Investigation of the electron trajectories and gain regimes of the whistler pumped free-electron laser

Journal Article · Mon Apr 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4802801· OSTI ID:22130467

Jafarinia, F.; Jafari, S. ^[1]; Mehdian, H. ^[2]

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1. Department of Physics, University of Guilan, Rasht 41335-1914 (Iran, Islamic Republic of)
2. Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, Tehran 15614 (Iran, Islamic Republic of)

A free-electron laser (FEL) scheme, which employs the whistler wave as a slow electromagnetic wave wiggler, was studied theoretically. Subjected to the transverse fields of whistler wave wiggler, the beam electrons are the source of the energy needed to produce electromagnetic radiation. The strength and the period of the wiggler field depend on the parameters of the magnetoplasma medium. This configuration has a higher tunability by controlling the plasma density, on top of the {gamma}-tunability of the conventional FELs. The theory of linear gain and electron trajectories was presented and four groups (I, II, III, and IV) of electron orbits were found in the presence of an axial guide magnetic field. Using perturbation analysis, it is found that these groups of orbits were stable except small regions of group I and IV orbits. The function {Phi} which determines the rate of change of axial velocity with beam energy was also derived. In the case in which {Phi}<0 represents a negative-mass regime in which the axial velocity accelerates as the electrons lose energy. Numerical solutions showed that by increasing the cyclotron frequency, the gain for group I and III orbits increased, while a gain decrement was obtained for group II and IV orbits.

• OSTI ID: 22130467
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM-PLASMA SYSTEMS
CYCLOTRON FREQUENCY
ELECTRON BEAMS
ELECTRONS
FREE ELECTRON LASERS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
NEGATIVE MASS
NUMERICAL ANALYSIS
NUMERICAL SOLUTION
ORBITS
PERTURBATION THEORY
PLASMA DENSITY
PLASMA INSTABILITY
RELATIVISTIC RANGE
TRAJECTORIES
TRANSPORT THEORY
VELOCITY
WAVE PROPAGATION
WHISTLERS