Radiation reaction in spatially modulated fields accelerators

It is possible to accelerate efficiently a charged particle toward the speed of light through a spatially modulated electrostatic field and through the superposition of a spatially modulated magnetic field and a laser. In both cases, the acceleration process requires an adequate initial velocity of the particle and depends on the amplitude of the fields, the length scale of the modulation and the wavenumbers, and frequencies of the fields. The physics behind these accelerators involves a resonance between the particle's velocity and the field's phase velocity. The promising results, however, may be affected when the radiation reaction effect is included in the calculations. Understanding the role of the radiation reaction over these schemes is the aim of the present work. As we are going to show, in a counter-intuitive way, the effects of radiation reaction can help to accelerate charge particles under some specific conditions. (author)