Proton acceleration in the interaction of an intense laser light with a cone plasma target and coated proton layer

To increase the acceleration rate for producing highly energetic protons, a scheme using a cone-shaped target with a coated proton layer is proposed and demonstrated by 2D particle-in-cell (PIC) simulation. The simulation results show that because the laser light and electrons are guided along the cone wall, the energy and density of hot electrons are enhanced in the cone target. Thus, the amplitude of the sheath field on the target's rear surface is enhanced, since it is proportional to the hot electrons' temperature and the logarithm of their density. Therefore, protons are accelerated strongly by this sheath field. (author)