Ginzburg-Landau model for mode competition and single-mode operation of a free-electron laser

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics

DOI:https://doi.org/10.1103/PhysRevE.58.3826· OSTI ID:641623

Ng, C S; Bhattacharjee, A ^[1]

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1. Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242 (United States)

Mode competition of a free-electron laser is modeled by the Ginzburg-Landau equation. The stability of a single-mode solution is analyzed, and connections are established with known instabilities of the Ginzburg-Landau equation. It is found that the principal mode with the largest gain is always stable and hence there is no Benjamin-Feir instability. However, the Eckhaus (or phase) instability generally occurs if the frequency of a mode lies outside of a designated range centered on the principal mode. Under certain conditions, the Eckhaus instability can cause a sudden chaotization and spikiness in the radiation field. Analytical criteria and scaling for single-mode operation are given and tested by numerical simulations. A theoretical controversy on single-mode operation of the free-electron laser at the University of California at Santa Barbara is resolved. {copyright} {ital 1998} {ital The American Physical Society}

• OSTI ID: 641623
• Journal Information: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, Journal Name: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics Journal Issue: 3 Vol. 58; ISSN PLEEE8; ISSN 1063-651X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
ELECTRON BEAMS
FREE ELECTRON LASERS
GINZBURG-LANDAU THEORY
SCALING LAWS
STABILITY