Application of the green function formalism to nonlinear evolution of the low gain FEL oscillator
Abstract
A matrix formalism for the optical pulse evolution in the frequency domain, is applied to the nonlinear regime of operation. The formalism was previously developed for studies of the linear evolution of the low-gain FEL oscillator with an arbitrary shape of the electron beam. By varying experimentally controllable parameters, such as cavity detunning and cavity losses, different regimes of operation of the FEL oscillator, such as a steady state saturation and limit cycle saturation, are studied numerically. It is demonstrated that the linear supermodes, numerically obtained from the matrix formalism, provide an appropriate framework for analyzing the periodic change in the output power in the limit cycle regime. The frequency of this oscillation is related to the frequencies of the lowest-order linear supermodes. The response of the output radiation to periodic variation of the electron energy is studied. It is found that the response is enhanced when the frequency of the energy variation corresponds to the difference of per-pass phase advances of the lowest linear supermodes. Finally, various nonlinear models are tested to capture the steady state saturation and limit cycle variation of the EM field in the oscillator cavity.
- Authors:
-
- Princeton Plasma Physics Lab., NJ (United States)
- Massachusetts Institute of Technology, Cambridge, MA (United States); and others
- Publication Date:
- Research Org.:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI Identifier:
- 238701
- Report Number(s):
- BNL-61982-Absts.; CONF-9508156-Absts.
ON: DE96002729; TRN: 96:013190
- Resource Type:
- Conference
- Resource Relation:
- Conference: 17. international free electron laser conference, New York, NY (United States), 21-25 Aug 1995; Other Information: PBD: [1995]; Related Information: Is Part Of 17th international free electron laser conference and 2nd international FEL users` workshop. Program and abstracts; PB: 300 p.
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 43 PARTICLE ACCELERATORS; 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; FREE ELECTRON LASERS; GREEN FUNCTION; GAIN; NONLINEAR OPTICS; OPERATION; ELECTRON BEAMS
Citation Formats
Shvets, G, Wurtele, J S, and Gardent, D. Application of the green function formalism to nonlinear evolution of the low gain FEL oscillator. United States: N. p., 1995.
Web.
Shvets, G, Wurtele, J S, & Gardent, D. Application of the green function formalism to nonlinear evolution of the low gain FEL oscillator. United States.
Shvets, G, Wurtele, J S, and Gardent, D. 1995.
"Application of the green function formalism to nonlinear evolution of the low gain FEL oscillator". United States. https://www.osti.gov/servlets/purl/238701.
@article{osti_238701,
title = {Application of the green function formalism to nonlinear evolution of the low gain FEL oscillator},
author = {Shvets, G and Wurtele, J S and Gardent, D},
abstractNote = {A matrix formalism for the optical pulse evolution in the frequency domain, is applied to the nonlinear regime of operation. The formalism was previously developed for studies of the linear evolution of the low-gain FEL oscillator with an arbitrary shape of the electron beam. By varying experimentally controllable parameters, such as cavity detunning and cavity losses, different regimes of operation of the FEL oscillator, such as a steady state saturation and limit cycle saturation, are studied numerically. It is demonstrated that the linear supermodes, numerically obtained from the matrix formalism, provide an appropriate framework for analyzing the periodic change in the output power in the limit cycle regime. The frequency of this oscillation is related to the frequencies of the lowest-order linear supermodes. The response of the output radiation to periodic variation of the electron energy is studied. It is found that the response is enhanced when the frequency of the energy variation corresponds to the difference of per-pass phase advances of the lowest linear supermodes. Finally, various nonlinear models are tested to capture the steady state saturation and limit cycle variation of the EM field in the oscillator cavity.},
doi = {},
url = {https://www.osti.gov/biblio/238701},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 1995},
month = {Sun Dec 31 00:00:00 EST 1995}
}