Unstable coupled-mode structures in a one-dimensional Raman free-electron laser
- Department of Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)
The dispersion relation of a free-electron laser (FEL) with a one-dimensional helical wiggler and an axial guide magnetic field, in the collective regime, is used to study interactions among all possible waves. In group II orbits, with relatively large wiggler induced velocities, new couplings between the negative and positive-energy space-charge waves as well as between the right and left circularly polarized electromagnetic waves are found. These instabilities are found to be distinct from the usual FEL resonance. The space-charge wave was not found to be intrinsically unstable when it couples to the electromagnetic wave and the coupling to the radiation was found to be the only way that makes it unstable.
- OSTI ID:
- 20975002
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 14; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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