Laser-driven Plasma Wakefield: Propagation Effects

In the frame of laser-driven wakefield acceleration, the main characteristics oflaser propagation and plasma wave excitation are described, with an emphasis onthe role of propagation distance for electron acceleration. To optimizeinteraction length and maximize energy gain, operation at low plasma density isthe most promising regime for achieving ultra-relativistic energies. Among thepossible methods of extending propagation length at low plasma density, laserguiding by grazing incidence reflection at the wall of dielectric capillarytubes has several assets. The properties of laser guiding and the measurement ofplasma waves over long distances are presented.