Ion Acceleration by an Electrostatic Field in the InteractionBetween Femtosecond Laser Pulses and Solid Targets

We have studied the ion emission in the interaction between femtosecond laser pulses and solid targets by experiments and particle-in-cell (PIC) simulations. We found experimentally that almost all of the fast ions are confined within a cone symmetrically around the normal direction of targets. The PIC simulation results demonstrate that the fast ion beam can be accelerated by the laser-induced electrostatic field in front of solid targets.