Radiation reaction cooling as a progenitor of kinetic instabilities and coherent radiation

The trajectories of relativistic particles in strong electromagnetic fields are modified by the backreaction of their own emitted radiation [1]. We examine how this modification to individual particle dynamics affects the global plasma dynamics in momentum space. Our analytical model is based on the extension of the Vlasov equation to include the Landau-Lifshitz radiation reaction force. Initially stable momentum distributions, under the right EM field conditions, evolve into kinetically unstable distributions [2,3]. This is shown for particle beams undergoing radiation cooling under different field configurations [4]. Particle-in-cell simulations, performed with OSIRIS [5,6], are employed to corroborate the theoretical models.

[1] Landau, L.D., Lifshitz, E.M. Pergamon, Oxford (1980)

[2] Cairns, R. A., et. al. Phys. Rev. Lett. 101.21 215003 (2008)

[3] Davoine, X., et al. JPP 84.3 (2018).

[4] Bilbao, P. J., Silva, L. O. to be submitted to PRL

[5] Fonseca R. A., et. al. Lect. Notes. Comput. Sc. 2331 342–51 (2002)

[6] Vranic M., et. al. Comput. Phys. Commun. 204 141-151 (2016)