  We studied nucleus-nucleus collision in strong magnetic field based on a
transport model. It is found that neutrons and protons can be separated from a
nucleus by strong magnetic field and neutron-rich high density nuclear matter
and low density proton collectivity matter can be formed during nucleus-nucleus
collision. The electric field produced by proton collectivity can accelerate
proton and charged meson up to very high energies. Besides the studies of
isospin physics such as symmetry energy, these results may help us to
understand the acceleration mechanisms of high energy charged particles in the
cosmic rays
