On spin of plasma blob in edge and scrape-off layer regions of a tokamak.

Rotation/spin of plasma blob in the edge and SOL regions in the presence of interchange plasma turbulence with a finite ion temperature gradient ( $ \nabla _\perp T_i $ ∇ ⊥ T i ) has been presented. $ \nabla _\perp T_i $ ∇ ⊥ T i destabilizes plasma, but damps the eddies related to the plasma blob by enhanced viscosity, therefore, rotation is important for plasma dynamics as the rotation further stabilizes the blobs. The turbulence has been simulated numerically and results show monopolar vorticity is responsible for blob rotation, but the physics is different in the edge and SOL regions. A radial profile of vorticity, and angular speed of a typical plasma blob have been presented. The role of $ \nabla _\perp T_i $ ∇ ⊥ T i has been identified. [ABSTRACT FROM AUTHOR]