Stable and scalable multistage terahertz-driven particle accelerator

TL;DR

This paper presents a compact, scalable terahertz-driven multistage particle accelerator that achieves stable, efficient acceleration of electrons, offering a promising alternative to traditional large-scale accelerators.

Contribution

The authors demonstrate a mini-accelerator using terahertz pulses with precise phase control, enabling stable multistage acceleration with high charge efficiency.

Findings

Achieved nearly 100% electron acceleration with unchanged energy spread.

Successfully staged acceleration in two dielectric waveguides with high charge coupling.

Demonstrated stable, scalable beam acceleration in a compact setup.

Abstract

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 mini-accelerator 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 mini-accelerator and pave the way for functioning terahertz-driven high-energy accelerators.