Effects of coaxial wiggler magnetic field on electron dynamics in a free-electron laser

An analysis of relativistic electron motion in a free-electron laser with coaxial wiggler and ion-channel guiding is presented. Pioncare surface-of-section maps are employed to investigate the chaotic behavior of electron motion. To obtain accurate Pioncare maps a sixth-order Runge-Kutta method with adaptive step size and Henon method are used. Pioncare surface-of-section plots show that in the presence and absence of ion-channel guiding the electron motion may be chaotic. Analysis of electron dynamics reveals that the chaotic behavior in the absence of the ion-channel guiding is due to the spatial inhomogeneities of the coaxial wiggler magnetic field.