Abstract

Because electrostatic fields in a plasma wave (E ≥ 100 GV/m) can exceed by three orders of magnitude those in conventional RF linacs, plasma based accelerators can potentially offer a compact method for accelerating high energy electrons. Of the several methods for driving large amplitude plasma waves, the laser wakefield accelerator (LWFA) and its variant, the self-modulated LWFA, have recently received considerable attention because of the reduction in size of the terawatt class laser systems needed to drive the wakefield [1]. In this paper, we demonstrate all optical techniques based on frequency domain interferometry [2] and forward, collective Thomson scattering [3] for temporal characterization of the plasma wakefield. The ability to measure the plasma wake temporal structure is of fundamental importance for a number of issues, including: wakefield generation by optimized pulse trains, the design of particle injectors synchronized to the wakefield on a femtosecond time scale, and the growth dynamics of plasma wave instabilities.

© 1997 Optical Society of America