Published online by Cambridge University Press: 03 July 2012
A double-slice-foil target is proposed for the generation of quasi-monoenergetic proton bunches by intense laser pulses. In this new target structure, two symmetrical solid slices are adjoined obliquely to the front side of a plane double-layer target. Two-dimensional particle-in-cell simulations show that a large number of hot electrons are pulled out from solid slices and accelerated forward by direct laser acceleration, which lead to significant enhancement of the sheath field and the produced proton beam energy as compared with the normal plane double-layer target and some other modified targets. It appears that well-collimated proton bunches with energy larger than 200 MeV can be produced at the focused laser intensity of about 1021W/cm2 with the proposed target design.