Abstract
In a quantum mechanical description of the free-electron laser (FEL) the electrons jump on discrete momentum ladders, while they follow continuous trajectories according to the classical description. In order to observe the transition from quantum to classical dynamics, it is not sufficient that many momentum levels are involved. Only if additionally the initial momentum spread of the electron beam is larger than the quantum mechanical recoil, caused by the emission and absorption of photons, the quantum dynamics in phase space resembles the classical one. Beyond these criteria, quantum signatures of averaged quantities like the FEL gain might be washed out.
Highlights
An free-electron laser (FEL) is considered as a device that can be fully described within classical physics
An FEL is considered as a device that can be fully described within classical physics
We analyze the transition from quantum to classical in a low-gain FEL by contrasting the dynamics of an electron in phase space with the corresponding classical description
Summary
An FEL is considered as a device that can be fully described within classical physics. There exists a “quantum regime” [1,2,3] where quantum mechanics is mandatory for an accurate description of the FEL dynamics. We analyze the transition from quantum to classical in a low-gain FEL by contrasting the dynamics of an electron in phase space with the corresponding classical description. We find that the occurrence of quantum effects depends on the quantum mechanical recoil, caused by the absorption and emission of photons: A small recoil energy, compared to the coupling to the fields, and a small recoil momentum, compared to the initial momentum spread, are necessary to observe a classical evolution of the Wigner function. We study quantum corrections to the FEL gain
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.