Beam position monitor troubleshooting by using principal component analysis in Shanghai Synchrotron Radiation Facility

Beam position monitors （BPMs） have been widely used in all kinds of measurement systems, feedback sys- tems and other areas in particle accelerator field these days. The malfunction of a single BPM can cause serious consequences such as the failure of the orbit feedback and the transverse feedback. A troubleshooting has been made to prevent the defective BPMs from affecting the accuracy and stability of the storage ring in Shanghai Synchrotron Radiation Facility （SSRF）. Different types of malfunctions have been successfully identified by using the idea of principal component analysis （PCA）.