Expanding of a plasma cloud of complicated form into rarefied plasma in the magnetic field

The collisionless interaction of expanding plasma cloud with magnetized background plasma in a axial magnetic field is studied. In a initial cylindrical form of expanding plasma cloud some pertubations are included and the developement in a time of these pertubations is investigated. The expansion velocity of plasma cloud is much more than the Alfven velocity in a background plasma. The hybrid model of process, in which ions are treated as particles and described by Vlasov–Maxwell equations, elections are treated as fluid and described by MHD equations is used. This system of equations is solved by computer simulation using particles method.
It was shown that the axial asymmetry of expanding cloud leads to the formation of localized in a space plasmoids in the cloud and background plasma, which are moving in a radial and azimuthal directions.