ANL, Argonne, Illinois, USA
APS Upgrade will feature an entirely new storage ring but will keep the existing injector complex consisting of the linear accelerator, Particle Accumulator Ring (PAR) and Booster. Due to small dynamic aperture of the APS Upgrade lattice, swap-out injection is adapted when an entire old bunch is replaced with a new bunch. This injection requires Booster to provide high-charge bunches with up to 17 nC in a single bunch. An extensive work is being carried out on characterizing the existing injector rings to ensure future high-charge operation. In this paper, we will present results of the lattice measurement using the response matrix fit. We will show the analysis of the achievable lattice measurement accuracy in the APS Booster and describe fit parameter modifications required to achieve good fit accuracy for the PAR.
ANL, Argonne, Illinois, USA
BNL, Upton, Long Island, New York, USA
Fermilab, Batavia, Illinois, USA
Next-generation, high-performance storage ring light sources based on multibend achromat optics will require on-axis injection because of the extremely small dynamic aperture. Injectors will need to supply full-current bunch replacement in the ring with high single-bunch charge for swap-out. For upgrades of existing light sources, such as the Advanced Photon Source Upgrade (APS-U), it is economical to retain the existing injector infrastructure and make appropriate improvements. The challenges to these improvements include achieving high single-bunch charge in the presence of instabilities, beam loading, charge stability and reliability. In this paper, we discuss the rationale for the injector upgrades chosen for APS-U, as well as backup and potential alternate schemes. To date, we have achieved single-bunch charge from the injectors that doubles the original design value, and have a goal to achieve about three times the original design value.
