Dynamics of isolated plasma filaments passing through the resonant magnetic perturbation (RMP) region at the tokamak edge are considered. Within the linear stability analysis, the criterion on the RMP amplitude that is required to significantly affect the filament trajectory and shape is deduced. It is demonstrated that for small-scale filaments, characteristic for the inter-edge localized modes (ELM) turbulent activity at the edge, even a single magnetic island can be sufficient to induce fluctuations of the electrostatic potential that would lead to the effective distortion of the filament motion. In the case of ELM filaments, the suppression of the filament propagation requires a chain of overlapping magnetic islands, leading to the formation of the stochastic magnetic field region. For the specific case of the RMP extending into the scrape-off-layer region, it is shown that the short-circuiting of ∇B currents to the plasma sheath results in the filament splitting into smaller-scale secondary plasma blobs. The analytical results are supplied with data from the BOUT++ simulations of filament dynamics.
A. A. Stepanenko (Sun,) studied this question.