Experimental Evidence of Long-Range Correlations and Self-Similarity in Plasma Fluctuations

To better understand long time transport dynamics, techniques to investigate long-range dependences in plasma fluctuations have been applied to data from several confinement devices including tokamaks, stellarators, and reversed field pinch. The results reveal the self-similar character of the edge plasma fluctuations. This implies that the tail of the autocorrelation function decays as a power law and suggests that there is a superdiffusive component of the anomalous transport. Rescaled fluctuation and turbulent flux spectra from different devices also show a strong similarity. For a range of parameters corresponding to the tokamak ohmic regime and equivalent power for other devices, the spectral decay index may show a universal character.

[1]  David E. Newman,et al.  The dynamics of sandpiles with a sheared flow , 1996 .

[2]  L. Giannone,et al.  Measurements and modelling of electrostatic fluctuations in the scrape-off layer of ASDEX , 1995 .

[3]  Bruce J. West,et al.  Fractal physiology , 1994, IEEE Engineering in Medicine and Biology Magazine.

[4]  D. Percival,et al.  Evaluating scaled windowed variance methods for estimating the Hurst coefficient of time series. , 1997, Physica A.

[5]  Sylvie Oliffson Kamphorst,et al.  On the fractal dimension of self-affine profiles , 1994 .

[6]  On the dynamics of turbulent transport near marginal stability , 1995 .

[7]  R. J. Fonck,et al.  Density fluctuation measurements via beam emission spectroscopy (invited) , 1992 .

[8]  Long-range time dependence in the cross-correlation function , 1999 .

[9]  D. Desideri,et al.  ELECTROSTATIC TURBULENCE AND TRANSPORT IN THE VELOCITY SHEAR LAYER OF A REVERSED FIELD PINCH PLASMA , 1998 .

[10]  B. Mandelbrot.  Self-Affine Fractals and Fractal Dimension , 1985 .

[11]  Tang,et al.  Self-Organized Criticality: An Explanation of 1/f Noise , 2011 .

[12]  P. Diamond,et al.  The dynamics of marginality and self-organized criticality as a paradigm for turbulent transport , 1996 .

[13]  Benjamin A. Carreras,et al.  Long-range time correlations in plasma edge turbulence , 1998 .

[14]  Paul W. Terry,et al.  Influence of sheared poloidal rotation on edge turbulence , 1990 .

[15]  J. R. Wallis,et al.  Robustness of the rescaled range R/S in the measurement of noncyclic long run statistical dependence , 1969 .

[16]  Hwa,et al.  Avalanches, hydrodynamics, and discharge events in models of sandpiles. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[17]  A. Navarro,et al.  Electrostatic and magnetic fluctuations in the proximity of the velocity shear layer in the TJ‐I tokamak , 1992 .

[18]  Wu,et al.  Scaling and universality in avalanches. , 1989, Physical review. A, General physics.

[19]  David E. Newman,et al.  Self-similarity of the plasma edge fluctuations , 1998 .

[20]  Jeffrey H. Harris,et al.  Plasma fluctuations near the shear layer in the ATF torsatron , 1991 .

[21]  Stevens,et al.  Self-similar transport in incomplete chaos. , 1993, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[22]  K. Tritz,et al.  The beam emission spectroscopy diagnostic on the DIII-D tokamak , 1999 .

[23]  J. R. Wallis,et al.  Noah, Joseph, and Operational Hydrology , 1968 .

[24]  David E. Newman,et al.  Empirical Similarity of Frequency Spectra of the Edge-Plasma Fluctuations in Toroidal Magnetic-Confinement Systems , 1999 .