Beam Tests of a New Digital Beam Control System for the CERN LEIR Accelerator

The Low Energy Ion Ring (LEIR) is a major component in the Large Hadron Collider ion injector chain. We have been developing an all-digital beam control and cavity servo system for the RF acceleration in LEIR. The system is housed by VME motherboards that may hold various daughter boards. Fast tasks are executed in Field Programmable Gate Arrays (FPGAs), slower tasks and communication with the software layer above are achieved in Digital Signal Processors (DSPs). We describe a simplified system prototype, which we tested with low intensity beams on the CERN PS Booster (PSB). The aim was to verify the combined DSP+FPGA architecture and the feedback loop dynamics. An additional goal was to deploy and validate novel software concepts, such as reference-functions and timings generation, and user-selectable digital data acquisition.