Laser acceleration of light ions from high-intensity laser-target interactions

A systematic theoretical study of laser-irradiated targets made of material with increasing atomic number has been performed. The formation of energetic light ions resulting from the interaction of an intense ultrashort pulse laser with thin planar targets is investigated theoretically with a two-dimensional relativistic electromagnetic particle-in-cell model. A common parameter, the areal electron density of the foil, can be used to describe qualitatively targets made of different material. By varying either the laser intensity or the target thickness we observe a gradual transition of various ion acceleration mechanisms from one into another. Light ions, such as H⁺, Li³⁺, C⁶⁺, and Al¹³⁺, can be accelerated to GeV energies with existing laser systems at a laser fluence of 10–20 J/μm².