  A preliminary numerical experiment is conducted for laboratory experiments on
the generation of magnetized collisionless shocks with high-power lasers by
using one-dimensional particle-in-cell simulation. The present study deals with
the interaction between a moving Aluminum plasma and a Nitrogen plasma at rest.
In the numerical experiment, the Nitrogen plasma is unmagnetized or magnetized
by a weak external magnetic field. Since the previous study suggested the
generation of spontaneous magnetic field in the piston (Aluminum) plasma due to
the Biermann battery, the effect of the magnetic field is of interest. Sharp
jumps of electron density and magnetic field are observed around the interface
between the two plasmas as long as one of the two plasmas is magnetized, which
indicates the formation of tangential electron-magneto-hydro-dynamic
discontinuity. When the Aluminum plasma is magnetized, strong compression of
both density and magnetic field takes place in the pure Aluminum plasma during
the gyration of Nitrogen ions in the Aluminum plasma region. The formation of a
shock downstream is indicated from the shock jump condition. The result
suggests that the spontaneous magnetic field in the piston (Aluminum) plasma
plays an essential role in the formation of a perpendicular collisionless
shock.
