Turbulence and flows in the plasma boundary of snowflake magnetic configurations

摘要

Results of 3D, flux-driven, global, two-fluid turbulence simulations are presented for the first time in snowflake (SF) configurations, including the ideal SF, SF plus and SF minus configurations. The analysis is focused on the distribution of the heat flux along the four divertor legs in the sheath-limited regime and on the mechanisms that activate the four strike points. A steady E × B equilibrium flow in the X-point region is found to play an important role for the activation of the four strike points, especially in the ideal SF case. Turbulent transport, observed in the region between the two separatrices for the SF minus configuration when the secondary X-point is on the low-field side, contributes to the redistribution of heat flux among the strike points.