CERN Accelerating science

Article
Title	Gain and Coherent Radiation from a Smith-Purcell Free-Electron Laser
Author(s)	Brau, Charles A ; Andrews, Heather L ; Boulware, Charles H ; Jarvis, Jonathan D
Affiliation	(Vanderbilt/DPA, Nashville - Tennessee)
Publication	2004
In:	26th International Free Electron Laser Conference and 11th FEL User Workshop 2004, Trieste, Italy, 29 Aug - 3 Sep 2004, pp.e-proc. THPOS60
Subject category	Accelerators and Storage Rings
Abstract	We have developed a new theory to describe the gain of a Smith-Purcell FEL. The theory shows that the electrons interact with an evanescent mode whose frequency lies slightly below the frequency range of Smith-Purcell radiation, and whose group velocity is negative. Computations indicate that very high gain should be observed even at very low current with suitable bright electron beams. An experiment is under construction to test these predictions.