Enhanced laser-radiation-pressure-driven proton acceleration by moving focusing electric-fields in a foil-in-cone target

摘要

A foil-in-cone target is proposed to enhance stable laser-radiation-pressure-driven proton acceleration by avoiding the beam degradation in whole stage of acceleration. Two and three-dimensional particle-in-cell simulations demonstrate that the guiding cone can substantially improve the spectral and spatial properties of the ion beam and lead to better preservation of the beam quality. This can be attributed to the focusing effect of the radial sheath electric fields formed on the inner walls of the cone, which co-move with the accelerated foil and effectively suppress the undesirable transverse explosion of the foil. It is shown that, by using a transversely Gaussian laser pulse with intensity of similar to 2.74 x 10(22)W/cm(2), a quasi-monoenergetic proton beam with a peak energy of similar to 1.5 GeV/u, density similar to 10n(c), and transverse size similar to 1 lambda(0) can be obtained. (C) 2015 AIP Publishing LLC.