Author: Price, M.J.
Paper Title Page
A New 4D Model of Short-pulse FEL Oscillators  
  • J. Blau, K. R. Cohn, W.B. Colson, M.J. Price
    NPS, Monterey, California, USA
  Funding: This work has been supported by the Office of Naval Research and the High Energy Laser Joint Technology Office.
At the Naval Postgraduate School, we have recently developed a new 4D (x,y,z,t) model for FEL oscillators where the pulse length is comparable to the slippage distance. The model follows multiple transverse and longitudinal optical modes over many passes through a resonator, including the effects of diffraction, pulse slippage and desynchronism. The code is parallelized to run on a cluster computer, and the resonator optics are self-contained, so no external optics program is necessary. The mirrors and the electron beam can be shifted or tilted off-axis to study misalignment effects. This new model is useful for studying the combined effects of longitudinal and transverse modes, the trapped particle instability, and the development of sidebands. The model is currently being validated by comparison to analytic formulas and other FEL codes, as well as existing and proposed FEL experiments. Results of these studies and examples of various effects that this new model can be used to understand will be presented.