Single particle dynamics in ultra intense laser fields including radiation cooling

Under extreme acceleration, charged particles can radiate strongly and the corresponding radiation damping/cooling can become important. This occurs when the radiated energy in a typical oscillation period (e.g. cyclotron period or laser period) is comparable to mc$^{2}$. In particular, under the presence of ultra high static fields or high intensity lasers the motion of particles in the ultrarelativistic regime can be severely affected by radiation damping. Using a single particle dynamics code and the Osiris 2.0 framework, and including radiation cooling, we have examined and identified the different qualitative regimes for single electron interaction with counter- and co-propagating ultra-intense lasers fields. For conditions where the radiation cooling is important, qualitative differences arise as compared with the scenarios where radiation cooling is absent; this is identified not only in the particle phase space trajectories, but also on the net velocity imparted to the counter-propagating electrons, and the possibility of cooling particle beams.