Operation of the Kara booster in storage-ring mode for accelerator studies and system development

The Karlsruhe Research Accelerator (KARA) booster syn- chrotron, normally used to accelerate electrons from 53 MeV to 500 MeV for injection into the KARA storage ring, has recently been successfully operated in a stand-alone storage ring mode. This capability was enabled by the moderniza- tion of its magnet power supplies and their integration into an EPICS-based control system. Operating the booster in this mode provides a flexible platform for accelerator physics studies, including the development of energy-ramping pro- cedures, characterization of magnet hysteresis effects, and verification of control strategies under low-energy storage conditions. Initial commissioning demonstrated stable beam storage at several energies up to 500 MeV. The future compact storage ring cSTART, designed for energies of 50-90 MeV, is currently being constructed at KIT. The new power supplies allow preliminary experiments to be conducted across this energy level in the KARA Booster, enabling studies of beam and machine characterizations un- der realistic conditions. Additionally, the ability to store beam up to 500 MeV supports tests relevant for the KARA storage ring. This mode establishes the booster as a compact and flexible experimental platform prior to deployment in cSTART and the main KARA storage ring. Future work will focus on beam dynamics and diagnostics in the lower energy region with reduced radiation damping, as well as optimization of ramping cycles for stable injector operation.