Dynamics of vortex flux entering the superconductor containing flux of
the opposite sign (antivortices) is considered. The interface point s
eparating flux-antiflux domains is described by the solution moving in
side the negative flux region. If vortices and antivortices penetrate
a superconductor from the opposite sides of the sample symmetrically,
the stationary flux-antiflux spatial distribution is described by the
universal scaling law. Heat released by the vortex-antivortex annihila
tion forms a spatial temperature wave running across the sample. When
velocity of the flux exceeds some critical value, it is predicted that
the overheating instability will grow.