High-energy collimated electron acceleration from ultra-intense laser interaction with tube targets

Two-dimensional PIC (particle-in-cell) simulation is used to investigate the interaction between ultra-intense short-pulse lasers with tube targets. When an ultra-intense super-Gaussian laser pulse propagates at a grazing incidence angle into the tube target, GeV-class electron acceleration is observed on the inner surface. Fast electrons are confined along the surface by quasistatic electric and magnetic fields, resulting in a small divergence angle of the generated electron beam. These surface fast electrons can be accelerated for a long distance along the tube; as a result, the energy conversion efficiency is very high. The influence of the laser intensity and the transverse profile on the surface electron acceleration process is also discussed in the article.