# Acceleration of relativistic beams using laser-generated terahertz pulses

## TL;DR

This paper demonstrates the first THz-driven linear acceleration of relativistic 35 MeV electron bunches using dielectric-lined waveguides, advancing compact particle acceleration and ultrafast electron beam control.

## Contribution

It introduces a novel method for accelerating relativistic electrons with laser-generated THz pulses in dielectric structures, enabling new control and high-gradient acceleration.

## Key findings

- First THz-driven relativistic electron acceleration at 35 MeV.
- Achieved bunch compression and energy manipulation.
- Paves the way for compact THz-based accelerators.

## Abstract

Dielectric structures driven by laser-generated terahertz (THz) pulses may hold the key to overcoming the technological limitations of conventional particle accelerators and with recent experimental demonstrations of acceleration, compression and streaking of low-energy (sub-100 keV) electron beams, operation at relativistic beam energies is now essential to realize the full potential of THz-driven structures. We present the first THz-driven linear acceleration of relativistic 35 MeV electron bunches, exploiting the collinear excitation of a dielectric-lined waveguide driven by the longitudinal electric field component of polarization-tailored, narrowband THz pulses. Our results pave the way to unprecedented control over relativistic electron beams, providing bunch compression for ultrafast electron diffraction, energy manipulation for bunch diagnostics, and ultimately delivering high-field gradients for compact THz-driven particle acceleration.