title: Free-electron laser without inversion: gain optimization and implementation scheme
abstract: We consider a scheme of two noncollinear wigglers with an intermediate magnetic drift region, constituting a free-electron laser without inversion (FELWI). Two mechanisms of phase shifts in the drift region between the wigglers owing to a series of magnetic lenses can give rise to FELWI: velocity- and angle-dependent shifts. An appropriate combination of these shifts is shown to provide the conditions for amplification without inversion. The phase shifts optimizing the gain are found. A specific scheme for the drift region is suggested.
authors.affiliation: Department of Physics, Texas A & M University, College Station, Texas 77843-4242, USA.
authors.initials: AI
authors.lastname: Artemiev
authors.initials: MV
authors.lastname: Fedorov
authors.initials: YV
authors.lastname: Rostovtsev
authors.initials: G
authors.lastname: Kurizki
authors.initials: MO
authors.lastname: Scully