Transition radiation of electrons with a nonzero orbital angular momentum

Abstract

Several experimental groups have recently obtained the socalled vortex electrons (electrons with orbital angular momentum (OAM) of ≤ 100) with energies of ~ 300 keV. The angular momentum of such elec� trons becomes proportional to the OAM value, which leads to the corresponding increase in the electron magnetic moment. In this work, we investigate the transition radiation from the "charge + magnetic moment" system by means of the classical electrodynamics theory. The circular polarization of optical tran� sition radiation reaches its maximum level to ~ 70%, which allows using this effect for the independent mea� surement of the electron orbital momentum value.