Development of High Performance Electron Beam Switching System for Swiss Free Electron Laser at PSI

TL;DR

This paper presents the development and testing of a high-performance electron beam switching system for the SwissFEL, aiming to improve beam separation stability for enhanced X-ray pulse production.

Contribution

It introduces a novel electron beam switching system combining a high Q-factor resonant deflector and a DC septum magnet, with prototype results demonstrating its effectiveness.

Findings

Achieved shot-to-shot deflection stability of <+/-10 ppm in amplitude.

Demonstrated timing stability within +/-100 ps.

Validated the performance of the kicker prototype.

Abstract

A compact X-ray Free Electron Laser (SwissFEL) is under development at the Paul Scherrer Institute. To increase facility efficiency the main linac will operate in two electron bunch mode. The two bunches are separated in time by 28 ns and sent to two undulator lines. The combination of two beam lines should produce short X-ray pulses covering wavelength range from 1 to 70 {\AA} with submicron position stability. To separate the two bunches, a novel electron beam switching system is being developed. The total deflection is achieved with a combination of high Q-factor resonant deflector magnet, followed by a DC septum magnet. The shot-to-shot deflection stability of the entire switching system should be <+/-10 ppm in amplitude and +/-100 ps in time, values which present severe measurement difficulties. Deflection magnets requirements, development and results of the kicker prototype are presented.