Maximum Entropy Spectral Analysis of Time-Series Data from Combustion MHD Plasma

The maximum entropy method (MEM) was applied to the time-series intensity data of the total light radiation from a combustion MHD plasma, and power spectral densities with many characteristic peaks were obtained in the range of a few kHz to ca. 30 kHz. Minimization of FPE , AIC , and CAT was employed to determine the optimum prediction-error filter order required for the MEM spectral analysis. Using the plasma flow velocity of 250 m/s obtained from cross-correlation function analysis, the frequency spectrum of the temperature was transformed to the wave-number-dependent power spectral density, in which a k -5/3 -dependence was found in the k -range corresponding to the inertial subrange.