High energy electron bunch generation by using a plasma separator

In this paper, we propose an electron acceleration by using an intense short pulse laser and a thin slab plasma separator. When an intense short pulse laser illuminates electrons in vacuum, the electrons are accelerated by the ponderomotive force at the front of laser pulse and the electrons accelerated loose their energies at the tail of laser pulse. This is one of serious problems in the ponderomotive electron acceleration. In order to suppress the energy loss, we propose an overdense plasma separator to extract the electrons before entering the deceleration region of laser pulse. In our electron acceleration mechanism, only the laser is reflected by the overdense plasma separator and the electrons pass through the plasma separator. Consequently, the electrons can obtain a net energy after the interaction with the laser pulse.