Wave generation by exploding plasma clouds

Summary form only given. The processes of collisionless interaction of plasma flows play a main part in dynamics of such non-stationary astrophysical phenomena as Supernova bursts and solar flares, active experiments in space. As a result of such interaction in the surrounding background the waves and shock fronts are generated. For the example of the problem on the collisionless expansion of a spherical plasma cloud in a magnetized plasma the energy change mechanism of the cloud-background interaction and structure of disturbances has been investigated. We use a 2D electromagnetic hybrid code (particle ions, fluid electrons). The method of solution is based on the application of the PIG-method and finite-difference splitting schemes. The following problem has been under consideration. At the initial moment of time in the centre of the cylindrical chamber with the uniform magnetic field filled by the background plasma there is a spherical cloud of dense plasma. The ion velocity of the cloud is distributed linearly on the radius and is directed from its centre. On the scales of the gas-dynamic radius of deceleration the asymmetric interaction of the expanding cloud with the background was seen. The flow perpendicular to the magnetic field was decelerated most intensively, the displacement of the field and the formation of a magnetic cavity took place.