diagnostics are being developed [Sestak et al, 2009]. For measurement of electron temperature and density profiles, high resolution incoherent Thomson scattering spectroscopy based on Nd:YAG laser and avalanche photodiodes is under development now. The paper outlines part of the design of this diagnostic - proper choice of spectral filters. The design of filters is shown and its evaluation taking into account different angle of scattered light is introduced. Error bars of the electron temperature, density and pressure are determined with respect to assumed electron temperature and density profiles and to required high spatial resolution at the pedestal region.
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Odhad zareni z plazmatu v systemu Thomsonova rozptylu projektovaneho pro tokamak COMPASS
Aftanas, Milan ; Böhm, Petr ; Weinzettl, Vladimír ; Stöckel, Jan
The COMPASS tokamak, originally from Culham laboratory, UKAEA, has been reinstalled at at Institute of Plasma Physics, Prague. Many innovations will be done and new diagnostics have to be constructed. Electron temperature Te and density ne as as key parameters of fusion plasma will be measured directly by the newly designed high spatial resolution incoherent Thomson scattering (TS) system. Several construction options of TS are considered. In this paper these options are discussed from a point of view of data analysis and estimation of background radiation.
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Využití lavinových fotodiod pro diagnostiku Thomsonova rozptylu na tokamacích
Aftanas, Milan ; Bělský, Petr ; Böhm, Petr ; Weinzettl, Vladimír ; Brotánková, Jana ; Barth, R. ; van der Meiden, H.
The COMPASS tokamak, originally from UKAEA, Culham laboratory, U.K., will be reinstalled at Institute of Plasma Physics, Prague. The scientific programme is focused mainly on the investigation of the edge plasma region with high temperature and density gradients called pedestal. Many innovations will be done and new diagnostics have to be constructed. One of the key diagnostics is an incoherent Thomson scattering for measurements of electron temperature Te and density ne with a high spatial resolution. In this paper a possibility of using a Nd:YAG laser in combination with a detection system based on Avalanche Photodiodes is discussed.
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Nový systém s vysokým rozlišením pro měření Thomsonova rozptylu na tokamaku COMPASS
Brotánková, Jana ; Bělský, Petr ; Weinzettl, Vladimír ; Böhm, Petr ; Barth, R. ; van der Meiden, H.
Thomson Scattering (TS) is a powerful technique capable to measure electron temperature and electron density. For TS on the COMPASS tokamak, several possible systems were considered and relevant parameters were calculated for both edge and core plasma studies. To attain the expected values of electron density and temperature, two possibilities were chosen to be the most suitable: (i) Nd-YAG laser at the second harmonic frequency with Littrow spectrometers with ICCD cameras (for both core and edge systems), and (ii) Nd-YAG laser at the first harmonic frequency with Littrow spectrometer with CMOS camera (for the core) and spectral filters with APDs (for the edge).
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Nová diagnostika pomocí Thomsonova rozptylu pro tokamak COMPASS
Aftanas, Milan ; Bělský, Petr ; Böhm, Petr ; Weinzettl, Vladimír ; Brotánková, Jana ; Barth, R. ; van der Meiden, H.
The COMPASS tokamak, originally from UKAEA, Culham laboratory, U.K., will be reinstalled at Institute of Plasma Physics, Prague. The scientific programme is focused mainly on the investigation of the edge plasma region with high temperature and density gradients called pedestal. Many innovations will be done and new diagnostics have to be constructed. One of the key diagnostics is an incoherent Thomson scattering for measurements of electron temperature Te and density ne with a high spatial resolution. Several construction options are considered. In this paper a possibility of using a Nd:YAG laser in combination with a detection system based on Avalanche Photodiodes is discussed.
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