On the diffraction of a pulse by a half-plane

Abstract

The physical properties of the solution in the diffraction of an electromagnetic pulse by a perfectly conducting half-plane are studied from the standpoint of energy propagation. The form of the energy current lines and of the level lines of the energy density is given, for several instants of time after the arrival of the main part of the incident pulse at the half-plane. The splitting of the incident wave front into a transmitted and a reflected one leads to the formation of an energy reservoir near the edge. The energy contained in this reservoir is then re-emitted, giving rise to the diffracted pulse. Lines of zero energy current play an important role in this process; their formation and evolution is discussed, as well as the growth of the diffracted wave front. The asymptotic behaviour of the diffracted pulse for large times is considered.