Fourth-integral resonance study on Alladin at SRC

The fourth-integral betatron resonance driven by sextupoles was studied on the electron storage ring Aladdin at SRC. The resonance feature of capturing the phase space particles in the resonance islands was dearly demonstrated. In a computer simulation, the finite beam size is simulated by multi-particle tracking and the decoherence of the betatron oscillation was shown to agree well with experiment observation.