Measurement of transverse damping time on BEPC

In BEPC, the oscillation information of the beam position of a single bunch in every turn can be tracked by the bunch-by-bunch system, through which the relationships between the transverse damping time and the beam current, chromaticity, octupole current and beam energy were obtained. The radiation damping time acquired in the experiment was 52 ms. The data analysis result of the bunch-by-bunch tracking experiment indicates that the higher the beam current is and the higher the chromaticity is, the higher the damping ratio is, and that the change of the octupole current has little influence on the damping ratio when the beam current is 4.7 mA. The damping ratio decreases with the rising of the beam energy when the beam current is 5 mA.