Coulomb explosion of nonuniformly charged nanospheres

Abstract

Coulomb explosion (CE) is an ion acceleration mechanism which involves the total expulsion of electrons from the target, and the repulsive forces between the remaining ions. In the event the laser does not provide the requisite input energy, and there are residual electrons, partial CE occurs.  This paper analyzes the partial CE dynamics of spherical nanoplasmas composed of ion mixtures. In particular, we created a simulation using a Python-Fortran code and examined the resulting ion energy spectra, and energy scaling. Our results show that a decrease in the electron temperature creates a more dominant screening effect that impedes ion motion, which results in bimodal energy distributions in some cases. Lastly, the energy scaling plot provided a clearer picture of the relationship between electron temperatures, target composition, and maximum proton energies.