Electron beam induced THz emissions from nanotube array

A new scheme of terahertz radiation generation by passing an ultrashort electron bunch over a planar array of nanotube/nanorod across their lengths is proposed and analyzed. The beam pulse exerts a repulsive impulse on the free electron cylinder of each nanorod and displaces them with respect to ion cylinder. After the passage of the pulse, the electron cylinders oscillate at their natural frequency ωp/2 (where ωp is the plasma frequency of electrons in each carbon nanotube) acting as phased array dipole antennae, emitting THz radiation.