REVIEW ON CONFINEMENT MODES ANALYSIS USING FAST FOURIER TRANSFORM IN TOKAMAK PLASMA

FFT analysis is a satisfactory technique for detection plasma confinement modes in tokamaks. The confinement mode of tokamak plasma was analyzed using the Fast Fourier Transformation (FFT). For this purpose, we used the data of Mirnov coils that is one of the identifying tools in the IR-T1 tokamak, in the presence of external field (Biasing) as well as in its absence, and then compared it with each other. After the Fourier analysis of Mirnov coils data, the diagram of power spectrum density was depicted in different angles of Mirnov coils into two modes of ‘presence of external field’ as well as the ‘absence of external field’. The PSD interprets the manner of power distribution of a signal with frequency. In this article, the plasma modes numbers and the Safety factor of q were obtained by using the mode number of q=m/n (m is the mode number). The maximum MHD activity was obtained in 30-35 kHz frequency, using the density of energy spectrum. In addition, the number of different modes across 0-35 ms time was compared with each other in the presence of outer field as well as in its absence.