Development of Low Level RF Control Systems for Superconducting Heavy Ion Linear Accelerators, Electron Synchrotrons and Storage Rings

Since 2001 ACCEL Instruments is supplying low level RF control systems together with turn key cavity systems. The early LLRF systems used the established technology based on discrete analogue amplitude and phase detectors and modulators. Today analogue LLRF systems can make use of advanced vector demodulators and modulators combined with a fast computer controlled analogue feed back loop. Feed forward control is implemented to operate the RF cavity in an open loop mode or to compensate for predictable perturbations. The paper will introduce the general design philosophy and show how this can be adapted to different tasks as controlling a synchrotron booster nc RF system at 500 MHz, or a sc storage ring rf, as well as a the superconducting 176 MHz accelerating cavities of a linear accelerator at 176 MHz with multiple cavities individual driven and controlled.