  The stabilization of tearing modes with rf waves is subject to a nonlinear
effect, termed rf current condensation, that has the potential to greatly
enhance and localize current driven within magnetic islands. Here we extend
previous investigations of this effect with a two fluid model that captures the
balance of diffusive and thermal equilibration processes within the island. We
show that the effective power, and resulting strength of the condensation
effect, can be greatly enhanced by avoiding collisional heat loss to the ions.
The relative impact of collisions on the overall power balance within the
island depends on the ratio of the characteristic diffusion time scale and the
electron-ion equilibration time, rather than the latter alone. Although
relative heat loss to ions increases with island size, the heating efficiency
does as well. In particular, we show that the latter safely dominates for large
deposition profiles, as is typically the case for LHCD. This supports the
possibility of passive stabilization of NTMs, without the precise aiming of the
rf waves required for ECCD stabilization.

Plasma Physics