Synchronous phase measurement and study at the Taiwan Photon Source

A bunch-by-bunch synchrotron phase detector system has been implemented to investigate the synchronous phase behavior of the storage ring at the Taiwan Photon Source. This detector employs I/Q demodulation to cal-culate the beam phase on a bunch-by-bunch basis. The acquired data is integrated into the accelerator control system, visualized through a graphical user interface, and made available for further analysis. Independent component analysis (ICA) is employed to identify under-lying sources. For a trapezoid-like filling pattern, transi-ent beam loading effects are clearly observed in the flat-top region, whereas significant phase variations occur along the sloped edges of the pattern. During the beam decay period, an in-phase synchrotron phase oscillation at 7 kHz is observed, which originates from the rotation frequency of the radio-frequency transmitter. During injection, three distinct modes are identified through ICA decomposition. Among them, the amplitude of the syn-chronous oscillation mode shows a strong dependence on the injected bucket address.