Manipulation and diagnosis of femtosecond relativistic electron bunch using terahertz-driven resonators

Using strong electromagnetic fields generated by lasers to interact with electrons for precise diagnosis and manipulation of electron beams represents a recent focal point in accelerator technology. This approach surpasses the limitations of conventional RF technology, such as low electric field gradients and timing jitters, effectively enhancing the accuracy of ultrafast electron beam diagnostics and manipulations. As demands for precision continue to rise, the precise diagnosis of crucial parameters of ultrafast electron beams remains challenging. This study delves into the electromagnetic behavior of THz-driven devices and proposes an all-optical method utilizing single-cycle THz radiation to compress and characterize a 3 MeV electron beam. Particle tracking simulations demonstrate an astonishing compression effect, reducing the bunch length from 54.0 fs to 4.3 fs, and achieving sub-femtosecond bunch length measurement resolution. Moreover, when combined with an orthogonal THz streak camera, this method shows even greater potential in multi-bunch scenarios.