A localization algorithm for strong sources of orbit motion in the APS storage ring

This paper describes a semi-automatic algorithm that locates spatially discrete strong sources of storage-ring noise that cause beam motion, e.g., noisy power supplies. The algorithm parasitically uses the APS real-time orbit feedback system (RTFS) to obtain orbit data on line, and a response matrix model to compute the confidences for source candidates. It also computes the estimated spectral density of the source. Further rules-of-thumb for source identification and empirical data are also presented.