High-beam-quality electron acceleration in a vacuum by using two intersecting ultrashort, high-intensity laser pulses

The fact that electrons are accelerated by intense laser pulses in a vacuum is particularly apparent from recently published work, but up to now no high-beam-quality laser vacuum acceleration scheme has been presented. In this paper, numerical simulations demonstrate that free electrons can be accelerated axially (high beam quality) in a vacuum by using two intersecting ultrashort, high-intensity laser pulses. As the maximum intensities are on the laser axes, a hollow channel is formed between the two laser beams. The electrons will be expelled by the transverse ponderomotive force of each beam to the axis of the symmetry, and can be trapped inside the channel until they are accelerated to relativistic energies. This makes possible axial rather than radial acceleration.