Effect of laser pulse shaping on ion acceleration via relativistic self induced transparency

We have studied the effect of the thick, low density plasma slab on the time evolution of the laser pulse profile. The dispersive nature of the plasma makes it possible to naturally chirp the laser pulse. The resultant chirped pulse is subjected to the dual layer composite target (primary+secondary), and apparently an efficient acceleration of the ions are observed from the secondary layer. For this work we have used a p-polarized, Gaussian laser pulse with intensity fwhm ≈ 10 fs and peak intensity ≈ 8.5⨯1020 W/cm2. The optimum density of the primary layer results in efficient electron heating and creating a strong longitudinal electrostatic field, which accelerates the ions from the thin, sub-critical (≈ 0.1nc) secondary layer. The effect of the pre-plasma parameters on the final energies of the ions from the secondary layer is investigated.