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

We demonstrate a scheme for enhanced proton acceleration from near-critical density targets by splitting a laser pulse into a linearly and circularly polarized one. The combination of two laser pulses generates a shock wave and hole-boring effect at the front surface of the target. Protons at the front get combined acceleration from the two acceleration mechanisms. Two-dimensional particle-in-cell (PIC) simulation shows a nearly twofold enhancement in proton energy from this mechanism for a near-critical density target. The acceleration mechanism is also studied with different target densities and thicknesses to ascertain the target parameters over which the acceleration process shows dominant behavior.