The effect of magnetic field modification on heavy ion movement in advanced stellarators and helical devices

Two new physics mechanisms that can be used to shield and exhaust the impurity ions in the toroidal magnetic traps with the rotational transform from the external current coils are considered here. One of them is connected with the stochastic magnetic fields, which can be the barrier for the penetration of impurity ions from the outside in the confinement volume. This way is appropriate in advanced stellarator systems such as the Wendelstein 7 X and the Helias Reactor. Another approach is a possibility to use the process of transition of particles with the blocked trajectories into the helical trapped particles. The particles that should be removed from the center of the confinement volume can go away along the transit trajectories. Such mechanism can be used in the helical device with the noticeable fraction of the transit particles, particularly the large helical device.