Advanced Photon Source Upgrade (APS-U) storage ring, currently in installation and testing, is set for beam commissioning in early 2024. In the APS-U storage ring, there are 560 Beam Position Monitor (BPM) pickups, each equipped with high resolution electronics. This paper presents outcomes from pre-beam testing and beam commissioning of the APS-U BPM system. We discuss tailored features for advanced beam measurements, testing methodologies, challenges, and successful integration into the storage ring. Our findings demonstrate the robustness of the BPM system, emphasizing its crucial role in achieving the first beam and optimizing the APS-U storage ring's performance.

The BPM feedthroughs were manufactured and tested at the vendor and the APS lab. All feedthroughs were sorted in groups of four according to their capacitance. Four feedthroughs with close capacitance were welded to the housing in an assembly. The assemblies were measured in the APS lab to confirm their electrical performance acceptable and their x/y offsets were calculated according to VNA data. After the BPM assemblies were installed in the SR, they were measured again to verify their connections. The x/y offsets including the cables were compared with the previous data and will be used as the reference in beam commissioning. The testing results at the vendor, APS lab and APS-U SR were analyzed.

Transverse bunch-by-bunch (BxB) feedback system has been designed, fabricated, installed, and tested with beam at the Advanced Photon Source Upgrade (APS-U) storage ring. The transverse feedback system (TFB) is designed to suppress coupled bunch instabilities and single bunch instabilities. It adapted a stripline kicker design which has the same profile as the APS-U injection/extraction kickers. The system uses digital controllers which provide powerful diagnostics, in addition to its major functionality for feedback control. This paper presents the status of the TFB system including early beam commissioning results.