FIRST RESULTS FROM THE BUNCH ARRIVAL-TIME MONITOR AT THE SwissFEL TEST INJECTOR

A bunch arrival-time monitor (BAM) based on a Mach- Zehnder type electro-optical intensity modulator is under development at PSI to meet the high requirements for stable SwissFEL operation. The timing precision is derived by a stable pulsed optical reference system. The first BAM is located upstream of the bunch compressor where the bunch energy is 250 MeV and the pulse length is approximately 3 ps. At this position, the bunch arrival time is sensitive to the laser- and gun timing. In this paper, we report on the commissioning of the RF- and optical front ends, the first arrival-time jitter and drift measurements.