Two and three dimension simulations of Smith–Purcell terahertz radiation using a particle-in-cell code

Although several 2-D simulations of Smith–Purcell (SP) radiation using particle-in-cell (PIC) codes have been performed, only recently have 3-D simulations been reported. To some extent this is caused by the requirements of computer memory and time, which are much greater in the latter. We present our new 3-D results concerning the simulation of the MIT experiment that used a pre-bunched 15 MeV beam to generate terahertz SP radiation. In particular, we compare the new results with our older 2-D simulations, in order to see which aspects survive in 3-D simulations. We also address the question of power radiated according to the two simulations.