Resonant amplification of a slow Langmuir wave in a relativistic electron beam
Abstract
Interaction is considered between a relativistic electron beam and a wave excited by an external source in a slow wave structure when the initial amplitude of the wave is nonzero. Efficient acceleration of the Langmuir mode occurs at resonance, when the parameters of the external wave satisfy the dispersion relation for the slow Langmuir mode. That is, the amplitude of the axial electric wave field in the beam-retarding structure system increases linearly with time and along the axis of the system. Two methods are developed for describing the resonant interaction, including the nonlinear behavior. The parameters describing the interaction are estimated, and it is found that the resonant interaction provides a highly efficient mechanism for producing deep spatial modulation of the density in a relativistic electron beam or in electromagnetic waves of amplitude greater than 100 kV/cm with a low phase velocity.
- Publication:
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Soviet Physics Technical Physics
- Pub Date:
- June 1983
- Bibcode:
- 1983SPTP...28..639B