DocumentCode :
1627439
Title :
Effect of Attenuation in Synchronous and Non-Synchronous Beam-Wave Interactions
Author :
Dialetis, D. ; Chernin, D. ; Antonsen, T.M., Jr. ; Levush, B.
Author_Institution :
Sci. Applications Int. Corp., McLean
fYear :
2007
Firstpage :
704
Lastpage :
704
Abstract :
Summary form only given. The gain of a traveling wave tube, in which the beam velocity is closely matched to the phase velocity of a slow circuit wave, decreases as the circuit loss increases. However, sufficiently far from synchronism an increase in circuit loss will cause an increase in gain - a phenomenon well known as the resistive wall instability. Between these extremes there are parameter regimes in which the gain is relatively insensitive to loss. A careful analytical study of a beam interacting with the slow wave fields propagating on a sheath helix, itself supported by a lossy dielectric sleeve, illustrates these effects. The central goal of this study is to determine whether the approximate treatment of circuit attenuation in the CHRISTINE ID large signal helix TWT simulation code is sufficiently accurate for the largest values of attenuation encountered in TWTs (in and near severs), for all operating voltages. Our approach has been to develop an exact small signal theory and associated code for the analysis of a beam interacting with a slow wave supported by a sheath helix. In this paper we will describe the approximate model for attenuation used in CHRISTINE as well as the exact ID small signal model. Numerical results from both models and comparisons using a C-band helix TWT will be presented.
Keywords :
travelling wave tubes; 1D small signal model; C-band helix TWT; CHRISTINE simulation code; approximate model; attenuation effect; nonsynchronous beam-wave interactions; resistive wall instability; sheath helix; slow wave fields; small signal theory; synchronous beam-wave interactions; traveling wave tube; Attenuation; Circuit simulation; Dielectric losses; Educational institutions; Laboratories; Propagation losses; Signal analysis; USA Councils; Voltage;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Plasma Science, 2007. ICOPS 2007. IEEE 34th International Conference on
Conference_Location :
Albuquerque, NM
ISSN :
0730-9244
Print_ISBN :
978-1-4244-0915-0
Type :
conf
DOI :
10.1109/PPPS.2007.4346010
Filename :
4346010
Link To Document :
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