Figure 1

This schematic diagram compares the charged particle dynamics in a focused light wave in the absence/presence of radiation reaction (RR) effects. The variation of laser intensity (hence laser electric field)along the direction of propagation (z-axis) due to focusing is shown by a colour bar. (a) and (b)represent particle trajectories with initial conditions which respectively lead to reflection and transmission through the focal point in the absence of radiation reaction forces (the green wavy lines in (a) and (b)). It is shown that inclusion of radiation reaction forces results in transmission through the focal point in both cases, irrespective of the choice of initial conditions, provided radiation reaction force dominates over the Lorentz force. On transmission, the increase in energy of the particle is also shown by change in colour.