Laser driven electron acceleration

Issues pertaining to laser acceleration in vacuum, neutral gases and plasmas are discussed. For acceleration in vacuum the limitations due to electron slippage, laser diffraction, material damage and electron aperture effects are discussed. To achieve multi GeV electron energies in the laser wakefield accelerator (LWFA) it is necessary to propagate an intense laser pulse long distances in a plasma without disruption. It is shown that electron energies of /spl sim/GeV in a channel guided LWFA can be achieved by using short pulses where the forward Raman and modulation nonlinearities tend to cancel. Further energy gain can be achieved by tapering the plasma density to reduce electron dephasing.