Computational Physics of Photon Science

We study laser-matter interactions numerically by using massively parallel computers. The ion acceleration from a double layer target driven by a laser pulse with intensities I = 10-10 W/cm × (μm/λ) is investigated via multi-parametric particle-in-cell (PIC) simulations. For targets over a wide range of thicknesses l and densities ne, at a given intensity, the highest ion energy gain occurs for a certain electron areal target density σ = ne l, which is proportional to the square root of the intensity. It is also found that proton energies in the range of 200 MeV required for deep cancer therapy may possibly be achieved with high power lasers close to petawatt levels. Also reported are simulations of laser wake field acceleration of electrons and photons and laser and neutral gas interaction. Furthermore a first-principle calculation is described for the electron excitation of transparent material under an intense laser field showing that breakdown of the dielectric occurs under the intense laser field and that diamond behaves like a metal.