An analytical optimization of plasma density profiles for downramp injection in laser wake-field acceleration

Abstract

We propose and detail a multi-step analytical procedure, based on an improved fully relativistic plane model for Laser Wake Field Acceleration, to tailor the initial density of a cold diluted plasma to the laser pulse profile, so as to control the spacetime localization and features of wave-breakings of the plasma wave and maximize the early stage acceleration of small bunches of electrons self-injected by the first wave-breaking at the density down-ramp. We find an excellent agreement with the results of 1D Particle In Cell simulations obtained with the same input data.