EFDA-JET-CP(01)02/68
On the Radial Scale of Turbulent Transport in the JET Plasma Boundary Region
Dimensionless scaling investigations have been used to reveal the physical dependencies of plasma transport in fusion plasmas. The dimensionless parameter r* (gyro-radius normalized to the plasma minor radius) plays a mayor role in determining the transport processes (e. g. Bohm, gyro-Bohm or other non-Bohm type processes). In particular, if the radial scale is of the order of the gyro-radius, a gyro-Bohm type transport results, whereas the existence of radially elongated structures would imply Bohm type transport coefficients. However, the average radial correlation of broadband fluctuations is typically of the order of 1cm. These results emphasize the importance of studying the statistical properties of turbulent transport and fluctuations. In this paper we present experimental evidence of an empirical similarity in the statistical properties of turbulent transport and non-gaussian features in the radial coherence of ExB transport in the JET plasma boundary region, just inside the separatrix.
