Comparison study on first bunch compressor schemes by conventional and double C-chicane for MaRIE XFEL

TL;DR

This study compares conventional and double C-chicane schemes for electron bunch compression at 750 MeV in the MaRIE XFEL, showing the double C-chicane better preserves beam emittance and compensates transverse momentum shifts caused by CSR.

Contribution

It introduces a double C-chicane scheme that improves emittance preservation and CSR compensation over the conventional method for MaRIE XFEL electron bunch compression.

Findings

Double C-chicane better preserves beam emittance.

Double C-chicane compensates CSR-induced transverse momentum.

Enhanced beam quality benefits XFEL performance.

Abstract

We report our comparison study on the first stage electron bunch compression schemes at 750 MeV using a conventional and a double C-chicane for the X-ray free electron laser (XFEL) under development for the Matter-Radiation Interactions in Extremes (MaRIE) project at Los Alamos National Laboratory. Compared to the performance of the conventional C-chicane bunch compressor, the double C-chicane scheme exhibits the capability of utilizing the transverse momentum shift induced by the coherent synchrotron radiation (CSR) in the second C-chicane to compensate that generated in the first C-chicane, resulting in a compressed electron bunch with minimized transverse momentum along the beam. It is also found that the double C-chicane scheme can be designed to significantly better preserve the beam emittance in the course of the bunch compression. This is particularly beneficial for the MaRIE XFEL whose lasing performance critically depends on the preservation of the ultralow beam emittance.