Asynchronized energy ramping at SRRC storage ring

The 1.3 GeV storage ring at SRRC will provide an ultra-violet to soft X-ray radiation source to the potential users. The energy ramping of storage ring will push the critical photon energy to the edge of hard X-ray. There are several ways to ramp the electron energy, for example, increasing the extraction energy to 1.5 GeV from booster directly, ramping the magnets' power supplies with synchronized function generators, or asynchronized ramping of magnets at storage ring, etc. The tune drifting during the ramping procedure is expected and should be minimized such that the beam can survive through the ramping process. The betatron frequencies and ramping function of magnets were carefully monitored in order to avoid the betatron tunes cross the resonance line. A successful asynchronized ramping result will be presented in this paper.