Fully 3D time-dependent simulation of free electron laser within an overmoded rectangular waveguide

Abstract

Numerical simulation codes are basic tools for designing Free Electron Lasers (FELs). This paper describes a numerical method for the time-dependent, three-dimensional simulation of the free electron laser (FEL) using a rectangular waveguide within overmoded configuration when the radiation wavelength is much shorter than the waveguide cut-off wavelength. Instead of developing a new code, the GENESIS simulation code is modified for our purpose. This method presented here can be used for extending the capacity of GENESIS to cover this special configuration. The major modification is to apply the metal boundary conditions on the field equations in a limited rectangular region and the full Cartesian mesh using the Alternating Direction Implicit (ADI) integration scheme to solve the field equation remains adopted.

Solving the spectral gap problem with a four-mirror bow-tie cavity in waveguide free-electron laser oscillators

“…Despite this, the waveguide FEL is distinguishable from its free-space counterpart in that its transverse field evolution is influenced by the waveguide itself 30 . Considering the conductive boundary conditions, a modified GENESIS code has been developed for the FEL using a rectangular waveguide 31 .…”

Design of a Pre-Bunched THz Free Electron Laser

“…The vacuum chamber acted as a waveguide for the THz FEL. We have modified the GENESIS code with the consideration of the conductive boundary conditions on the rectangular waveguide walls, which can be found elsewhere [18].…”