Analytical bunch compression studies for FLUTE

TL;DR

This paper presents analytical models for bunch compression in FLUTE, comparing them with simulations, and discusses effects like space charge and CSR to aid future studies of electron bunch compression.

Contribution

It introduces analytical models for FLUTE's bunch compressor, including effects of geometry, space charge, and CSR, validated against simulations.

Findings

Analytical results agree well with simulations for geometric and CSR effects.

Space charge effects are overestimated in the analytical model for large bunch charges.

The study provides a foundation for future analytical research on bunch compression.

Abstract

The current article deals with analytical bunch compression studies for FLUTE whose results are compared to simulations. FLUTE is a linac-based electron accelerator with a design energy of approximately 40 MeV currently being constructed at the Karlsruhe Institute of Technology. One of the goals of FLUTE is to generate electron bunches with their length lying in the femtosecond regime. In the first phase this will be accomplished using a magnetic bunch compressor. This compressor forms the subject of the studies presented. The paper is divided into three parts. The first part deals with pure geometric investigations of the bunch compressor where space charge effects and the back reaction of bunches with coherent synchrotron radiation (CSR) are neglected. The second part is dedicated to the treatment of space charge effects and the third part gives some analytical results on the emission of CSR. The upshot is that the results of the first and the third part agree quite well with what is obtained from simulations. However, the space charge forces in the analytical model of the second part have the trend to be overestimated for large bunch charges. With this paper we intend to form the basis for future analytical studies of the FLUTE bunch compressor and of bunch compression, in general.