Identifying chaotic electron trajectories in a helical-wiggler free-electron laser.

Abstract

When taking into account the equilibrium self-fields of the beam, it is confirmed that the motion of an electron in a helical wiggler with guide field may be chaotic. There is evidence of chaos from numerical calculations of nonzero Lyapunov exponents using different approaches of Benettin's method which are described and compared. Very accurate Poincar\'e maps are also performed.