Self-resonant wakefield excitation by intense laser pulse in plasmas

Summary form only given. It has been demonstrated by theoretical analysis and numerical calculations that in an underdense plasma the process of three-dimensional evolution of the short and strong laser pulse (with duration equal to several plasma periods) leads to compression and self-modulation of the pulse, so that, during a fairly long period of time, beats of pulse amplitude generate resonantly a strong and stable plasma wake field. The intensity of the wake field is so high that it can provide a new promising outlook for the plasma-based accelerator concept. Numerical simulations demonstrate that the self-focusing and resonant-modulation instability considered here are essentially three-dimensional processes. Laser field evolution in each transverse cross section of the pulse is synchronized by the regular structure of the plasma wave that is excited by the pulse. The effect of resonant modulation has a threshold; for pulses with an intensity below the threshold, the refraction dominates and no modulation appears.