Acceleration of charged particles and radiation-reaction in strong plane and spherical waves

Abstract

A comparison between the acceleration of charged particles in plane and spherical waves including the effect of radiation reaction is given. In strong electromagnetic waves the charged particle stays initially at practically constant phase — “phase locked” part of the motion — and only after it has travelled many wavelengths does the wave overtake the particle. During the phase-locked part of the motion depending upon the initial conditions of how a particle is injected into the wave radiation reaction can lead to both a net energy gain or loss compared to the motion without radiation reaction. In a plane wave however radiation reaction always leads to a net energy gain if it can build up long enough. A test of this latter prediction by means of ultra-strong lasers might be possible.