SYNCHROTRON-RADIATION - AN INVERSE COMPTON-EFFECT

Synchrotron radiation in a static homogeneous magnetic field is considered from the viewpoint of inverse Compton scattering of equivalent photons in a generalization of the Fermi-Weizsacker-Williams method. The charged particle trajectory in its orbital plane is treated as a set of infinitesimal segments and, in a corresponding local Lorentz frame, the influence of each segment on the particle, is approximated by an equivalent electromagnetic wave which undergoes Compton interaction with the particle. The complex amplitudes of the scattered radiation from all elements are added coherently, on returning to the laboratory frame, to yield the total radiated intensity. This procedure successfully accounts for synchrotron radiation throughout a major fraction of the parameter space. In the classical limit it reproduces exactly all the radiation properties. In the very interesting Landau continuum limit where quantum electrodynamical modifications of the radiation properties are nevertheless important (i.e., the limit gammaB greater than or similar to 4.4 x 10(13) G and gamma much greater than 1), application of the Compton cross section provides results which are exact for spinless particles. For particles with spin there is an extra component of radiation associated with spin-flip transitions which our approach cannot take into account, but which is relatively unimportant.