DESY is planning to upgrade PETRA III to a 4th generation light source. The magnetic lattice components are pre-installed and aligned on long girders before being installed in the tunnel. These long girders and the misalignment of the magnets pose a challenge for the PETRA IV lattice, including the storage of the beam in the ring. Commissioning simulations have been performed which showed that relatively high corrector strengths are required for the orbit correction system. A simulation study was performed to demonstrate the possibility of beam-based girder alignment correction to relax the corrector strengths during machine operation. The simulation results are presented and then discussed for later implementation.

The BESSY II Booster has been reliably delivering beam to the storage ring for several decades. As part of an effort to better understand and control beam dynamics in the Booster, new instrumentation, including Libera Spark ERXR beam position processors, has recently been installed and commissioned. These instrumentation upgrades have enabled measurements and corrections of optics parameters throughout the acceleration ramp which were not previously possible, leading to understanding and mitigation of mechanisms for beam loss and instabilities. Here we describe the beam position measurement system, corrections to the tune and chromaticity, and the resulting improvements to the top-up operation of BESSY II.