Abstract-Generating high-power short terahertz electromagnetic pulses with multifoil radiator

Nikolay A. Vinokurov and Young Uk Jeong
http://prl.aps.org/accepted/fe071Ye2K2217a39225b2dd818ebc35e1da09eb4a
We describe a multi-foil cone radiator capable of generating high-field short terahertz pulses using short electron bunches. Round flat conducting foil plates with successively decreasing radii are stacked, forming a truncated cone with the z-axis. The gaps between the foil plates are equal and filled with some dielectric (or vacuum). A short relativistic electron bunch propagates along the z-axis. At sufficiently high particle energy, the energy losses and multiple scattering do not change the bunch shape significantly. When passing by each gap between the foil plates, the electron bunch emits some energy into the gap. Then, the radiation pulses propagate radially outward. For TEM-like waves with a longitudinal (along the z-axis) electric field and an azimuthal magnetic field, there is no dispersion in these radial lines; therefore, the radiation pulses conserve their shapes (time dependence). At the outer surface of the cone, we have synchronous circular radiators. Their radiation field forms a conical wave. Ultrashort terahertz pulses with gigawattlevel peak power can be generated with this device.