Presentation 1 : Oral
Alfven wave filamentation (PNST)
P.L. Sulem, T. Passot and D. Laveder
Formation of intense magnetic filaments by transverse collapse of
small-amplitude parallel Alfven waves is demonstrated using numerical
simulations of the Hall-MHD equations and envelope formalism,
both for plane waves and longitudinally homogeneous beams. For wave
packets, a minimal longitudinal extension is required for a blowup
associated with the formation of anisotropic magnetic structures.
Including kinetic effects is feasible in the limit of long
Alfven waves and is presently under way. When the wave amplitude is
increased, the filaments become helicoidal and a (transverse) "reduced
MHD" turbulence develops at large longitudinal scales.