Laser wakefield acceleration of short electron bunches

The theory of electron acceleration in a plasma wake wave is developed, and the dependence of the main characteristics of accelerated electron bunches on the wakefield parameters is investigated. It is shown that using a preb unching stage, under proper conditions, the final electron density of a com pressed and accelerated bunch can exceed the initial electron beam density by orders of magnitude and that longitudinal bunch compression provides qua si-monoenergetic acceleration to high energies. It is demonstrated that, fo r an initial electron beam radius smaller than the optimal one for efficien t beam trapping, the energy spread of the compressed and accelerated electr on bunch and its length can be evaluated by using the simple analytical pre dictions of a one-dimensional (I-D) theory, The obtained analytical results are confirmed by three-dimensional (3-D) numerical modeling.