Electron acceleration mechanisms in cone targets - scaling up the energy of laser accelerated ions

In 2009, at the LANL Trident laser facility a new world record in laser accelerated proton energy has been set, exceeding 65 MeV, using hollow conical targets. We performed 2D collissional PIC simulations and identify two novel electron acceleration mechanisms that have not been considered before to enhance ion acceleration: the direct acceleration of electrons comoving with the driving laser along the the cone-wall inner surface (DASE) and the acceleration of electrons in surface plasma waves (PWA). We nd that they are responsible for a signicant increase in both electron number and energy in the case of a grazing laser incidence onto the inner cone wall surface compared to regular flat foils. We study the scaling of the electron and ion energies for various target and laser parameters.