Suppression of terahertz radiation in electron beams with longitudinal density modulation

Electron beams with periodic longitudinal density modulation may produce terahertz radiation in linear accelerators. While terahertz radiation is useful for a wide range of applications and research interests, in some cases it may be desirable to suppress unwanted terahertz radiation caused by unintended fluctuations in the longitudinal density of an electron beam. This study explores the possibility of using a wiggler to convert the density modulation to energy modulation. Simulations are performed using PARMELA. Simulated beams with only density modulation are inserted into a linear accelerator to see how the density and resulting energy modulation evolve. Results provide a better understanding of the evolution of modulated electron beams and may provide a method to suppress unwanted terahertz radiation. Parameters in the simulations are chosen to correspond to existing accelerator systems so that the results may be used to support an experimental study.