Numerical Simulations of a Compact Terahertz Smith-purcell Free-electron Laser

Terahertz (THz) radiation occupies a very large portion of the electromagnetic spectrum and has generated much recent interest due to its ability to penetrate deep into many organic materials without the damage associated with ionizing radiation such as X-rays. One path for generating copious amount of tunable narrow-band THz radiation is based on the Smith-Purcell free-electron laser (SPFEL) effect first proposed by Wachtel [1]. In this paper we present the design and start-to-end simulation of a compact SPFEL. The device is based on a low energy (< 100 keV) electron accelerator capable of producing sheet electron beams needed to enhance the SPFEL interaction. The beam dynamics and electromagnetics of the SPFEL interaction are modeled using a finite-difference time-domain electromagnetic solver (VORPAL from Tech-X Corporation).