  An integrated simulation approach fully based upon particle-in-cell (PIC)
model is proposed, which involves both fast particle generation via laser
solid-density plasma interaction and transport and energy deposition of the
particles in extremely high density plasma. It is realized by introducing two
independent systems in a simulation, where the fast particle generation is
simulated by a full PIC system and the transport and energy deposition computed
by a second PIC system with a reduced field solver. Data of the fast particles
generated in the full PIC system are copied to the reduced PIC system in real
time as the fast particle source. Unlike a two-region approach, which takes a
single PIC system and two field solvers in two plasma density regions,
respectively, the present one need not match the field-solvers since the
reduced field solver and the full solver adopted respectively in the two
systems are independent. A simulation case is presented, which demonstrates
that this approach can be applied to integrated simulation of fast ignition
with real target densities.
