BNL, Upton, Long Island, New York, USA
NSLS II storage ring RF system has the digital ramp control function, enabling rapid change of the cavity phase and amplitude. This, together with largely overcoupled RF cavity and transmitter geometry, enables the possibility to "ping" the beam in longitudinal phase space. Similar to the pinger commonly used for transverse beam dynamic studies, the RF jump presents with a powerful tool for investigation of the machine longitudinal beam dynamics. During our beam studies, RF phase was jumped within a short interval of time (less than synchrotron period). Using turn-by-turn data from BPMs we measured the machine energy acceptance with and without damping wigglers. This paper presents the beam study results.
