LLRF Topical Workshop on Advanced Feedback Control (TWoAFC)

Session

Control Architecture and Strategies

Oct 13, 2026, 4:15 PM

Nova Gorica, Slovenia

41. Closed-loop Feedback Control of Coupled-bunch Instabilities

Dmitry Teytelman (Dimtel, Inc.)

10/13/26, 4:15 PM

Control Architecture and Strategies

Oral

Bunch-by-bunch feedback control of coupled-bunch instabilities in the last 30 years became a ubiquitous feature of storage rings, both light sources and colliders. In my talk I will introduce the formalism of coupled-bunch instabilities and bunch-by-bunch feedback. Next, I will describe in detail the technology that these feedback systems rely upon. Using measurements from a number of real...

22. Model-Driven Control for High-Stability Magnetron RF Sources

Jon Vivas (University of the Basque Country EHU)

10/13/26, 4:55 PM

Control Architecture and Strategies

Oral

Magnetrons offer high energy efficiency, making them attractive power sources; however, their RF output lacks the phase and amplitude stability required for high-precision applications like particle accelerators. While techniques like RF signal injection have been explored to stabilize magnetron outputs, this research introduces a Low-Level RF (LLRF) control framework designed to enhance...

4. Updates on an S-band Klystron Fast Feedback Loop for Plasma Wakefield Acceleration

Xianghe Fang (INFN-LNF)

10/13/26, 5:25 PM

Control Loop Modeling, Tuning and Optimization

Oral

Beam-driven plasma wakefield accelerators impose extremely stringent requirements on RF phase stability to ensure reliable beam generation and synchronization. At SPARC_LAB, a fast RF feedback system has been developed for the S-band RF power plant to satisfy the facility's synchronization requirement of less than 20 fs RMS phase jitter with respect to the reference master oscillator (RMO)....

14. Operational Experience with the Adaptive Feed-Forward at CERN Linac4

Bartosz Bielawski (CERN)

10/13/26, 5:55 PM

Control Architecture and Strategies

Oral

The CERN Linac4 low-level RF relies on an adaptive feed-forward (AFF) to correct the beam-loading transient that the field feedback (PI or LQG) cannot remove within a single pulse. The AFF learns a correction from the field error of previous pulses and reduces the beam loading at the batch start to below 0.4%, a factor of two better than the specification. Over several years of operation we...

3. Intra-Pulse RF Phase Stabilization in LLRF Systems

Borut Baricevic (Instrumentation Technologies d.o.o)

10/14/26, 2:45 PM

Control Hardware Platforms

Oral

Achieving high RF field stability in accelerating cavities driven by microsecond-scale pulses remains a challenge for modern LLRF systems. The short pulse duration limits the implementation of conventional FPGA-based intra-pulse feedback, while pulse-to-pulse correction alone cannot fully compensate for phase perturbations introduced by the high-power RF chain.
An implementation of this novel...

40. Lowpass Differentiator Controllers for the Longitudinal Bunch-by-bunch Feedback

Dmitry Teytelman (Dimtel, Inc.)

10/14/26, 3:15 PM

Control Architecture and Strategies

Oral

Modern diffraction-limited storage ring light sources run at high beam currents and use harmonic cavities to lengthen the bunches for increased lifetime. These features make feedback control of the longitudinal coupled-bunch instabilities very challenging due to the bunches' wideband and variable dynamics. In the last few years, the long-ignored idea of using a differentiator as the feedback...