Low Sensitivity Option for Transverse Optics of the FLASH Linac at DESY

TL;DR

This paper presents a low sensitivity transverse optics design for the FLASH linac at DESY, improving stability and reproducibility of electron beam parameters crucial for free electron laser performance.

Contribution

The paper introduces a novel transverse optics configuration with reduced sensitivity to beam energy and magnet setting variations, enhancing operational stability.

Findings

Optics has been in operation since spring 2006.

Demonstrated superior performance over previous focusing setups.

Improved reproducibility of beam parameters after operational breaks.

Abstract

The aim of the FLASH linac is to create electron bunches of small transverse emittance and high current for the free electron laser facility FLASH at DESY. Available operational experience indicates that in order to optimize SASE signal at different wavelengths or to fine-tune the FEL wavelength, empirical adjustment of the machine parameters is required and, therefore, the sensitivity of the beamline to small changes in the beam energy and in the magnet settings becomes one of the important issues which affects both, the final performance and the reproducibility of the results after breaks in operation. In this article the transverse optics of the FLASH beamline with low sensitivity to changes in beam energy and quadrupole settings is presented. This optics is in operation since spring 2006 and has shown a superior performance with respect to the previous setup of the transverse focusing.