
Accession Number : ADA134458
Title : The Evolution of Spontaneous and Coherent Radiation in the Free Electron Laser Oscillator.
Descriptive Note : Interim rept.,
Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC
Personal Author(s) : Sprangle,P ; Tang,C M ; Bernstein,I
PDF Url : ADA134458
Report Date : 16 Aug 1983
Pagination or Media Count : 40
Abstract : An analysis of the free electron laser (FEL) oscillator startup problem in the linear regime is presented. The model is spatially one dimensional, though many important three dimensional effects are included heuristically. The electron beam consists of pulses of arbitrary shape separated by approximately twice the radiation transit time. The small gain/pass approximation is employed in deriving an energy rate equation, which described the evolution of the radiation pulses within the resonator. The wiggler field is assumed to occupy a portion of the finite Q resonator. In the energy rate equation, the spontaneous (incoherent) radiation term is represented by a source matrix, while the stimulated (coherent) radiation term is represented by a gain matrix. The effect of small variations in the mirror separation are investigated in the context of laser lethargy. Our analysis suggests possible methods which would substantially shorten the startup times in FEL oscillators. Finally, our results are compared with the FEL oscillator experiments performed at Stanford University. (author)
Descriptors : *Electrical lasers, *Starting, *Pulsed lasers, *Oscillators, *Electron beams, Coherent radiation, Emission spectra, Free electrons, Approximation(Mathematics), Linear systems, Three dimensional, Mirrors, Variations, Pulses, Rates, Radiation, Energy, Lasers, Sources, Separation, Time, Gain, Equations
Subject Categories : Lasers and Masers
Particle Accelerators
Distribution Statement : APPROVED FOR PUBLIC RELEASE