• laser-matter interactions
• polarization effects
• radiation friction
• radiation pressure acceleration
• radiation reaction

At the extremely high laser intensities expected in next generation experiments, electrons can
become ultrarelativistic within a fraction of wave period experiencing superstrong accelerations therefore emitting large amounts of electromagnetic radiation. The Radiation Reaction (RR) force basically describes the back action on a single electron by its self-generated electromagnetic fields and it may significantly affect the dynamics at the extreme intensities expected in the foreseen laser-plasma interaction regimes.

In the present thesis, we present the results of our multi-dimensional Particle-In-Cell (PIC) simulations at ultra-high intensities showing the RR ability to reduce the electron heating and to increase both the electron and the ion bunching. Our approach is based on the Landau-Lifshitz equation of motion for electrons which is free from known problems of other approaches such as, e.g., runaway solutions. A detailed study of polarization effects at ultra-high intensities is also presented.