Failure Tolerant Operation and Trimming Principle in the CLIC Main Linac

A powering strategy for a high number of magnets disposed in a radiated and confined area is presented for a particle accelerator application. One power converter supplies the main current in series connected magnets. Then, for adjusting each current individually, small active trimmers are implemented together which each magnet. The trimmers are only dissipative, implemented as MOSFETs operated in their linear region and controlled by analog PI controllers. The reliability of the whole powering system is ensured with failure tolerance that complies with beam physics. The steady state operation and dynamic response in case of failures are experimentally studied in a reduced scale prototype.