J. Blau, A. Christodoulou, W. B. Colson, D. Lampiris, R. McGinnis, K. Sturgess*, S. V. Benson**, J. F. Gubeli**, G. R. Neil**
Physics Department, Naval Postgraduate School, Monterey, CA 93940 USA, * Department of Physics, USMA, West Point, NY 10996 USA, ** Free Electron Laser Department, Thomas Jefferson National Accelerator
Experiments using the TJNAF FEL have explored operation with both a tapered and
inversely tapered undulator. Multimode simulations are used to analyze the
operation describing the evolution of short optical pulses in the far infrared.
The short optical pulse presents an ever changing field strength to each section
of the electron pulse so that idealized operation is not possible. Yet,
advantages for recirculation of the electron beam can be explored.
