Self-fields in free-electron lasers with planar wiggler and ion-channel guiding

• Published in: Journal of physics. D, Applied physics Vol. 39; no. 17; pp. 3742 - 3748
• Main Authors: Farokhi, B, Jafary, F B, Maraghechi, B
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.09.2006; Institute of Physics
• Subjects: Electromagnetism; electron and ion optics; Exact sciences and technology; Free-electron lasers; Fundamental areas of phenomenology (including applications); Physics; Radiation by moving charges; Ion channeling; Free electron lasers; Numerical solution; Theoretical study; Relativistic electron; Orbits; Steady state solution
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/39/17/005

A theory of self-electric and self-magnetic fields of a relativistic electron beam passing through a one-dimensional planar wiggler and an ion-channel is presented. The equilibrium orbits and their stability, under the influence of self-electric and self-magnetic fields, are analysed. New unstable orbits, in the first part of the group I orbits, are found. It is shown that for a low energy and high density beam the self-fields can produce very large effects. Stabilities of quasi-steady-state orbits are investigated by analytical and numerical methods and perfect agreement was found. The theory of small signal gain is used to derive a formula for the gain with the self-field effects included. A numerical analysis is conducted to study the self-field effects on the quasi-steady-state orbits and the gain.