Electron beam shaping via laser heater temporal shaping

TL;DR

This paper explores laser heater temporal shaping as a method to control electron beam profiles in FELs, enabling high-power, high-repetition-rate operation with customizable bunch characteristics.

Contribution

It introduces a novel approach to beam shaping using laser heater modulation, supported by kinetic analysis and start-to-end simulations for FEL applications.

Findings

Laser heater shaping can control slice-energy spread and bunch current profiles.

Simulation results demonstrate effective beam shaping at LCLS-II.

Technique supports high-power, high-repetition-rate FEL operation.

Abstract

Active longitudinal beam optics can help FEL facilities achieve cutting edge performance by optimizing the beam to: produce multi-color pulses, suppress caustics, or support attosecond lasing. As the next generation of superconducting accelerators comes online, there is a need to find new elements which can both operate at high beam power and which offer multiplexing capabilities at Mhz repetition rate. Laser heater shaping promises to satisfy both criteria by imparting a programmable slice-energy spread on a shot-by-shot basis. We use a simple kinetic analysis to show how control of the slice energy spread translates into control of the bunch current profile, and then we present a collection of start-to-end simulations at LCLS-II in order to illustrate the technique.