  This paper investigates the physics of plasma separation in a two species
rotating collisional Ohkawa filter, when the source of rotation is an orbital
angular momentum carrying wave. The electric field is treated self-consistently
with ion and electron radial motion. The injection of angular momentum causes
radial currents leading to charge penetration and electric field build up. The
electric field varies until an equilibrium with the friction forces is reached.
Both collisions with neutrals and Coulomb collisions are considered. In the
case where the electric field is driven by the resonant wave, there is no
collisional breakdown of the Brillouin limit [Rax et al., Phys. Plasmas 22,
092101 (2015)]; on the contrary, the maximum achievable electric field
decreases when the collision frequency is increased. When two species are
present, one that undergoes the wave forcing while the second does not interact
with the wave, we find the following: the first species is confined, while the
second species can be expelled or confined depending on the charge to mass
ratio and the collisionalities. Assuming equal charge numbers, if the second
species is the heavy one, it is always expelled, which is a standard result.
When the second species is the light one, it can also be expelled in the common
case where neutral collisions dominate over Coulomb collisions, which
constitutes a new result.
