Simulation studies of the proposed far-infrared FEL amplifier at ISIR

Computer simulation studies are currently underway for the proposed FEL amplifier experiment to be carried out using the existing 38 MeV, L-band linac based FIR FEL system at the Institute of Scientific and Industrial Research (ISIR), Osaka University. This paper describes the time dependent and time independent simulation results using Genesis code. Dependence of FEL amplifier characteristics is investigated such as power spectrum and profile, frequency spectrum and FEL bunching on parameters like beam current, input power and interaction length. The operating current regime and input seed laser powers required for optimum amplification are given. Thc code has also been used to compare SASE experimental data with simulation results with a reasonably good correlation. (author)