Nonlinear dynamics in the Duke storage ring with FEL wigglers

Single particle dynamics in the storage ring can be significantly influenced by strong nonlinearities from long and strong-field insertion devices. This paper reports our preliminary results on the dynamics impact of the 24 m long OK5 FEL in the Duke ring. Initial studies are performed using an intermediate lattice with two OK5 wigglers. The dynamic aperture is computed using a recently developed symplectic wiggler integrator and the frequency map technique, NAFF We have observed significant dynamic aperture reduction due to OK5 wigglers at lower beam energies. We also report our preliminary findings on the means to improve beam dynamics with wigglers.