Dynamics of laser-plasma expansion across strong magnetic field

Explosive plasma expansion in an external magnetic field occurs in a variety of space and astrophysical events that include supernova explosions in the interstellar magnetic field and the interaction of solar coronal mass ejections with planetary magnetospheres. Effects of the interaction of plasma winds with magnetic obstacles were investigated in the laboratory using a laser produced plasma plume and an external magnetic field created by a current driven through a metal rod by a pulsed power generator. Instabilities develop at the plasma-field boundary. In the frontal direction, along the normal to the target, flute-like instabilities grow and eventually lead to plasma penetration across the magnetic field with constant velocity. Along the lateral boundary, the plasma deceleration by the transverse magnetic field initiated a Kelvin-Helmholtz instability.