The Effect of laser pulse incidence angle on the proton acceleration from a double-layer target

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

We investigate theoretically and with three dimensional particle-in-cell simulations high quality laser proton acceleration for the oblique incidence of a high intensity 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 greater 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.