Orbit noise analysis in Shanghai Synchrotron Radiation Facility storage ring

The analysis of power density spectrum (PDS) and integral PDS has been implemented for orbit noise analysis in the Shanghai Synchrotron Radiation Facility(SSRF) storage ring. The beam position monitor signal processing in Liberas, which are the orbit measurement electronics, and the PDS calculation algorithm (Welch method) are described in this paper. Then the measured orbit noise PDS and integral PDS are presented. The result indicates that the main orbit noise sources are ground vibration, girder resonant vibration and 50 Hz power supply noise. The orbit noise analysis is useful to reduce orbit noise and increase orbit stability.