THEORY OF SPONTANEOUS RADIATION BY ELECTRONS IN A TRAJECTORY-COHERENTAPPROXIMATION

The first-order quantum correction for the characterization of spontan eous radiation is calculated by means of electron quasi-classical traj ectory-coherent states in an arbitrary electromagnetic field. Well kno wn expressions for the characterization of spontaneous radiation are o btained using quasi-classical approximation. The first-order quantum c orrection is derived as a functional from a classical trajectory (amon g which is a classical spin vector). Transitions with spin hip and wit hout spin dip are distinguished. Those elements connected with photon kick and quantum motion characteristics are selected for first-order q uantum correction. It is shown that, using an ultra-relativistic appro ximation, the latter may be ignored, but when using a non-relativistic approximation their contributions are approximately equal. A special trajectory-coherent representation that significantly simplifies the i nvestigation of spontaneous radiation is proposed.