Dynamical effects on superradiant THz emission from an undulator

Area of Science:

• Physics
• Quantum Optics
• Accelerator Physics

Background:

• Superradiant emission amplifies light intensity quadratically with electron count when bunch duration is shorter than emission wavelength.
• Ultra-relativistic electron bunches often develop energy chirp during compression in magnetic chicanes for undulator injection.
• Terahertz (THz) undulators utilize strong magnetic fields and dispersion to manipulate electron bunch dynamics.

Purpose of the Study:

• To investigate the impact of longitudinal phase space evolution on superradiant THz emission.
• To analyze how energy chirp in electron bunches affects THz superradiance in undulators.
• To model and simulate the superradiant THz emission from chirped electron bunches in a THz undulator.

Main Methods:

• Development of an analytical model to describe electron bunch evolution and superradiant emission.
• Utilizing particle-based simulations to study the dynamics in a THz undulator.
• Analyzing the longitudinal phase space transformations of the electron bunch.

Main Results:

• The energy chirp and subsequent phase space evolution significantly alter the conditions for superradiant emission.
• Simulations confirm the analytical model's predictions regarding the dependence of THz output on bunch dynamics.
• The interplay between undulator dispersion and electron energy chirp modifies the superradiant THz spectrum and intensity.

Conclusions:

• Electron bunch energy chirp is a critical factor influencing superradiant THz emission in undulators.
• Understanding and controlling bunch dynamics is essential for optimizing THz radiation generation via superradiance.
• This study provides insights into the physics of superradiant THz sources and their operational parameters.