A "slingshot" laser-driven acceleration mechanism of plasma electrons

We briefly report on the recently proposed [G. Fiore, R. Fedele, U. de Angelis, Phys. Plasmas 21 (2014), 113105], [G. Fiore, S. De Nicola, arXiv:1509.04656] electron acceleration mechanism named "slingshot effect": under suitable conditions the impact of an ultra-short and ultra-intense laser pulse against the surface of a low-density plasma is expected to cause the expulsion of a bunch of superficial electrons with high energy in the direction opposite to that of the pulse propagation; this is due to the interplay of the huge ponderomotive force, huge longitudinal field arising from charge separation, and the finite size of the laser spot.