Proton acceleration by oblique laser pulse incidence on a double-layer target

Morita, Toshimasa; Esirkepov, T. Z.; Bulanov, S. V.; Koga, J. K.; Yamagiwa, Mitsuru

We investigate high quality laser proton acceleration with three dimensional particle-in-cell simulations for oblique incidence of the laser pulse on a double-layer target. The double-layer target is composed of a high-Z ion layer coated by a thin and narrow hydrogen patch. The highest proton energy gain is achieved at a certain incidence angle at which the fast proton maximum energy is much grater than the case of normal incidence. The fast protons form a tilted bunch which propagates at some angle with the respect to the normal of the target surface, as determined by the proton energy and the incidence angle.