Synchrotron radiation and symmetries

The total power of radiation emitted by a monoenergetic electron in circula r orbit is derived by calculating the instantaneous energy flux of the elec tron field across the surfaces of spheres and tori that enclose the orbit. These surfaces are such that the positions of the electron at different tim es are indistinguishable with respect to them, which in turn permits the ch oice of special spheres and tori that greatly simplify the calculations. Th e total power of radiation of an electron is usually derived in textbooks w ith the help of the relativistic formalism. But for the particular motion i n a synchrotron, the total power of radiation is obtained here working in t he ordinary three-dimensional physical space, where the calculations are co nceptually easier to follow than in Minskowski space, especially for studen ts who are taking a first course of electrodynamics. (C) 2000 American Asso ciation of Physics Teachers.