Design and Commissioning of A Beam Distribution System for Multiple Undulator Line Operation of the SXFEL-UF

TL;DR

This paper details the design and commissioning of a beam distribution system for SXFEL-UF, enabling simultaneous operation of multiple undulator lines while maintaining beam quality and suppressing collective effects.

Contribution

It presents the detailed physics design and successful commissioning of a beam distribution system for SXFEL-UF, supporting multi-line operation with preserved beam properties.

Findings

Successful implementation of the beam distribution system.

Effective suppression of collective effects like dispersion and micro-bunching.

Achievement of stable multi-line operation with maintained beam quality.

Abstract

As an important measure of improving the efficiency and usability of X-ray free electron laser facilities, simultaneous operation of multiple undulator lines realized by a beam distribution system has become a standard configuration in the recent built XFEL facilities. In Shanghai, SXFEL-UF, the first soft X-ray free electron laser user facility in China, has finished construction and started commissioning recently. Electron beam from linac is alternately distributed between the two parallel undulator beam lines by a beam distribution system with a 6{\deg} deflection line. The beam distribution system is designed to keep the beam properties like low emittance, high peak charge and small bunch length from being spoiled. Beam collective effects such as the dispersion, coherent synchrotron radiation and micro-bunching instability should be well suppressed to guarantee the beam quality. In this work, the detailed physics design of the beam distribution system is described and the recent commissioning result is reported.