• C. Yao, W.E. Norum, J. Wang
  ANL, Argonne

The Advanced Photon Source (APS) injection booster is a 7-GeV electron synchrotron with a ramping time of 220 ms and a repetition rate of 2 Hz. A real-time tune measurement system is needed in order to monitor and possibly correct tune drift during the 220-ms energy ramp. Such a drift may occur during user beam operations, especially during top-up operations, and results in shot-to-shot charge fluctuations. We designed and developed a new FPGA-based system that pings the beam at variable intervals and measures booster tune. A prototype system has been built and tested, and it has achieved the specified time resolution of 2 ms and a tune resolution of better than 0.002. This report describes the design and main parameters, test results from our preliminary commissioning, and application of such a system in ramping correction.