Enhanced proton acceleration from near-critical density targets employing intense lasers with mixed polarization

Abstract

We demonstrate a scheme for enhanced proton acceleration from near-critical-density targets by splitting a laser pulse into a linearly and a circularly polarized laser pulse. The combination of two laser pulses generates a shock wave as well as hole boring effect at the front surface of the target. Protons at the front get combined acceleration from the two acceleration mechanisms. 2D-PIC simulation shows nearly two-fold enhancement in proton energy from this mechanism for a near-critical density target. The acceleration mechanism is also studied with different target density and thickness to ascertain the target parameters over which the acceleration process shows dominant behaviour.