Kinetic description of a wiggler-pumped ion-channel free-electron laser by applying the Einstein coefficient technique

Abstract

A kinetic theory is used to investigate the theory of a free-electron laser with a helical wiggler and an ion channel based on the Einstein coefficient method. The laser gain in the low-gain regime is obtained for the case of a cold tenuous relativistic electron beam, where the beam plasma frequency is much less than the radiation frequency, propagating in this configuration. The resulting gain equation is analyzed numerically over a wide range of system parameters.

Power enhancement via an ion-channel in a Raman free-electron laser

“…Compared to other plasmaloaded radio frequency devices, where external magnets are used, the advantage of ion-channel guiding, instead of the guide magnetic field, is that it cuts off the facility manufacture and operation expenses. Since the proof-of-principle experiments of the so-called ion-channel guiding FELs were made [26,27], a lot of papers have been devoted to this aspect, discussing the ion-hose instability, harmonic generation, satur ation mechanism, two-beam radiation, focusing peculiarity, electron's equilibrium orbits, motion chaos, beam temper ature effect, etc [28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

Kinetic description of a free electron laser with an electromagnetic-wave wiggler and ion-channel guiding by using the Einstein coefficient technique

“…The influence of finite radial geometry on the instability of a tenuous relativistic electron beam propagating in an ion-channel in a waveguide is investigated by linearized Vlasov-Maxwell equations [18]. The gain of FEL with a helical wiggler in the presence of a guiding field has also been explained by using the Einstein coefficient method [19][20]. The radiation properties of a SASE FEL with a planar wiggler have been investigated numerically by using Lienard-Wiechert fields [21].…”