Er×B flow shear is simulated with a fully kinetic five-dimensionalneoclassical Monte Carlo simulation both for JET and ASDEX Upgrade. Here,Er is the radial electric field and B is the magnetic field. It is shownthat high enough shear for turbulence suppression can be driven at low (L)to high (H) transition conditions without taking into account anomalousprocesses in Er shear formation. For typical plasma parameters, at a certainedge temperature, shear is weaker in JET than in ASDEX Upgrade, thus requiringa higher edge temperature for L-H transition as observed also in experiments.However, although the simulation is carried out at experimentally observed L-Htransition temperatures of each device, shear is still weaker in JET, whichproposes that the critical shear in JET should be lower than in ASDEX Upgrade.The parametric dependence of the shear on temperature, density and magnetic fieldis investigated and the effects of density and temperature gradients, plasmacurrent and the direction of the ∇B drift on the shear are discussed.
Analysis of the E × B flow shearing rate in JET ITB discharges