Přispěvatelé: |
van Milligen, P, Carreras, B, Pedrosa, M, Balbín, R, Hidalgo, C, Newman, D, Sánchez, E, García-Cortés, I, Bleuel, J, Endler, M, Riccardi, C, Davies, S, Matthews, G, Martines, E, Antoni, V, Latten, A, Klinger, T, van Milligen, B |
Popis: |
Long-range correlations in turbulence, associated with self-similarity of the fluctuations, are a signature of transport by avalanches as occurs in Self-Organized Critical systems. We have investigated long-range correlations in plasma edge fluctuations in a variety of fusion devices, using the Rescaled-Range and similar techniques. We find that the degree of self-similarity in confining devices is high and similar between devices, and much different from non-confining devices where it is low. Likewise, we find that turbulent spectra show a high degree of similarity between devices. These findings strongly indicate the existence of universality in plasma edge (ohmic) turbulence, and demonstrate its non-Gaussian character. |