EXPERIMENTAL DETERMINATION OF THE TIMING STABILITY OF THE OPTICAL SYNCHRONIZATION SYSTEM AT FLASH

摘要

An optical, long-term stable synchronization system with an accuracy of better than 10 fs is presently being installed at the free electron laser FLASH. A periodic laser pulse train from a mode-locked, erbium-doped fiber laser is distributed via length stabilized fiber links. In this paper, we present measurements of the timing stability of the optical distribution system. Two bunch arrival time monitors (BAMs) are used to measure the electron bunch arrival times at two positions in the linac, separated by 60m. Each BAM is supplied with fiber laser pulses by its own fiber link. By correlating the measured arrival times of the same electron bunches, the overall performance of the optical distribution system and the BAMs can be evaluated. A resolution and timing stability of better than 10 fs has been achieved.