Terahertz surface plasmon generation on a magnetized metal column by a rotating electron-beam

The excitation of surface plasma wave (SPW) by the interaction of laser and electron beam can generate efficient terahertz (THz) radiation, which may have many applications in THz optics and imaging. In this paper, we investigate THz surface plasmons using the interaction of a rotating electron beam with a magnetized metallic surface. These fields are excited via a transverse component of the current generated in the plasma. The idea behind this research is to enhance the transverse component of the current density by coupling the plasma electrons and the free electrons on the metal surface. The finite azimuthal rotation of the electron beam on the metal surface contributes to the excitation of the SPW via stronger ponderomotive force. The magnetic field applied along the metal surface contributes via cyclotron resonance. We estimate the THz field using a reasonable theoretical model. Several scaling laws are obtained for THz field estimation and optimization. From numerical results, we conclude that a considerable THz field strength can be enhanced by employing a rotating electron beam. The peak THz field strength is estimated about 70 GV/cm of 2.5 THz frequency for 0.4 T magnetic field. This research gives a unique and feasible method to generate THz radiation with a rotating electron beam on a magnetized metal column.