Effects of insertion device on SSRF storage ring

Shanghai Synchrotron Radiation Facility (SSRF), one of the third generation light sources, aims to produce high brightness and/or high flux X-ray source for users; therefore insertion devices (IDs) are important magnetic elements for SSRF. In this paper, the linear perturbations due to IDs toward its storage ring lattice, such as beta function distortions, tune shifts, emittance growths, and energy spreads are estimated by using analytical formulae, and the nonlinear effects from IDs, especially dynamic aperture, are simulated by using Racetrack code. The results show that (a) the reduction of dynamic aperture from single undulator is negligible, since electron beam energy of 3.5 GeV is high and ID's magnetic field is low, and the beta functions in the middle of straight sections, where ID is located, are well optimized; (b) however, the reduction from single wigglers, especially super-conducting wiggler, is visible, because of its higher magnetic field; (c) effects of each ID on emittance growths and energy spreads are less than 7%.