Demonstration of nonlinear-energy-spread compensation in relativistic electron bunches with corrugated structures

TL;DR

This paper demonstrates how corrugated structures can effectively compensate for nonlinear energy spread in relativistic electron bunches, improving beam quality for accelerator applications.

Contribution

It introduces a method using orthogonal corrugated structures to reduce energy spread and cancel quadrupole wake fields in low charge, low energy electron beams.

Findings

Significant reduction in beam energy spread achieved.

Quadrupole wake fields effectively canceled with orthogonal structures.

Extended application to low charge and low energy regimes.

Abstract

High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wake fields which otherwise increase beam emittance can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.