Optimization and modeling studies for obtaining high injection efficiency at the Advanced Photon Source

In recent years, the optics of the Advanced Photon Source storage ring has evolved to a lower equilibrium emittance (2.5 nm-rad) at the cost of stronger sextupoles and stronger nonlinearities, which have reduced the injection efficiency from the virtual 100% of the high emittance mode. Over the years we have developed a series of optimizations, measurements, and modeling studies of the injection process, which allows us to obtain or maintain low injection losses. The above will be described along with the injection configuration.