Mode couplings in a twostream freeelectron laser with a helical wiggler and an ionchannel guiding
Abstract
In this study, the method of perturbation has been applied to obtain the dispersion relation (DR) of a twostream freeelectron laser (FEL) with a helical wiggler and an ionchannel with all relativistic effects on waves. This DR has been solved numerically to find the unstable modes and their growth rate. Numerical solutions of DR show that the growth rate is considerably enhanced in comparison with singlestream freeelectron laser. In group II orbits, with relatively large wiggler induced velocities, new couplings are found. The effect of the velocity difference of the two electron beams on the instabilities has also been investigated in this study. Moreover, the effect of the ionchannel density on the maximum growth rate of FEL resonance has been analyzed.
 Authors:
 Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)
 Publication Date:
 OSTI Identifier:
 22303763
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPARATIVE EVALUATIONS; COUPLINGS; DISPERSION RELATIONS; ELECTRON BEAMS; FREE ELECTRON LASERS; NUMERICAL SOLUTION; PERTURBATION THEORY; RELATIVISTIC RANGE; STREAMS
Citation Formats
Mohsenpour, Taghi, Email: mohsenpour@umz.ac.ir, and Alirezaee, Hajar. Mode couplings in a twostream freeelectron laser with a helical wiggler and an ionchannel guiding. United States: N. p., 2014.
Web. doi:10.1063/1.4892958.
Mohsenpour, Taghi, Email: mohsenpour@umz.ac.ir, & Alirezaee, Hajar. Mode couplings in a twostream freeelectron laser with a helical wiggler and an ionchannel guiding. United States. doi:10.1063/1.4892958.
Mohsenpour, Taghi, Email: mohsenpour@umz.ac.ir, and Alirezaee, Hajar. 2014.
"Mode couplings in a twostream freeelectron laser with a helical wiggler and an ionchannel guiding". United States.
doi:10.1063/1.4892958.
@article{osti_22303763,
title = {Mode couplings in a twostream freeelectron laser with a helical wiggler and an ionchannel guiding},
author = {Mohsenpour, Taghi, Email: mohsenpour@umz.ac.ir and Alirezaee, Hajar},
abstractNote = {In this study, the method of perturbation has been applied to obtain the dispersion relation (DR) of a twostream freeelectron laser (FEL) with a helical wiggler and an ionchannel with all relativistic effects on waves. This DR has been solved numerically to find the unstable modes and their growth rate. Numerical solutions of DR show that the growth rate is considerably enhanced in comparison with singlestream freeelectron laser. In group II orbits, with relatively large wiggler induced velocities, new couplings are found. The effect of the velocity difference of the two electron beams on the instabilities has also been investigated in this study. Moreover, the effect of the ionchannel density on the maximum growth rate of FEL resonance has been analyzed.},
doi = {10.1063/1.4892958},
journal = {Physics of Plasmas},
number = 8,
volume = 21,
place = {United States},
year = 2014,
month = 8
}

A linear theory of twostream free electron laser (FEL) with helical wiggler and ion channel guiding is presented. The dispersion relation is obtained with the help of fluid theory and the growth rate is analyzed through the numerical solutions. The considerable enhancement of the growth rate is demonstrated due to the twostream instability and continuous tuning of peak growth rate ratio, twostream FEL compared to singlestream FEL, in terms of varying the ion channel frequency is illustrated.

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Electron trajectories and gain in freeelectron lasers with threedimensional helical wiggler and ionchannel guiding
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