TY  - JOUR
AU  - Wegmann, Christoph Julien
AU  - Lens, Dieter
AU  - Zipfel, Bernhard
AU  - Reinwald, Christoph
AU  - Klingbeil, Harald
TI  - Verification of the Beam Phase Control System Topology for FAIR by Beam Experiments
JO  - IEEE transactions on nuclear science
VL  - 73
IS  - 5
SN  - 0018-9499
CY  - New York, NY
PB  - IEEE
M1  - GSI-2026-00725
SP  - 1812 - 1822
PY  - 2026
N1  -  This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. For more information, see https://creativecommons.org/licenses/by-nc-nd/4.0/
AB  - Beam phase control loops have become an important sub-system of the low-level radio frequency (LLRF) systems of ion synchrotrons. A wide range of different implementations exists today. The LLRF system at the GSI Helmholtzzentrum für Schwerionenforschung (GSI)/Facility for Antiproton and Ion Research in Europe (FAIR) was designed with the particular goals of modularity, flexibility, scalability, and user-friendly diagnostics possibilities. Based on these requirements, a system focused on the time-domain manipulation of all RF and beam signals was developed. This contribution presents the beam phase control system and demonstrates its effectiveness. The special attention is paid to the operation during the acceleration ramp. Results of two independent beam experiments are presented: one focused on examining the control loop behavior and one applying the system in a practical setting. In both cases, the GSI/FAIR beam phase control system successfully dampens longitudinal dipole mode bunch oscillations. Its performance and behavior matches previous analyses.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1109/TNS.2026.3687074
UR  - https://repository.gsi.de/record/368168
ER  -