Quantum effects in spontaneous emission by a relativistic, undulating electron beam

G. R. M. Robb, R. Bonifacio

Research output: Contribution to journalArticle

11 Citations (Scopus)


Current models of the effect of spontaneous emission on the electron beam dynamics neglect the discreteness of electron recoil associated with photon emission. We present a novel, one-dimensional model of the effect of spontaneous emission on the electron beam dynamics in an undulator both in the classical regime where discrete electron recoil is negligible, and in the quantum regime where it is significant. It is shown that in the classical regime, continuous decrease of the average electron energy and diffusive growth of the electron energy spread occurs, in agreement with previous classical models. In the quantum regime, it is shown that the evolution of the electron momentum distribution occurs as discrete momentum groups according to a Poisson distribution. The narrow momentum features of the quantum regime may be useful for generation of coherent radiation, which relies on electron beams having sufficiently narrow momentum/energy distributions.

Original languageEnglish
Article number34002
Number of pages5
JournalEPL: A Letters Journal Exploring the Frontiers of Physics
Issue number3
Publication statusPublished - May 2011


  • lasers
  • electron beam

Cite this