PS BOOSTER BEAM TESTS OF THE NEW DIGITAL BEAM CONTROL SYSTEM FOR LEIR

We have been developing a scaled-down prototype of the new digital beam control and cavity servoing system for CERN’s Low Energy Ion Ring (LEIR) slated for commissioning in 2005. The system’s hardware and software, developed as part of a CERN-BNL collaboration, are based on new all-digital technology already deployed at BNL's AGS Booster. The system relies on VME modules, carrying Digital Signal Processors (DSPs) as well as Field Programmable Gate Arrays (FPGAs), and daughter cards. New concepts deployed include software implementation, through DSPs & FPGAs, of functions traditionally executed by analogue hardware, such as reference-functions and timings generation. Additionally, a user-selectable digital data acquisition functionality provides diagnostic and troubleshoot access points, a new feature which is very useful in a digital system. The scaled-down prototype implements frequency program, radial steering, phase and radial loops capabilities and it has been tested in CERN's PS Booster (PSB) during the 2004 run. The measured time constants of the different loops agree with the design values. In addition, the generation of reference functions and timings by software, as well as the digital data acquisition scheme have been validated at DSP level. In this paper we describe the prototype used in the PSB tests, both hardware and software, and the operational results obtained. Finally, we present an outline of the final LEIR system and of the roadmap for applying the same technology to other CERN accelerators.