The effect of emissive biased limiter on the magnetohydrodynamic modes in the IR-T1 tokamak
- Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, P. O. Box 14665-678, Tehran (Iran, Islamic Republic of)
A moveable emissive biased limiter (EBL) for the investigation of spatial and temporal structure of MHD modes in IR-T1 tokamak, based on mirnov oscillations, was designed and constructed. The biasing has been considered to improve the global confinement by setting up an electric field at the plasma edge. Radial electric field (E{sub r}) modifies edge plasma turbulence, plasma rotation, and transport. Mirnov oscillations using singular value decomposition (SVD) and wavelet techniques were analyzed. SVD algorithm has been employed to analyze the frequency and wavenumber harmonics of the MHD fluctuations. The time-resolved frequency component analysis has been performed using wavelets. The EBL was applied to plasma at 10 ms with negative polarity. The results show that after applying EBL, the m = 2 mode is grown, m = 3 mode is suppressed, and H{sub {alpha}} radiation is decreased. Furthermore, results of the wavelet analysis of mirnov coil in the time range of 8-12 ms indicate that 1.5 ms after applying EBL, the MHD frequency is reduced from 45 kHz to 25 kHz.
- OSTI ID:
- 22107682
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 3 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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