Quasilinear theory of radiation saturation in a free-electron laser

Journal Article · Sun Apr 15 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.345308· OSTI ID:6900550

Marable, W P ^[1]; Sprangle, P A ^[2]

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1. University of Maryland, Department of Physics and Astronomy, College Park, Maryland 20742 (USA)
2. Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (USA)

A quasilinear theory of the self-consistent evolution of the electron-beam distribution and radiation field within a free-electron laser is presented. The relativistic electron beam propagates through an ideal helical wiggler {bold B}{sub 0}={minus}{ital B}{sub {ital w}}(cos {ital k}{sub {ital w}}{ital z}{ital {cflx e}}{sub {ital x}}+sin {ital k}{sub {ital w}}{ital z}{ital {cflx e}}{sub {ital y}}), for which the transverse gradients {partial derivative}/{partial derivative}{ital x}=0={partial derivative}/{partial derivative}{ital y} have been neglected. The transverse variation of both the transverse-polarized radiation field and the electron-beam distribution have also been neglected. Additionally, the electron beam is assumed to be sufficiently tenuous that the longitudinal space-charge potential {delta}{phi} is negligible and the Compton approximations are applicable. The resulting asymptotic expression for the spectral energy density is used to evaluate the efficiency and saturated radiation power in a variety of parameter regimes relevant to experiments.

• OSTI ID: 6900550
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:8; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426002* -- Engineering-- Lasers & Masers-- (1990-)
ASYMPTOTIC SOLUTIONS
BEAMS
BOLTZMANN-VLASOV EQUATION
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC FIELDS
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ENERGY DENSITY
ENERGY RANGE
EQUATIONS
FREE ELECTRON LASERS
LASER RADIATION
LASERS
LEPTON BEAMS
MAXWELL EQUATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE BEAMS
RADIATIONS
RELATIVISTIC RANGE
SATURATION
SELF-CONSISTENT FIELD
TIME DEPENDENCE