Quantum regime of a plasma-wave-pumped free-electron laser in the presence of an axial magnetic field

Abstract

The quantum regime of a plasma-whistler-wave-pumped free-electron laser (FEL) in the presence of an axial-guide magnetic field is presented. By quantizing both the plasma whistler field and axial magnetic field, an N-particle three-dimensional Hamiltonian of quantum-FEL (QFEL) has been derived. Employing Heisenberg evolution equations and introducing a new collective operator which controls the vertical motion of electrons, a quantum dispersion relation of the plasma whistler wiggler has been obtained analytically. Numerical results indicate that, by increasing the intrinsic quantum momentum spread and/or increasing the axial magnetic field strength, the bunching and the radiation fields grow exponentially. In addition, a spiking behavior of the spectrum was observed with increasing cyclotron frequency which provides an enormous improvement in the coherence of QFEL radiation even in a limit close-to-classical regime, where an overlapping of these spikes is observed. Also, an upper limit of the intrinsic quantum momentum spread which depends on the value of the cyclotron frequency was found.

Chaotic dynamics in X-ray free-electron lasers with an optical undulator

“…The ion-channel generated by the plasma medium can also withstand high fields due to being in the ionized state and therefore overcome the restriction of material breakdown 35 , 36 . Introducing a magnetized ion-channel into the interaction region can confine the e-beam and maintain the focus of the pump wave over a significant distance 37 , 38 . The introduction of ion-channel in laser-driven-XFELs helps to reduce the e-beam energy requirement and enhances the power of X-ray pulses 38 .…”