Student: Kripner Lukáš
Vedoucí: Prof. RNDr. Zdeněk Němeček, DrSc.
Konzultant: Mgr. Vladimir Weinzettl, Ph.D., ÚFP AV CR, v.v.i.
Stav práce: obhájená
Abstrakt:
The COMPASS tokamak is the smallest divertor device with clear H-mode and ITER-relevant plasma geometry (1:10 to the ITER plasma size, R=0.56 m, a=0.23 x 0.38 m, Ip=200-400 kA, BT=1.2-2.1 T and pulse length up to 1 s).
MHD instabilities developing in many discharges of COMPASS strongly limit a plasma performance and can also cause an undesirable disruption. Different plasma diagnostics (magnetic coils, fast radiation detectors, probes) provide signals suitable for description of this plasma activity. Although, its general description has been already established many years ago, a theory-based physical image still does not correspond to observed data precisely.
The aim of the bachelor work is to review diagnostic tools available on the COMPASS tokamak, which can be used for tracking MHD activity. Consequently, an analysis of available data from selected discharges of the COMPASS tokamak with strong MHD activity, namely sawteeth and tearing modes, using fast Fourier transform, correlation and singular value decomposition methods should be performed. There, tracking of typical behaviour and plasma conditions for MHD activity development should be done.
Zásady pro vypracování:
1. Rešerše literatury týkající se MHD aktivity tokamkového plazmatu, a to zejména typu sawteeth a tearing modes.
2. Spolupráce na úpravě rutin (software) pro analýzu dat (FFT, SVD, korelační analýza).
3. Analýza dat z vybraných výstřelů tokamaku COMPASS, kde se objevuje silná MHD aktivita.
4. Shrnutí dosažených výsledků, zejména uvedení typických podmínek výskytu MHD aktivity ve výstřelech tokamaku COMPASS.
5. Vypracování písemné zprávy.
Studijní literatura:
1. J. Wesson: Tokamaks, 3rd edition, Clarendon Press, Oxford, 2004.
2. I. H. Hutchinson: Principles of Plasma Diagnostics, Cambridge University Press, 2nd edition, 2002.
3. V. Weinzettl, et al.: Overview of the COMPASS diagnostics, Fusion Eng. Des. 86 (2011) 1227-1231.
4. M. Maraschek: Control of neoclassical tearing modes, Nucl. Fusion 52 (2012) 074007.
5. I. T. Chapman: Controlling sawtooth oscillations in tokamak plasmas, Plasma Phys. Contr. F. 53 (2011) 013001.