Neoclassical nature of the radial electric field at the low-to-high confinement transition

The radial electric field Er at the tokamak plasma edge is simulated both with a two-dimensional (2D) fluid code solving the most complete system of transport equations and with five-dimensional (three-dimensional in configuration space and 2D in velocity space) Monte Carlo particle following code. At low to high confinement transition conditions, the Er×B shearing rate is found to be high enough for turbulence suppression even though the field is essentially neoclassical. Here, B is the magnetic field. No bifurcation of Er is found