Linac and transfer line beam position monitor at ELETTRA

A Beam Position Monitor (BPM) system, based on Log Ratio detectors (Bergoz LR-BPM), has been designed, built and commissioned at ELETTRA. Currently, the system is installed on the ELETTRA Linac and Transfer Line and it is integrated in the ELETTRA control system. The system is being used to monitor the trajectory along the Transfer Line; in the Linac, it monitors and controls the Linac beam stability. Furthermore, the Transfer Line BPMs are integrated in the program TOCA for the correction of the trajectory and the optimisation of the injection efficiency. The paper describes the system and the measurements performed both in laboratory and on the ELETTRA electron beam. Future possible applications of the LR-BPM system for the upgraded ELETTRA Linac, to be used for the new seeded FEL source, are here briefly presented. (authors)