This paper studies the characteristics of an ultrarelativistic charged particle in a general, large-scale, electromagnetic field, taking into consideration the effects of strong radiative damping. Formal solutions of the Lorentz-Dirac equation in an arbitrary external field are given. They are applied to cases of astrophysical interest. The final energy of the particle and the rate and characteristic frequency of the radiation are derived.

• Received 31 August 1977

DOI:https://doi.org/10.1103/PhysRevD.17.434