Free electron lasers with static and dynamic plasma wigglers

Dispersion relation and growth rate of a relativistic electron beam propagating through a Langmuir wave wiggler

“…Introducing plasma into the interaction region might confine the electron beam and hold the focus of the pump wave. Presence of the plasma opens up the possibility of employing plasma eigenmodes as wigglers for the excitation of shorter wavelengths (Lalita et al 1991;Karbushev 1995;Sharma and Tripathi 1988). Joshi et al (1987) and Balakirev et al (1986) examined the possibility of employing Langmuir wave wigglers.…”

“…In such a plasma wave, the particle trajectories will be somewhat different than in the purely oscillating (ac) case. Such large amplitude relativistic plasma waves can be excited readily by laser pulses or intense electron bunches, and is being studied theoretically and experimentally by many researchers (Balakirev et al 1986;Joshi et al 1987; Sharma and Tripathi 1988;Lalita et al 1991;Yu et al 1993;Williams et al 1993;Pant and Tripathi et al 1994;Karbushev 1995;. Physically, the existence of an axial guide magnetic field in this kind of FEL can not only confine the ambient plasma, but also focus the electron beam which may result in increased efficiencies of FEL's.…”

Nonlinear study on Raman regime free electron laser with elliptical waveguide

“…The development of compact FELs, with the advantages of a small size, a low voltage and a high efficiency, has been a subject of much attention because of their many realistic applications. For this purpose, many schemes of wiggler have been proposed [6][7][8][9], but a typical wiggler utilized in FEL systems is a planar wiggler because of its simple structure. This wiggler possesses parabolically tapered pole pieces used to transverse focus the electron beam.…”