Study of the neoclassical radial electric field of the TJ-II flexible   heliac
  Calculations of the monoenergetic radial diffusion coefficients are presented for several configurations of the TJ-II stellarator usually explored in operation. The neoclassical radial fluxes and the ambipolar electric field for the standard configuration are then studied for three different collisionality regimes, obtaining precise results in all cases. 
J. L. Velasco, F. Castejon
physics.plasm-ph