Comparison Between Pierce Equivalent Circuit and Recent Discrete Model for Traveling-Wave Tubes

Damien F G Minenna (1, 2, 3) , Artem G Terentyuk (4) , Frédéric André (3) , Yves Elskens (2) , Nikita M. Ryskin (5)

1 CNES - Centre National d'Études Spatiales [Toulouse]
2 PIIM - Physique des interactions ioniques et moléculaires
3 Thales Electron Devices
4 Chernyshevsky Saratov National Research State University [Saratov]
5 Dept nonlinear physics

To perform accurate numerical simulations of the traveling-wave tube in time domain, a new approach using field decomposition with large reduction of degrees-of-freedom has been proposed: the discrete model. To assess its validity, we compare it with the well-established Pierce equivalent circuit model in small signal regime. We also discuss associated beam, circuit-beam, and circuit impedances. We demonstrate analytically and with a numerical example that the newly developed discrete model is very close to the Pierce model. Interestingly, small deviations do exist at the edges of the amplification band. We speculate that the deviation from reality is on the Pierce model side, while the discrete model would be more accurate.

Mots clés: Discrete model; Pierce model; equivalent circuit; dispersion relation; impedances; coupled mode; wave-particle interaction; traveling-wave tube (TWT); time domain; frequency domain; passband; band edge

Domaines: Electromagnétisme; Physique des plasmas [physics.plasm-ph]; Physique Classique [physics.class-ph]

Damien F G Minenna, Artem G Terentyuk, Frédéric André, Yves Elskens, Nikita M. Ryskin. Comparison Between Pierce Equivalent Circuit and Recent Discrete Model for Traveling-Wave Tubes. 2017. ⟨hal-01630803v1⟩