MODE-SELECTIVE AMPLIFICATION IN A WAVE-GUIDE FREE-ELECTRON LASER WITHA 2-SECTIONED WIGGLER

Authors
Citation
Mg. Kong, MODE-SELECTIVE AMPLIFICATION IN A WAVE-GUIDE FREE-ELECTRON LASER WITHA 2-SECTIONED WIGGLER, IEEE transactions on plasma science, 26(1), 1998, pp. 85-91
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Phsycs, Fluid & Plasmas
ISSN journal
0093-3813
Volume
26
Issue
1
Year of publication
1998
Pages
85 - 91
Database
ISI
SICI code
0093-3813(1998)26:1<85:MAIAWF>2.0.ZU;2-G
Abstract
One important issue,in waveguide free electron lasers (FEL's) involves an interaction of the electron beam with one waveguide mode at two di fferent resonant frequencies, Since the low-frequency mode often has a higher gain, the usually preferred high-frequency mode is suppressed as a result of mode competition, In this paper, possible control of th is mode competition is considered using a nonstandard wiggler magnet c onsisting of two cascaded wiggler sections with different periods and field strengths, It is demonstrated that with an appropriate, differen tiation between the two wiggler sections the high-frequency mode may b e amplified preferentially, This mode-selective amplification may be u sed to suppress the low-frequency mode, A small signal gain formulatio n is developed for a waveguide FEL with such a two-sectioned wiggler a rrangement and numerical examples are used to demonstrate its applicab ility to mode control in waveguide FEL's, Effects of wiggler field err ors and electron energy spread are also considered, It is shown that t he requirement for wiggler field errors and electron energy spread in the two-sectioned wiggler arrangement is similar to that in the usual straight wiggler configuration.