Loizu, J.Morales, J. A.Halpern, F. D.Ricci, P.Paruta, P.2018-01-092018-01-092018-01-09201710.1017/S0022377817000927https://infoscience.epfl.ch/handle/20.500.14299/143668WOS:000417674400011We investigate the question of how plasma currents circulate and close in the scrape-off-layer (SOL) of convection-limited tokamak plasmas. A simplified two-fluid model describes how currents must evacuate charge at the sheaths due to cross-field currents that are not divergence-free. These include turbulence-driven polarization currents and poloidally asymmetric equilibrium diamagnetic currents. The theory provides an estimate for the radial profile of the floating potential, which reveals a dipolar structure like the one observed experimentally. Simulations with a fluid turbulence code provide evidence for the predicted behaviour of currents and floating potential.CRPP_EDGEtext::journal::journal article::research article