Abstract
With persistent progress in ultra-intense laser pulses, Coulomb explosion (CE) of spherical nanoclusters can in principle produce high-quality-quasi-monoenergetic ions. Focusing on using CE framework, in this paper, we have proposed a target scheme to accelerate light/heavy ions’ beam. The scheme relies on encapsulating a hollow Gold nanocluster inside a hollow proton-Carbon (HC) nanosphere. The ability of this suggestion has been simulated by the two-dimensional particle-in-cell code (EPOCH). Simulation results exhibit that a hollow Gold cluster can positively increase the electrons’ extraction. This condition may improve the acceleration of low-divergence H+, C6+, and Au67+ ions. Our simulation shows that at the end of the interaction, for a Gold cluster with an optimal hollow radius of 91.3 nm, the cut-off energy of H+, C6+, and Au67+ are about 54.9 MeV/u, 51.5 MeV/u, and 54.9 MeV/u, respectively. In this case, an increase of about 52% for H+ and 61% for C6+ is obtained, contrast to bare HC hollow nanosphere (i.e., a hollow nanosphere with no cluster), while the relative divergence decreases to 1.38 and 1.86, respectively for H+ and C6+ ions. We have also compared our simulation results with another proposed target structure composed of a void area with an optimum diameter of 70.4 nm between the fully- Gold nanocluster and HC nanosphere. We have exhibited that the results are improved, contrast to bare nanosphere. However, the cut-off energy suppression and angular divergence increase are shown compared with encapsulated hollow Gold nanocluster structure.
Particle-in-cell simulations of high-energy electron production by intense laser pulses in underdense plasmas
