Plasma turbulence, nonlinear structures and cascades as seen in spacecraft and fusion-science data

We study nonlinear coupling of waves and the cascades near the outer Magnetospheric boundaries and compare the coupling with that in fusion devices. In [Budaev et al, JPP 81 (2015) 395810602] we demonstrated some universalities of turbulence in both space and fusion turbulent plasma. We conclude that the magnetopause resembles edge plasma in fusion devices. In both media, nonlinear bursts/structures lead to the intermittent anomalous transport. We discovered in space data (CLUSTER, INTERBALL-1, DOUBLE STAR, SPECTR-R, GEOTAIL) very weak but effective nonlinear bursts that govern, at first, the discrete 3-wave cascades at 0.3-10 mHz in the energetically dominant dynamic pressure. The 3-wave cascades (being smeared by the turbulent background plasma) transfer into the developed turbulence at the higher frequencies. We have detected those weak waves in the sunward Poynting flux component. We discuss the nature of these quasi-discrete waves, whether they are fast magnetosonic or fast Alfven nonlinear waves. Comparative analysis of space data with the fusion database is now a foundation for the program on plasma turbulence, nonlinear structures and cascades being studied in new plasma device PLM (plasma linear multi-cusps) recently constructed at NRU Moscow Power Engineering Institute