Slice energy spread measurement in the low energy photoinjector

Physical review accelerators and beams 25(8), 083401 (2022). doi:10.1103/PhysRevAccelBeams.25.083401
Slice energy spread is one of the key parameters in free electron laser optimizations, but its accurate measurement is not straightforward. Two recent studies from high energy (≥100 MeV) photoinjectors at SwissFEL and European XFEL have reported much higher slice energy spread than expected at their XFEL working points (200 - 250 pC). In this paper, a new method formeasuring slice energy spread at a lower beam energy (∼20 MeV) is proposed and demonstrated at the PhotoInjector Test facility at DESY Zeuthen (PITZ), and the results for 250 pC are much lower than those measured at high energy injectors
Published by American Physical Society, College Park, MD