Abstract
Narrow, high-power ``spikes'' can be emitted by a 24-GHz free-electron laser (FEL). Spikes, \ensuremath{\sim}450 psec long, may occur randomly or in a sequence which is not the mode-locked period of the resonator. The slippage of the FEL is varied by changing the diameter of the drift tube. The slippage is zero when the electron axial speed is the same as the wave group velocity. Spiking was observed with and without slippage. Measurements of the FEL spectrum are reported and we compare the spike width with a solitary-wave theory. The experiment rules out the sideband instability or superradiance as a cause for this spiking.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have