Hot electron emission limited by self-excited fields from targets irradiated by ultra-intense laser pulses

Abstract

A large number of hot electrons exceeding the Alfvén current can be produced when an ultra-intense laser pulse irradiates a solid target. Self-excited electrostatic and magnetic fields at the target rear could influence the hot electron transport. To investigate the influence, we measure the hot electrons when a pre-plasma is created on the target rear surface and verify an increase of the electron number by a factor of 2 comparing to the no rear plasma case. The increase may be caused because of changes in the electrostatic potential formation process. The retardation of the potential formation is shown using a particle-in-cell simulation. The electron number escaping within the retardation time duration is consistent with our estimation taking the Alfvén current into account.