Interplay between Gyrokinetic Turbulence, Flows, and Collisions: Perspectives on Transport and Poloidal Rotation

International audienceThe impact of ion-ion collisions on confinement is investigated with the full-f and global gyrokinetic GYSELA code through a series of nonlinear turbulence simulations for tokamak parameters. A twofold scan in the turbulence drive and in collisionality is performed, highlighting (i) a heat transport expressed in terms of critical quantities—threshold and exponent, (ii) a first evidence of turbulent generation of poloidal momentum, and (iii) the dominance of mean flow shear, mediated through the turbulent corrugation of the mean profiles, with regard to the oft-invoked zonal flow shear