The origin of the long time correlations of the density fluctuations in the scrape-off layer of the Tore Supra tokamak
It is shown that intermittent density bursts observed in the scrape-off layer of Tore Supra fJ. Jacquinot, Nucl. Fusion 43, 1583 s2003dg are detected in packs on the probe. In such a pack, typically two to three bursts are separated by time intervals smaller than the mean separation time. The long tails above 50 ms observed on the autocorrelation function of the density fluctuations are found to be the temporal correlation between the individual bursts within their pack. Packs of density bursts can be detected in two limiting states of the turbulence: when the coupling between density and potential is strong and large density bursts split during their radial propagation or at the opposite when the coupling is weak so that different density bursts can propagate radially along the potential valleys. The lack of spatial resolution of the diagnostic does not allow to discriminate between the two mechanisms.
Bibliographic Reference: An article published in: Physics of Plasmas 12, 050702 s2005d
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: DOI: 10.1063/1.1894399g
Record Number: 200518119 / Last updated on: 2005-05-20
Original language: en
Available languages: en