Time domain analysis of wide-band superradiance and tapering-enhanced superradiance at zero-slippage conditions

Exceptionally, a bunched electron beam can get trapped by its own spontaneously emitted synchrotron undulator radiation in the self-interaction scheme of TES (Tapering Enhanced Superradiance).

In this scheme, excess radiative energy is extracted from the beam by tapering the undulator after the bunch trapping.

To avoid slippage of the radiation wavepacket away from the bunch, the interaction takes place in a waveguide with a slow group velocity mode.

Here we study the time domain waveform of the Electric Field and the radiation energy buildup in this scheme.

We compare its analytical theory and numerical simulations in an ideal exemplary setup based on a rectangular waveguide and a planar undulator