Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Wave-particle interactions in a long traveling wave tube with upgraded helix

Full text
Author(s):
de Sousa, M. C. [1, 2] ; Doveil, F. [2] ; Elskens, Y. [2] ; Caldas, I. L. [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Inst Fis, BR-05508090 Sao Paulo - Brazil
[2] Aix Marseille Univ, CNRS, UMR 7345 PIIM, F-13397 Marseille - France
Total Affiliations: 2
Document type: Journal article
Source: Physics of Plasmas; v. 27, n. 9 SEP 2020.
Web of Science Citations: 0
Abstract

We investigate the interaction of electromagnetic waves and electron beams in a 4 m long traveling wave tube (TWT). The device is specifically designed to simulate beam-plasma experiments without appreciable noise. This TWT presents an upgraded slow wave structure (SWS) that results in more precise measurements and makes new experiments possible. We introduce a theoretical model describing wave propagation through the SWS and validated by the experimental dispersion relation, impedance, and phase and group velocities. We analyze nonlinear effects arising from the beam-wave interaction, such as the modulation of the electron beam and the wave growth and saturation process. When the beam current is low, the wave growth coefficient and saturation amplitude follow the linear theory predictions. However, for high values of current, nonlinear space charge effects become important and these parameters deviate from the linear predictions, tending to a constant value. After saturation, we also observe trapping of the beam electrons, which alters the wave amplitude along the TWT. (AU)

FAPESP's process: 15/05186-0 - Bifurcations and control of chaos in wave-particle interactions
Grantee:Meirielen Caetano de Sousa
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 13/01335-6 - Controlling chaos in Wave-Particle interactions
Grantee:Meirielen Caetano de Sousa
Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
FAPESP's process: 11/20794-6 - Chaos in magnetized relativistic systems: regular acceleration and control of chaos
Grantee:Meirielen Caetano de Sousa
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 18/03211-6 - Non linear dynamics
Grantee:Iberê Luiz Caldas
Support Opportunities: Research Projects - Thematic Grants