A hybrid particle-in-cell/fluid method is introduced to simulate the transport of intense ion beams in the solid plasmas. A two-dimensional numerical program opic2d-hybrid has been developed and it is used to study the collective behavior of the intense proton beam transport into the polyethylene and solid aluminum targets. It is shown that intense magnetic field is self-generated by the transport of intense proton beam in solid targets. This magnetic field is of benefit to pinch the proton beam. Moreover, due to the production of substantial free-electrons by the target heating and ionization, the stopping power of solid target become weaken, thereby lengthening the proton beam range. On the contrary, the increase of target temperature will reduce the resistivity and thus inhibit the generation of magnetic field. Furthermore, the target ionization leads to much stronger ion-ion scattering effect, thus resulting in the diffusion of protons in transverse space. These effects compete with each other and determine the transport behavior of intense proton beam. At the last, the physical factors contributing to the generation of magnetic field are also analyzed. Some means to increase the strength of magnetic field have been proposed in order to realize the pinch transport of intense proton beams in solid targets.
