Radiation friction modeling in superintense laser-plasma interactions

Radiation Friction or Reaction (RR) effects are important for highly relativistic electrons in superintense electromagnetic fields and are thus expected to play a crucial role in next-term experiments. It is therefore important to include RR in particle-in-cell (PIC) simulations of laser-plasma by an appropriate modeling, keeping the essential RR effects into account while retaining at the same time the capability to perform large-scale simulations. We describe a suitable approach, based on the Landau-Lifshitz equation, which allows the insertion of RR in PIC codes in a modular way and with a very reduced computational cost. Properties of the kinetic equation with RR which is effectively solved by the PIC method are also discussed. We then present the results of multi-dimensional PIC simulations, mainly on radiation pressure acceleration of thin foil targets, addressing the importance of RR effects and showing the strong role played by the laser pulse polarization.