Laser acceleration of charged particles in inhomogeneous plasmas II: Particle injection into the acceleration phase due to nonlinear wake wave-breaking

Results from analytical studies and computer simulations of the nonlinear e volution of wake waves in inhomogeneous plasmas are presented. It is shown that the wake wave-breaking that appears due to the inhomogeneity of the La ngmuir frequency can be used to inject electrons into the acceleration phas e of the wave. In the wake wave excited behind a finite-width laser pulse, the wave-breaking mechanism involves the increase in the curvature of the w ake front with the distance from the pulse, followed by the self-intersecti on of the electron trajectories.