Effect of preplasmas on high-energy ion generation by an intense laser pulse irradiated on overdense plasmas

High-energy ion generation from the interaction of an ultrashort intense laser pulse with an overdense plasma slab is studied with fully electromagnetic and relativistic particle-in-cell simulation. With a properly designed underdense preplasma, we observed that the forward ion acceleration from the front surface can be enhanced. The momentum distribution functions of the accelerated ions are investigated with respect to the laser pulse intensity and the preplasma profile.