Interplay between edge magnetic topology, pressure profile and blobs in the edge of RFX-mod

The observation of the periodic pressure profile time oscillations in the edge region (0.93 < r/a < 1) of a RFX-mod device allows one to investigate the role of pressure as a turbulence regulation mechanism. The proportionality between the radial correlation length of edge fluctuations and the radial characteristic pressure length L-p suggests a sort of regulation of the turbulent spatial scale, where L-p sets the radial dimension of the blobs. Moreover, the spatial scale regulation is confirmed by observing a linear scaling between the energy injection scale and the toroidal dimension of the edge coherent structures. On the other hand, the link between Delta P-e and turbulence level does not hold locally: the edge fluctuation level is higher in the toroidal region of lower edge pressure gradient. Hence if coherent structures are generated locally in the region of strongest Delta P-e, they flow and accumulate where Delta P-e is lower.