Detailed studies of the effects of solenoid misalignment and development of beam-based alignment methods for FLUTE

FLUTE (Ferninfrarot Linac- Und Test-Experiment) is a versatile linac-based test facility at the Karlsruhe Institute of Technology (KIT). It is designed to generate strong ultra-short THz pulses and to provide a platform for detailed accelerator studies and diagnostic development. The aim of wideband THz generation requires electron bunches with a length of a few femtoseconds, therefore a photoinjector is used as electron source. Shortly after the photoinjector, a solenoid is installed to focus the initially diverging beam. Accurate alignment of the magnet is required to avoid transverse deflection of the beam when adjusting operational parameters such as the beam energy or the focal length of the magnet. This presentation provides a detailed study on the effects of solenoid misalignment based on numerical tracking simulations for the FLUTE injector section. Based on this study, an iterative beam-based alignment procedure has been developed. In addition, this contribution provides a proof-of-concept for a software routine that fits the results of simulations to measurement data and, thereby, determines the misalignment of the solenoid.