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 for measuring 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 and 500 pC are much lower than those measured at high energy injectors.
@article{arxiv.2201.13147,
title = {Slice energy spread measurement in the low energy photoinjector},
author = {Houjun Qian and Mikhail Krasilnikov and Anusorn Lueangaramwong and Xiangkun Li and Osip Lishilin and Zakaria Aboulbanine and Gowri Adhikari and Namra Aftab and Prach Boonpornprasert and Georgi Georgiev and James Good and Matthias Gross and Christian Koschitzki and Raffael Niemczyk and Anne Oppelt and Guan Shu and Frank Stephan and Grygorii Vashchenko and Tobias Weilbach},
journal= {arXiv preprint arXiv:2201.13147},
year = {2022}
}