Acceleration

Physics

Accelerator physics

Electron

Phase velocity

Terahertz radiation

Optics

Beam (structure)

Particle accelerator

Nuclear physics

Waveguide

Relativistic electron beam

Pulse (music)

Particle beam

Computer science

Phase (matter)

Quantum mechanics

Radio frequency

Classical mechanics

Telecommunications

Detector

Cathode ray

Physical Review Letters

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

Stable and Scalable Multistage Terahertz-Driven Particle Accelerator