Relativistic electrons in photon fields: Effects of triplet pair production on inverse Compton gamma-ray spectra

Abstract

Pair production of a photon in the Coulomb field of an electron (often referred to as triplet pair production) despite the fact that it is a third-order QED process has a cross-section that exceeds the Compton cross-section for energies of collision ≥ 250 me c2. In the present paper we re-examine the problem of ultrarelativistic electrons entering a photon field by including triplet pair production as both an energy loss and re-injection mechanism for electrons. We calculate the steady state electron distribution and photon spectrum for monoenergetic and power-law electron injections and compare them with the results one obtains in the pure Compton case, i.e. by ignoring triplet pair production.