Nonlinear theory and experiment of collective free electron lasers

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859488· OSTI ID:6733706

Wurtele, J S; Chu, R ^[1]; Fajans, J ^[2]

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1. Department of Physics, Massachusetts Institute of Technology, Cambridge, MA (USA) Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, MA (USA)
2. Department of Physics, University of California-Berkeley, Berkeley, CA (USA)

A theoretical and experimental study of the nonlinear performance of a free electron laser (FEL) amplifier operating in the collective (Raman) regime is reported. The FEL generates up to {similar to}100 kW of rf power at a frequency of 9.3 GHz and an efficiency of {similar to}10%. Power saturation, efficiency, and synchrotron oscillations are studied as a function of rf input power, electron beam energy, current, wiggler field amplitude, and axial distance within the helical wiggler. The influences of the nonlinear electron motion in the ponderomotive potential and space-charge waves are studied by measurements of the dependence of gain and efficiency on the initial radiation intensity. Good agreement with a nonlinear theory that takes cognizance of electron trapping in the combined ponderomotive and space-charge potential well is obtained.

• OSTI ID: 6733706
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 2:7; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426002* -- Engineering-- Lasers & Masers-- (1990-)
AMPLIFICATION
AMPLIFIERS
BEAM CURRENTS
BREMSSTRAHLUNG
CORRELATIONS
CURRENTS
DIFFERENTIAL EQUATIONS
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELECTROMAGNETS
ELECTRONIC EQUIPMENT
EQUATIONS
EQUATIONS OF MOTION
EQUIPMENT
FREE ELECTRON LASERS
FREQUENCY RANGE
GAIN
GHZ RANGE
GHZ RANGE 01-100
LASERS
MAGNETS
MICROWAVE RADIATION
NONLINEAR PROBLEMS
OPERATION
PARTIAL DIFFERENTIAL EQUATIONS
PERFORMANCE
POWER
RADIATIONS
RAMAN EFFECT
SATURATION
SPACE CHARGE
SYNCHROTRON RADIATION
TRAJECTORIES
WIGGLER MAGNETS