Oct 9 – 13, 2022
FHNW Campus Brugg-Windisch
Europe/Zurich timezone

Consolidation of SwissFEL LLRF system

Oct 12, 2022, 2:25 PM
Lichthof (Building 1)


Building 1

Poster Low Level RF Workshop 2022 Poster Session


Zheqiao Geng (PSI - Paul Scherrer Institut)


SwissFEL LLRF system was well designed with precise RF detection, reliable amplitude and phase feedback, and high degree automation. After the start of user operation, new requirements on robustness and reproducibility have been raised for LLRF. Efforts have been spent to consolidate the LLRF system. We implemented lookup-table-based algorithms for the fast setup of klystrons for desired operating points. Amplitude feedback loops manipulating the klystron high-voltage were implemented for C-band klystrons operating in saturation for long-term stability. We optimized the reference tracking scheme for preserving the beam phase after rebooting or power cycling any LLRF components. The race conditions between LLRF triggers and clocks were smartly handled in LLRF firmware. This poster illustrates these consolidations and their results at SwissFEL.

Primary authors

Mario Jurcevic (PSI - Paul Scherrer Institut) Roger Kalt (PSI - Paul Scherrer Institut) Waldemar Koprek (PSI - Paul Scherrer Institut) Zheqiao Geng (PSI - Paul Scherrer Institut)

Presentation materials