Ambipolar stochastic particle diffusion and plasma rotation

The motion of electrons and ions in stochastic magnetic fields is considered. The analysis starts from a Hamiltonian formulation of the drift motion including electric fields. For an efficient statistical evaluation of the resulting particle transport, a symplectic mapping technique is applied. Compared to previous considerations, the ion and electron test particle motion are investigated simultaneously, allowing calculations of the ambipolar electric field and its influence on stochastic transport. The predictions based on the relativistic drift model are applied to the magnetic perturbations in the TEXTOR-DED [A. Wingen, Nucl. Fusion 46, 941 (2006)]. The influence of the magnetic coil arrangement on the poloidal plasma rotation, caused by the generated radial electric field, is discussed.