A novel THz generation scheme based on plasma-beam interaction

A novel scheme to produce ultra-high-current (tens of kA) electron bunch trains with tunable picosecond spacing for the generation of high-power THz sources is proposed. In this scheme, an electron beam passes through a plasma section and interacts with self-excited nonlinear plasma wake to gain a periodic “sawtooth” energy modulation. Such energy modulation is then effectively converted into a beam density modulation by means of magnetic optics forming microbunches with a high charge up to a few nC and a bunching factor as high as ∼0.8. A tunable tens to hundreds of mJ level narrow-band THz radiation could be generated. This scheme can be realized in future accelerator facilities with repetition rate on the order of kHz to MHz, which provides great potential in modern science and related technologies.