Bunch Shaping in Electron Linear Accelerators

TL;DR

This paper reviews recent advances in controlling electron beam distributions in linear accelerators, focusing on shaping techniques at the mesoscopic scale to enable new scientific and technological applications.

Contribution

It provides a comprehensive overview of experimental and theoretical methods for electron-bunch shaping using external fields and self-interactions, highlighting recent progress.

Findings

Development of new beam shaping techniques

Enhanced control over beam distribution shapes

Potential applications in advanced accelerator science

Abstract

Modern electron linear accelerators are often designed to produce smooth bunch distributions characterized by their macroscopic ensemble-average moments. However, an increasing number of accelerator applications call for finer control over the beam distribution, e.g., by requiring specific shapes for its projection along one coordinate. Ultimately, the control of the beam distribution at the single-particle level could enable new opportunities in accelerator science. This review discusses the recent progress toward controlling electron beam distributions on the "mesoscopic" scale with an emphasis on shaping the beam or introducing complex correlations required for some applications. This review emphasizes experimental and theoretical developments of electron-bunch shaping methods based on bounded external electromagnetic fields or via interactions with the self-generated velocity and radiation fields.