  The propagation of filaments in the Scrape Off Layer (SOL) of tokamaks
largely determine the plasma profiles in the region. In a conduction limited
SOL, parallel temperature gradients are expected, such that the resistance to
parallel currents is greater at the target than further upstream. Since the
perpendicular motion of an isolated filament is largely determined by balance
of currents that flow through it, this may be expected to affect filament
transport. 3D simulations have thus been used to study the influence of
enhanced parallel resistivity on the dynamics of filaments. Filaments with the
smallest perpendicular length scales, which were inertially limited at low
resistivity (meaning that polarization rather than parallel currents determine
their radial velocities), were unaffected by resistivity. For larger filaments,
faster velocities were produced at higher resistivities, due to two mechanisms.
Firstly parallel currents were reduced and polarization currents were enhanced,
meaning that the inertial regime extended to larger filaments, and secondly a
potential difference formed along the parallel direction so that higher
potentials were produced in the region of the filament for the same amount of
current to flow into the sheath. These results indicate that broader SOL
profiles could be produced at higher resistivities.
