Electron acceleration by means of short powerful laser pulses: a brief review of the modern state

Significant progress has been made in recent years using lasers for electron acceleration to high energies in plasmas. The main idea of such laser-plasma schemes is based on an opportunity to use the lasers for generation a large amplitude regular plasma wave with strong longitudinal electric field and relativistic phase velocity, which is capable of acceleration injected electrons. The great interest to these accelerators is due to their ability to sustain extremely large acceleration gradients (<100 GeV/m) essentially exceeding the acceleration gradients of conventional radio-frequency linear accelerators (>100 MeV/m). At the first stage, the main attention was attracted to plasma beat wave accelerator scheme (PBWA) where two-frequency laser radiation was used to create a plasma wave. With development of chirped pulse amplification (CPA) and powerful laser systems, the new methods for excitation of large amplitude relativistic plasma waves appear as the laser wake-field accelerator (LWFA) and self-modulated laser wake-field accelerator (SM-LWFA). This report is intended to give a brief overview of up to date results obtained for different schemes of laser-plasma based accelerators. The problems and plans of future investigations are also discussed.