Plasma density around a tokamak magnetic surface with nonlinear flows in the low-vorticity limit for visco-resistive collisional plasmas

Plasma density is not conserved on a magnetic surface, if nonlinear flows are considered. The analysis here presented leads to a complicated equation for the plasma density considering nonlinear flows in the collisional regime, including viscosity and in the low-vorticity approximation. The idea of the present treatment follows the lines of previous works, where it was shown that the low-vorticity case can be handled in a much better way than the general one. This treatment is relevant in the H-mode, where the levels of turbulence are low outside the internal barriers. Numerical results for the density around a magnetic field have been obtained for whole body tokamak plasmas. Ellipticity and triangularity are also included in our treatment and the numerical calculations show a strong dependence on the plasma shape. Negative and positive triangularities are also considered.