Mirnov oscillation analysis in IR-T1 tokamak
- I.A.U., Tehran (Iran, Islamic Republic of). Plasma Physics Research Center
Tokamak discharges are usually rather turbulent with a large spectrum of electric and magnetic fluctuations. Mirnov oscillations are caused by rotating magnetic island inside the plasma column originated by resistive instabilities. Depending on the size of the plasma column, the frequency spectrum of Mirnov oscillation is in the range from a few to tens of kHz. The authors employ the technique to analyze signals measured in the IR-T1 tokamak without and with resonant helical field (RHF). The time-resolved analysis just described applies to the time series of the signal produced by each Mirnov pick-up coil. They see that the resonant helical field has almost no influence on the plasma current and loop voltage and there is a slight decrease of the floating potential at plasma edge. The characteristic frequency of poloidal propagation of the magnetohydrodynamic (MHD) fluctuations can be determined by using the correlation techniques described. For this calculation they have used the signals from the coils located on vacuum chamber with low magnetic field because they are better correlated than the one from the coils in the high field side. They have shown that time-resolved spectral analysis can be easily applied to analyze the (MHD) oscillations in tokamak.
- OSTI ID:
- 428043
- Report Number(s):
- CONF-960634--
- Country of Publication:
- United States
- Language:
- English
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