Optically guided laser wake-field acceleration*

The laser wake-field acceleration concept is studied using a general axisymmetric formulation based on relativistic fluid equations. This formalism is valid for arbitrary laser intensities and allows the laser–plasma interaction to be simulated over long propagation distances (many Rayleigh lengths). Several methods for optically guiding the laser pulse are examined, including relativistic guiding, preformed plasma density channels and tailored pulse profiles. Self-modulation of the laser, which occurs when the pulse length is long compared to the plasma wavelength and the power exceeds the critical power, is also examined. Simulations of three possible laser wake-field accelerator (LWFA) configurations are performed and discussed: (i) a channel-guided LWFA, (ii) a tailored-pulse LWFA, and (iii) a self-modulated LWFA.