Nonlinear study on Raman regime free electron laser with elliptical waveguide

Abstract

A free electron laser (FEL) amplifier with an elliptical waveguide and a planar wiggler is proposed. A set of coupled operating equations for this FEL operating in the Raman regime is derived using three-dimensional nonlinear theory. The numerical simulation code is developed, and the characteristics of this FEL amplifier are analysed numerically. Our numerical simulations are conducted to model a 34.6 GHz amplifier with an electron beam with an energy of 3.1 MeV. The results indicate that the elliptical waveguide is more suitable for a FEL with a planar wiggler system than a rectangular waveguide.

Mixing and space-charge effects in free-electron lasers

“…In this case, not only the relaxation is delayed with respect to Compton approximations, 11 but also the way the system relaxes reveals new features associated with the presence of density waves. As far as particle dynamics is concerned, the setting is relatively similar to the wave-breaking process in the case of magnetically focused charged beams.…”

Growth rate for free-electron lasers through a warm beam layered model

“…The process makes the radiation grow exponentially until nonlinear effects, such as the space-charge, begin to dominate the system dynamics (Sprangle, Tang & Manheimer 1980; Bonifacio et al. 1990; Seo & Choi 1997; Wang, Xiao & Liang 2006; Monteiro et al. 2013; Peter et al.…”

“…If the initial conditions (energy of the beam, wavelengths of the fields and wiggler field amplitude) are correct, as the electrons are entrapped by the ponderomotive potential, they lose energy and deliver this energy to the laser field. The process makes the radiation grow exponentially until nonlinear effects, such as the space-charge, begin to dominate the system dynamics (Sprangle, Tang & Manheimer 1980;Bonifacio et al 1990;Seo & Choi 1997;Wang, Xiao & Liang 2006;Monteiro et al 2013;Peter et al 2013;Peter, Endler & Rizzato 2014).…”