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Paper   IPM / Astronomy / 12441
School of Astronomy
  Title:   Markov Properties of Electrical Discharge Current Fluctuations in Plasma
1.  S. Kimiagar
2.  M. Sadegh . Movahed
3.  S. Khorram
4.  M. Reza . Rahimi Tabar
  Status:   Published
  Journal: J. Stat. Phys.
  No.:  0710.5270
  Vol.:  143
  Year:  2011
  Pages:   148-167
  Supported by:  IPM
Using the Markovian method, we study the stochastic nature of electrical discharge current #64258;uctuations in the Helium plasma. Sinusoidal trends are extracted from the data set by the Fourier-Detrended Fluctuation analysis and consequently cleaned data is retrieved. We determine the Markov time scale of the detrended data set by using likelihood analysis. We also estimate the Kramers-Moyal’s coef #64257;cients of the discharge current #64258;uctuations and derive the corresponding Fokker-Planck equation. In addition, the obtained Langevin equation enables us to reconstruct discharge time series with similar statistical properties compared with the observed in the experiment. We also provide an exact decomposition of temporal correlation function by using Kramers-Moyal’s coef #64257;cients. We show that for the stationary time series, the two point temporal correlation function has an exponential decaying behavior with a characteristic correlation time scale. Our results con #64257;rm that, there is no de #64257;nite relation between correlation and Markov time scales. How ever both of them behave as monotonic increasing function of discharge current intensity. Finally to complete our analysis, the multifractal behavior of reconstructed time series using its Keramers-Moyal’s coef #64257;cients and original data set are investigated. Extended self similarity analysis demonstrates that #64258;uctuations in our experimental setup deviates from Kolmogorov (K41) theory for fully developed turbulence regime.

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