Real-time tune monitor system on Shanghai Synchrotron Radiation Facility

The storage ring at Shanghai Synchrotron Radiation Facility (SSRF) is operating at the top-up mode, which is injected every 10 minutes. The transverse betatron oscillation introduced during the injection can be used to calculate the tune of the machine. A real-time tune measurement system has been built where the Fast Fourier Transformation (FFT) of the turn-by-turn beam position data from digital BPM processors is calculated at injection rate. Long-term results of the first half of 2014 show that the system is capable of monitoring tune shift effectively, and can be used to evaluate the best tune performance of the storage ring. Meanwhile, the system can detect operation abnormality in time and locate the malfunction causes effectively after analyzing related systems. It is an effective tool for the operation and optimization of the machine.