BEAM DYNAMICS STUDY FOR PETRA III INCLUDING DAMPING WIGGLERS

Damping wigglers will be installed in the storage ring PETRA III to control the beam emittance to 1 nmrad. These wigglers will produce linear and non-linear perturbations on beam dynamics. The wiggler fields are derived from numerical field calculations. Halbach equations are used to describe the wiggler field analytically. A new expanded transport matrix method is developed to solve linear dynamics, and used to match linear lattice functions. The symplectic method is adapted to track particle through the whole ring including the damping wigglers. According to presently known field quality, the non-linear effects of damping wigglers will not degrade the performance of PETRA III. The dynamic aperture is still larger than the physical aperture