Stable and Scalable Multistage Terahertz-Driven Particle Accelerator

Particle accelerators that use electromagnetic fields to increase a charged particle's energy have greatly advanced the development of science and industry since invention. However, enormous cost size conventional radio-frequency limited their accessibility. Here we demonstrate mini-accelerator powered by terahertz pulses with wavelengths 100 times shorter than pulses. By injecting short relativistic electron bunch 30-mm-long dielectric-lined waveguide tuning frequency 20-period pulse phase-velocity-matched value, precise sustained acceleration for nearly 100% electrons is achieved beam spread essentially unchanged. Furthermore, accurately controlling phase two pulses, stably accelerated successively in dielectric waveguides close charge coupling efficiency. Our results stable scalable multistage pave way functioning terahertz-driven high-energy accelerators.