Spatial, temporal and spectral structure of the turbulence–flow interaction at the L–H transition

The physical mechanisms behind the L-H transition have been experimentally studied in the TJ-II plasmas. The spatial, temporal and spectral structure of the interaction between turbulence and flows has been studied close to the L–H transition threshold conditions. The temporal dynamics of the turbulence–flow interaction displays a predator–prey relationship and both, radial outward and inward propagation velocities of the turbulence–flow front have been measured. Moreover, the turbulence scales involved in the energy transfer of the predator–prey process have been identified. (paper)